Tm.^- S-xvs-^^l THE QUARTERLY JOURNAL LITERATURE, AND ART. OCTOBER TO DECEMBER, 1828. LONDON: HENRY COLBURN, NEW BURLINGTON-STREET. MDCCCXXVIII. ( LONDON: Fruited by WILLIAM CLOWES. Staiiiford-Street. CONTENTS-JULY TO SEPTEMBER, 1828. Pag* An Account of some of the Steam-Boats navigating the Hudson River in the State of New York. In a Letter from Mr. Ren- wick, Professor of Natural and Experimental Philosophy and Chemistry in Columbia College, to Captain Edward Sabine, R. A., Secretary of the Royal Society 1 Communication on the Structure and Economy of the Greenland Whale, made at the Royal Institution of Great Britain. By J. Harwood, M.D. F.R.S., &c. . . . .10 On the Inland Navigation of the United States of America, PartlL . . . . . .24 On Malaria on Ship-board. By Dr. Mac Culloch . . 38 Lineaments of Leanness. By William Wadd, Esq., F.L.S. . 76 On the Curative Influence of the Southern Coast of England, especially that of Hastings. By William Harwood, M.D. reviewed . . . . , ,85 On Ornamental Aviaries .• • • ,100 Observations on the Force of our Ships of War , .108 An Account of a New Genus of Plants called Diplogenea. By John Lindley, Esq. F.R.S., &c. . . .121 A Dissertation on the Nature and Properties of the Malvern Waters, reviewed. By W. Addison, Surgeon . .123 On Mr. Ivory's Investigations of the Velocity of Sound. By Mr. Henry Meikle . . . .124 Description of a Regulating Valve for a Gas Establishment . 135 Transactions of the Horticultural Society. Vol. vii. Part II. . 138 An Attempt to prove that Ava was the Ophir of Solomon. By John Ranking, Esq. . , . . .141 On the Sap of the Rose Tree, Communicated by R. Addams, Esq. 147 Statistical Notices suggested by the Actual State of the British Empire, as exhibited in the last Population Census. By Mr. Merritt . . . • • 150 CONTENTS. Proceedings of the Horticultural Society , • Astronomical and Nautical Collections. i. Elementary View of the Undulatory Theory of Light. By M. Fresnel ..... ii. Principal Lunar Occnltations of the fixed Stars, in the months of November and December, 1828, and January, 1829, calculated for the Royal Observatory at Greenwich. By I. Hendsrson, Esq. . * Page 164 168 192 MISCELLANEOUS INTELLIGENCE, I. Mechanical Science. Page 1 TuUey'a New Catadioptric Microscopes 193 2 Carpenter's Aplanatic Solar Microscope 194 3 Improvement in the Barometer 195 4 Effect of the Moon upon Baro- metric Pressure ib. 5 On the Arrangement of Water Pipes in the Streets 196. C New Razor Straps 197 7 On the Fusion of Tallow ib, 8 Method of hardening Plaster Casts and Alabaster 198 9 Injurious Colours ib. 10 Method of preventing Milk from turning sour 199 11 Internal change in the Po- sition of Particles in Solids . . ib. II. Chemical Science. 1 Conducting Power of Metals for Electricity 199 2 Conducting Power of different Fluids for Voltaic Electricity 200 3 Influence over the Electric Powers of Metals ib. 4 On the secondary Piles of Ritter ib. 5 Comparison of the Tourmaline and bad electro-conductors ... 201 (i Electro-magnetic Current from heated fluids 202 7 Purity of Metals tested by the Galvanometer 203 8 Construction of Magnetic Needles.. ii. D Alteration of Brass Wire in the Air 204 10 New Solar Phosphor! ib. 11 Preparation of Iodine 205 12 Action of Ammonia on heated Metals ib. 13 IMethod of collecting Air for Analysis 20G 14 On the Hypo-phosphites ib. 15 OuPyrophorus 207 16 Test of Potash by Nickel, before the blow-pipe 209 17 New Variety of Borax ib, 18 Mutual Action of Nitre and Sal- Ammoniac ib, 19 Preparation and Properties of Aluminum, &c ib. 20 Chloride of Glucinum 211 21 Metallic Cerium ib, 22 Use of Chameleon Mineral for marking Linen 212 23 Reduction of Oxide of Copper by Ii'on and Water 213 24 Separation ofSilver and Copper ib, 25 Solubility of Sulphate of Lead ib. 26 Use of Red Sulphuret of Ar- senic, or Realgar, in dyeing ib, 27 Opaque and Transpai-ent White Arsenic 214 28 Reduction of Snlphuiiet of Arsenic ib, 29 On a ne w use of the Chromate of Potash 215 30 Chloride of Silver and Sodium 21G 31 Nitrate and Sulphate of Am- monia and Silver ib. CONTENTS. m Page 32 Artificial production of Ultra- marine ib. 33 On an economical Method of dissolving Metals in Acids in the Manufacture of certain Metallic Salts 217 34 Infusible Crucible 219 35 Sugar of Liquorice ib. 36 On the Preparation of Tannin 220 37 Vegetable Gelatine, and Albu- men > 221 Page 38 Preparation of Pi peri ne 221 39 Substitute for the Sulphate of Quinia 222 40 Citric Acid from Gooseberries ib. 41 Nature of Aloetic Acid, or the Bitter of Aloes 223 42 Preparation of Gallic Acid. . ib. 43 Volatilization of Alcohol ib. 44 Concentration of Alcohol by Animal Membrane 224 45 Formation of Adipocire 225 III. Natural History. 1 Mean Height of the Inhabit- ants of Paris, &c 220 2 Effects of the Tincture of Col- chicum Autumnale on the System ib. 3 Gouty Inflammation cured by Vaccination 227 4 Effect of Chlorine in Chronic affections of the Lungs ib. 6 Sting of a Wasp ib. 6 On Insects inclosed in Copal., ib. 7 Reproduction and use of Leeches ... 228 8 Red Viper of Dorsetshire ib. 9 Destruction of Grasshoppers' Eggs 229 10 Loss in weight of Meat during cooking ib. 11 Living Giraffes in Europe ... ib. 12 Easy Method of preserving small Birds ib. 13 German Method of procuring Flowers in Winter ib. 14 Chinese Method of Planting Branches 230 15 On a Plant living entirely in the Air ib. 10 Culture of Aquatic Plants in China 231 17 Benzoic Acid in the Grasses., ib. 18 Eradication of Meadow Saffron ib. 19 Native Arseniuretted Iron ... ib. 20 Muriate of Ammonia in Tur- kistan 232 21 New Minerals containing Se- lenium ib, 22 Common Salt on the Coast of Chili ib. 23 Fall of an Aerolite and accom- panying Phenomena 233 24 Meteor exhibiting a peculiar Green Colour " ib. 25 On the ascent of the Jung Frau ib. 26 Active ]\Iolecules in Organic and Inorganic bodies 235 Meteorological Table for June, July, and August 236 TO OUR READERS AND CORRESPONDENTS. We have been favoured with Communications from Mr. Burnett, Mr, Kendal, and Mr. Jackson ; they reached us too late for publication in the present Number. We have seen Mr. Quarrill's new Table Lamp, and decidedly prefer it to any of its predecessors, as being perfectly sinumbral ; of an elegant form ; and, what is most important, simple in its construction and management. The want of a proper drawing and section has prevented our giving a more detailed description of it. Our Correspondent at Tringham has furnished us with nothing new. The Letter on Agricultural Chemistry is reserved. In the Table of Contents to our last Volume, the Title of the following Paper was accidentally omitted : — On the concealed Agency of Carbonic Acid in determining the Decomposition of Water by the Contact of Iron. By Marshall Hall, M. D., F. R. S. E., &c. ... 262 THE QUARTERLY JOURNAL OP SCIENCE, LITERATURE, AND ART. An Account of some of the Steam-Boats navigating the Hudson River in the State of New York. In a Letter from Mr. Renwick, Professor of Natural and Experimental Philo- sophy and Chemistry in Columbia College, to Captain Edward Sabine, R.A., Secretary of the Royal Society. You ask of me some further particulars in relation to the steam- boats on the Hudson, that I mentioned to you as so remark- able for their speed. I shall endeavour to give you all the information on this subject that is in my power. Immediately upon the decision of the question between the re- presentatives of Chancellor Livingston and Fulton, and those who contended for a free navigation, by which decision the exclusive grant vested in the former by the State of New York was set aside, several companies undertook the construction of passage- boats propelled by steam. Two of these were mere copies of the boats of Fulton, but lighter in frame, and propelled by engines more powerful in proportion ; they, therefore, exceeded the boats of the old company in speed. Two others were con- structed princi[)ally for the purpose of towing each a large pas- sage-boat. These were fitted up in a splendid manner ; and, from the comparative safety and comfort which they afforded, it was the general anticipation that they must obtain a prefer- ence. Various other boats, from other lines of communication, were also put upon the river ; but no expectation seems to have existed at first, that it would be possible to make the passage to JULY—SEPT. 1828. B 2 Account of Steam-boats or from Albany between sunrise and sunset. All these boats were upon the low pressure principle, with condensing engines differing only in detail from the double engine of Watt. Many months, however, had not elapsed, before an attempt was made to shorten the passage by the employment of more powerful means of propulsion. A boat was constructed upon a model apparently well adapted for quickness, being very similar to that of a fast sailing ship. This boat was furnished with an engine on the plan of Woolf, with two cylinders, one of which acted by high pressure, the other receiving steam of the first, as a condensing engine. This vessel, it was hoped by the proprietors, would be able to perform the passage be- tween New York and Albany in about twelve hours. She did not, however, succeed in this ; her average passages being at least sixteen hours. A similar attempt was made by means of a boiler generating high steam, communicating with a cylinder of more than the usual length, and acting then by its expan- sion ; the steam being afterwards condensed. This boat also failed in realizing the anticipations of its proprietors. The competition produced by the increased number of steam- boats, all of them much less costly than the boats of the Fulton company, had such an effect upon the price of the passage, that that association could no longer continue the contest ; its boats were therefore withdrawn, and sold to persons who have applied- them to other objects. When the representatives of Fulton had thus withdrawn from the contest, the Messrs. Stevens, sons of one of the original researchers for the method of propelling boats by steam, entered into the competition. These gentlemen had hitherto kept aloof from it, from highly honourable and deli- cate feelings, being unwilling to assist in destroying the prospects of the heirs and other representatives of Livingston and Fulton. When, however, they found that this company had abandoned the hope of maintaining a successful competition, and had withdrawn their boats, they felt no longer precluded from avail- ing themselves of a privilege, now opened to all. Their first step was to bring round from Philadelphia a new vessel they had constructed there for the navigation of the Delaware. Upon that river no exclusive privilege had ever existed, and. navigating the Hudson River, 3 hence had arisen a continual trial of skill in the increase of the speed of steam-boats. This vessel, on trial, was found to be superior to any that had been before constructed. Placed upon the Hudson, the passage to Albany was readily made by her in the average space of fourteen hours. Leaving either place at sunrise, the distance was therefore performed during the summer season, before the daylight ended. The introduction of this boat caused a complete change in the plan of travelling, which, instead of being principally per- formed during the night, was now rendered practicable during the day ; a change extremely agreeable to voyagers in pursuit of pleasure, and convenient to men of business from its rapidity. Some of the improvements in this boat I shall particularize when I speak of the last and most perfect boat of the same proprietors. Contemporaneous with the introduction of this vessel upon the Hudson, the same gentlemen commenced the construction of another, upon nearly the same model, but with an engine of greater proportionate power. A faulty casting, however, ren- dered the engine incapable of working as well as it ought to have done, and no increase of speed was at first obtained. For. my own part, I must confess that I had come to the conclusion, that the speed now obtained was probably the maximum. I founded this opinion on the fact, that a wave unexampled in any former case was raised in front of these rapidly moving boats. The theory of Juan, showing that this cause of resistance, although insensible at slow velocities, in- creases with their fourth power, pointed out a final limit to the attainable speed. That the maximum was reached, I inferred from the fact that the second boat, although propelled by a more powerful engine, was not more rapid in her motion than the first. I was unaware at the time of the faulty part of the engine ; but that I was in some measure correct is shown from the fact, that although the engine has been since put in perfect order, the acceleration bears but a small proportion to the difference of power. Mr. Robert L. Stevens, however, viewed the subject in another light. Aware of the resistance growing out of the B 2 4. Account of Steam-boats wave, he did not consider it insuperable, but conceived that, by a change in the figure of the prow, it might be in a great mea- sure removed. The shape of the bow of the boats I have men- tioned, departed in some degree from that formerly employed. Mr. Fulton, in his earlier boats, had employed flat bottoms, and prows nearly of the shape of a wedge with plane surfaces. I recollect, even at that early date, having combated the pro- priety of this plan in a conversation I had with him. The changes that he and his imitators subsequently made, were, however, rather grounded upon the necessity of increasing the strength of the vessels by regular curves in their moulds, than from a conviction of the error in the principle. The last boats built under his own directions, resembled in form vessels in- tended to be propelled by sails, but of a small draught of water. Mr. Stevens, from experience, and a just view of the princi- ples, was led to a different conclusion ; and hence the stem of his vessels, which, above the water line, had the usual rake and curvature, began there to incline much more rapidly towards the plane of the keel than is usual, and thus the entrance of the vessel into the water partook at least as much of the inclined plane as of the wedge. But the change of form was too abrupt, and hence the enhanced height of the wave raised by a rapid motion. In this state of the case, he instituted a set of experiments on the motion of figures of different forms through the water, at different velocities. The results of these, as he has stated them to me, are curious. The most remarkable is, that differ- ent forms are different in their good properties at different ve- locities. Upon the basis of these experiments, he commenced the building of a third boat, which I shall now proceed to de- scribe to you. The extreme length of this vessel (the North America) upon deck is 178 feet ; her breadth of beam 28 feet ; the depth of hold 9 feet. Her general figure I cannot better describe to you than by comparing it to the bowl of a table-spoon. The cut- water has a great rake, but in a uniform and regular curve ; and all the curves upon the bottom are regular, and without finy abrupt angles. The sternpost, to increase the power of navigating the Hudson River, 5 the rudder, is vertical ; an unusually large mass of dead wood therefore exists towards the stern, while there is but little near the bow. I have not considered it proper to apply to Mr. Stevens for a draught of the hull of this vessel, as it would be unfair to ask him to disclose what is his only safety from the imitation of his competitors. The North America is impelled by two condensing engines, each of the estimated power of 85 horses. These, with the boilers, are placed upon a platform, formed by a prolongation of the beams of the deck, until they meet the wheel guards, which are carried in a regular sweep from the stem to the stern of the vessel. The breadth of the deck, afore and a])aft the buildings which inclose the wheels and machinery, is therefore considerably increased^ while an uninterrupted pas- sage is left between them from the stem to the stern of the vessel. An advantage similar to the last is gained in the cabins beneath, which, by opening folding doors, may be thrown into one suite from the cabin windows to the bow. The wheels are 13 J feet in breadth, and 21 feet in diameter. There is a peculiarity in their construction which I conceive to be one of the most important of the improvements for which steam navigation is indebted to Mr. Stevens. Experience had shown that a multiplication in the number of paddles (as is the case in an undershot water-wheel, and is there of value) is injurious in a steam-boat. The best arrangement is, that when one paddle is vertical, the preceding one shall be just quitting the water, and the succeeding entering it; in this way no more than two paddles can be in the water at a time, while a water-wheel works best when there may be four. There appears to me to be an obvious reason for the difference between a wheel propelled by a water-fall, and one acting upon water as a resistance to propel a vessel. In the first case it is advantageous to check the forward motion of the water ; in the second, the paddle will act with most power upon water at rest, with respect to the surrounding mass. Now the more numerous the paddles, the greater the agitation that is pro- duced ; and each will in succession strike on water following in the wake of that which has preceded it, and which there- fore acts as a less powerful resistance. But the paddles strike B Account of Steam-boats the water obliquely, instead of entering edge-wise. Each, therefore, meets a sudden resistance, that reacts as a shock upon the engine ; and, in a small number of paddles, these shocks are not only greater, but, being less frequent, oppose a much more unequal action to the moving power. Both the boat and engine have been found to suffer extremely from this cause. I have been informed that it has been corrected in England, by inclining the plane of the paddle to the axis of the wheel, so that the edge of the blade enters the water first at one corner, and is immersed gradually. But in this construc- tion the force is exerted obliquely, and constantly to a disad- vantage ; much power will therefore be lost. To understand the improvement of Mr. Stevens, you have only to consider the water-wheel to be sawn into three parts, one of these to be removed back one-third, and another two- thirds of the distance between the original place of the first paddle and that which succeeds it. The water-wheel may, therefore, be considered as triple ; and as each paddle will form a wake little broader than itself, those of each separate wheel will strike upon water at rest, in relation to the surrounding fluid. The force of the blow is, however, but one-third of what it is in a continuous paddle, and the succession so rapid as to oppose almost a constant resistance to the engine. Such a wheel, therefore, so far from rendering the motion irregular, acts as a fly, and that part of the machinery, of such vital importance in the boats of Fulton, is entirely omitted in those of Stevens. . Of the engines by which this boat is propelled, I have little to say : they are, in almost every respect, identical with the engine of Watt. But one essential difference, that I have noted, is, that the air-pump has more power than is usual. It will therefore keep up a vacuum in the condenser, even when the steam has a greater pressure than is usual in engines in ordinary situations. In the boats of the Fulton company it occasionally happened that, in anxiety to obtain speed, the steam-gauge was permitted to rise to 15 inches. This did not, however, cause an increase of power at all proportioned to t^e increased pressure ; for an air-pump of the proportions of namgating the Hudson River, 9 Watt's engines was not sufficient to free the condenser from steam, and maintain a proper vacuum. In order to be pro- vided for such a case, Mr. Stevens makes, as 1 have stated, his air-pump of greater power. In the North America, however, it has been unnecessary to employ it, for in two passages I have made in her, (one of them the most rapid she ever per- formed,) the steam-gauge never rose above eight inches. Nor do I consider that she has ever yet been brought up to her greatest speed, as even with this comparatively low pressure the steam was cut off at the half-stroke, and permitted to act by its expansive force. Mr. Stevens, I believe, is of opinion, that the boilers are sufficient to supply steam of 12 or 14 inches during the entire stroke of the engine, while the air- pump has power to maintain, at the same time, a vacuum in the condenser. If this be so, the speed may be enhanced, as the wave, that is at present raised in front of the boat, is even less than I have noticed it in front of others of not more than half the speed. The boilers in all the boats of Stevens, as in those of Fulton, are of copper ; and I do not apprehend that, with the highest pressure that can be given them, any danger is to be feared by the passengers. I do not consider that this is the case with any high-pressure boilers. The truth is, that both are liable to burst, from the natural imperfection of materials and work- manship. In the case of a boiler, where the material, suppos- ing the safety-valve to be fastened down, will not bear an internal pressure of more than 8 or 10 pounds to the square inch (marked by from 16 to 20 inches of the steam-gauge), a small vent will discharge the steam, whose expansive force is far from excessive, while the temperature of the water is not such as to augment the volume of steam in any great degree. But when the pressure amounts to 60 or 70 pounds on the inch, and the boiler is proved to bear lOOlbs., as in our high-pres- sure engines, no sooner is a vent given than the whole of the contained water is converted into steam, whicR expands itself with explosive violence. a'*^ I have to note another variation in the engines of the North America from those of Watt : it consists in the suppres 8 Account of Steam-boats sion of the parallel motion. The upper end of the piston-rod bears a cross bar, which works between guides formed of iron plates, screwed down upon upright posts. If nothing be gained in the working of the engine, much is in the fitting it up; for the parallel motion, of all parts of the engine, requires per- haps the most accurate workmanship. The external appearance of the engines of the North Ame- rica is less finished than the better class of English engines. There is, however, no real inferiority. The castings, made at the Westpoint foundery, are excellent ; the boring of the cylinder and air-pump is perfect, and the fitting up. performed under the immediate direction of Mr. Robert L. Stevens, is not to be ex- ceeded. I mention this, because the only specimen of an American steam-boat that has yet reached Europe, was most deficient in all these particulars. That vessel was, however, in every respect, far behind the better class of our steam- boats, even at that distant period (1816), and vastly inferior to those which are now constructed. In our boats intended for the navigation of rivers, several points necessary to be observed in those intended for the ocean, may be omitted. It is, for instance, unnecessary that the engine should work under deck. Hence in all our engines the length of the stroke is greater than those described to me in the English steam-boats ; in the latter, also, the position of boilers, and even of the engine, upon the wheel-guards, would be im- proper, and thus much of the comfort, that this plan affords to the passengers in the North America, would be unattainable. As the steam-boats on the Hudson never make use of sails, and as the waves rarely run high, every other property of a vessel for navigating the ocean, except stability (for instance, the capability of holding close to the wind), may be neglected, in the search for the prow of least resistance. In the steam-boats on Fulton's plan the engine varies from those of Watt, and consequently from those of Ste- vens, in the suppression of the working beam ; the reciprocat- ing rectilineal motion of the piston-rod is changed into circu- lar by means of two connecting rods, attached to a cross bar upon the top of the piston-rod ; these take hold of cranks, or namgating the Hudson Rwer^ '"9 rather ecceniric pins, in wheels upon the axes of the water- wheels. This plan has the disadvantage, that more power is lost by obliquity of action, than when a lever-beam and a connecting rod are used, as in the engine of Watt. When it is used in the body of the vessel, it has the advantage of com- pactness, occupying far less room. In order to give you a proper idea of the velocity of the North America, some other circumstances require to be stated. The distance from New York to Albany has usually been esti- mated at 160 miles ; the post-road between the two places is little less than this, as has been found by a recent measure- ment performed by the post-office department. It is, how- ever, alleged, that the course on the river is not so much, and the surveyor-general of our state has recently published a state- ment of actual surveys on the river, that reduce it to less than 150. These, however, are the shortest possible lines that can be drawn from point to point over the several reaches. As steam-boats cannot follow these lines, but frequently cross the river to stop at landings, I cannot consider the actual distance as less than the first estimate ; I shall, however, assume it to be 154 miles. The average passages of the North America for the last year, including stoppages, were performed in less than twelve hours ; on one occasion in little more than ten. The delay at nine stated landings cannot be taken at less than an hour, which leaves eleven hours for a distance of 154 miles, or 14 miles per hour. As this average is taken from passages both up and down the river, any difference arising from the different rate of the flood and ebb tides, which at some sea- sons is perceptible, and any effect of current whatever, may be left out of view, and fourteen miles per hour be taken as her average speed through the water. # ^ * » * * to l^ruciure and Economy Communication on the Structure and Economy of the Green- land Whale, made at the Royal Institution of Great Britain. By J. Harwood, M.D. F.R.S., Professor of Natural History in the Royal Institution. This discourse was illustrated by means of a veiy extensive series of specimens, &c. There is, perhaps, no part of the history of the animal world which is less generally known^ to those who have not devoted particular attention to Zoology, than that of the Cetacea ; nor certainly is there any, more justly entitled to our considera- tion, from the sublime examples which this tribe affords of Creative wisdom and power. I have, therefore, chosen the Greenland whale for our consideration this evening, because no individual can be expected to offer for our contemplation, more impressive illustrations of the Creator's attributes, than this stupendous piece of animal mechanism ; and, especially, when, not contented with understanding its mere distinctive characters, we regard those conditions in its existence, and those curious modifications in structure, which have adapted its ponderous bulk to a medium, whose specific gravity is so like unto its own, and which afford to its progressive motion the widest geographical range. Although our yearly intercourse with the cetacea during some centuries, has, in modern times, materially extended our knowledge of this gigantic race of beings, we should greatly err in supposing, that their remarkable submarine habits and economy escaped the attention of the observers of antiquity ; and it would be an injustice to the memory of so true a philo- sopher as Aristotle, were I now to omit to mention, that the interest which was excited in his capacious mind by the won- derful characters of cetaceous animals, conducted him to a knowledge of the nature of these creatures, which is calculated greatly to excite the surprise of those naturalists whose oppor- tunities of investigation have even been the most extended. I shall, therefore, notice a few of his observations concerning them, which may prove interesting, from their accuracy, from their antiquity, and from the infant state of natural science at the period in which they were written. of the Greenland WtiaU. II ** There are," he says, ** some animals, which receive and return the water, for the same reason, as others which respire, receive and return the air:'* — here he of course alludes to fishes, which, in the act of respiration, receive the water through the mouth by the expansibility of their fauces, and return it through the beautiful laminated surfaces of their breathing organs, or gills : — '* but there are others," he adds, '' which do so," that is, receive and return the water, *' on account of the nourishment contained within it; and, since they receive their food in water, it is necessary that they should have an organ by which the latter (the water) may be returned or ejected; such animals, therefore, which employ the water in a manner analogous to respiration, have gills; but those san- guineous (warm-blooded) animals, which employ the water on account of the food it contains, have spiracles, or blow-holes.'^ This, it will be observed, is a very interesting distinction be- tween the fishes, and the creatures on which we are now treating, Aristotle's observations on the sense of hearing, and on the voice of these animals, are also highly philosophical ; after showing the incompatibility of voice with the structure of fishes, allowing, however, that many do produce certain sounds, he adds, in regard to the cetacea, ** the dolphin likewise pro- duces a stridulous sound, and murmurs when he comes into the air ; yet not like these fishes, for the sound emitted by the dolphin is voice, since he possesses lungs and an air tube^ although he cannot produce articulate voice ; " and again, he says, in regard to his respiration, ** when caught in nets, he is soon suffocated, in consequence of not respiring, although out of water he lives a long time, murmuring, and making sounds analogous to those of other animals which respire air." After these and many other equally admirable observa-* tions on the part of Aristotle, it appears surprising that the cetaceous animals should ever have been erroneously asso- ciated with fishes in the works of more recent naturalists, from their mere possession of a fish-like form, and the consequent absence of hinder limbs; conditions which are rendered neces- sary by their fish-like progression. Yet not only Ray and Willoughby, but even Linneus, in his earlier works, improperly placed them at the head of that class. 12 Struciufe and Economy Linneus, however, afterwards followed Aristotle, in justly considering them as a tribe of creatures which resembled quadrupeds in disguise ; since, unlike fishes, they not only, as we have seen, breathe the air by means of true lungs, but they closely resemble quadrupeds in much of their general construction, in their manners, in their intelligence, and in the energy of their senses. Their hearts, also, which propel warm, red blood, present no material modification in their structure from those of quadrupeds. Their other viscera somewhat resemble those of the ruminantia, and the size of their brain often even exceeds that of the generality of the mammalia. Being, therefore, mammalia in their economy and their struc- ture, they, in fact, only resemble fishes in inhabiting the same element, and in possessing that external fish-like form, which, being the best adapted for aquatic avocations, necessarily oc- casions differences in the details of their internal structure. The most obvious and striking peculiarities, which first attract our notice in the skeleton of the cetacea, are the enormous size of the head, in the whales ; the almost entire absence of neck ; the length and similarity of the bones of the spine ; their ribs being comparatively few in number ; the shortness of their arms ; and the absence of hinder extremities, an os sacrum, and a true pelvis. Whales have, nevertheless, the ru- diments of the latter, although the two bones which represent it, neither unite before, nor are they attached to the vertebrae. The excessive shortness of their necks, although composed, generally, of only one bone less than the longest neck of a quadruped — as that of the giraffe, for example — renders any separate motion of their heads almost impossible, since the bones of the neck of the whale kind are excessively thin, and immoveably joined together. This, I am disposed to consider as a condition favourable to rapid progression, as that of birds is assisted by the immoveable state of the spine of the back, by which their centre of gravity is rendered less liable to be varied, and their bodies to be thrown out of equilibrium during their rapid flight ; for, did the spine of the back of a bird possess great flexibility, its centre of gravity would be probably changed by every extra effort of either wing ; and to counteract the same tendency, therefore, the necks of whales of the Greenland Whale, l3 and of fishes have, probably, been rendered equally im- moveable. The Greenland whale may, I think, be considered as typical of the order cetacea, a tribe of creatures which, unlike fishes, generally possess only two fins, with the exception of the tail ; and, although some species possess a third fin, on their backs, this latter possesses no bone in its composition ; so beautifully is the analogy preserved between these animals and the rest of the class mammalia to which they belong. When, indeed, we examine the cetacea more critically, we find that these instruments, which present the external appearance of breast fins, by means of which they sustain their equilibrium, and perform gentle motions, owe their present fin-like form simply to the covering with which they are invested ; for, instead of being composed of straight spines, like those of fishes, they conceal bones and muscles, formed very like those of the fore legs of land quadrupeds ; but their hand alone appears ex- ternally, and we see it so enveloped in dense skin, that its fingers have no separate motion. But, as the several bones of the fingers are united together by means of intermediate cartilages instead of capsular ligaments, the fins, or, more strictly, the hands, possess great pliancy and strength, and enable the whale kind to spread them upon their sides, and on the breast; and, as Aristotle observed, in this way, to sustain their young beneath them, closely compressed to their bodies. The fin, or hand of the common whale, is flat, and of much greater proportionate size than in many other cetaceous ani- mals, which extension of the organs of equilibrium appears to have been required to compensate for the more unwieldy construction of the body of the creature. Yet, from the struc- ture of the true and finely organised hand of the ape tribe, to the rude fin of the whale, we perceive no abrupt progres- sion ; since the fore extremities of the amphibious mammalia are precisely intermediate in their formation. These beautiful gradations in organization afford some of the most interesting and apparent exhibitions of intention or design, which are presented to our notice in surveying the animal world ; we may trace the gradual conversion of the hand or fore foot of- the terrestrial quadrupeds into the.fiu of J4 Structure and Economy the whale, most obviously, by commencing with such quad- rupeds as only occasionally frequent the water, in which the ^n or web between the toes is short and imperfect ; and thence proceeding in our examination, successively, through the otters, seals, walrus, the manati, dugongs, to, lastly, the >vhales, in which all the external appearance of a true hand is lost, though, internally, its structure yet identifies the fin with this organ. The tail of a large whale measures about twenty-five feet across. It is composed of several layers of tendinous fibres, strongly matted together within an oily membrane ; which structure imparts to it immense mechanical strength : it is also flattened horizontally, for the purpose of frequently and suddenly forcing the creature to the surface of the water to breathe ; while the tails of fishes, on the contrary, are formed vertically, because their actions being performed chiefly in the depths, they do not require to rise frequently to the surface. But, in the whale, the tail, which is moved by immense de- pressor or flexor muscles, which are inserted into it, and form two large ridges beneath the body, becomes, from its enormous size and power, the most destructive instrument of defence with which any animal has been gifted. When whales are feeding near the surface of the water, this instrument acts with comparatively little force ; for their hands or breast-fins are almost sufficient alone, to modify the movements of their bodies, and thus they swim slowly backwards and forwards, with the mouth generally wide open, and rise at each extre- mity of their short course to breathe. In playing on the surface, they also move in circles, and, occasionally, with the agility of the salmon, they may be seen to elevate their vast bulk almost out of the water ; but, when the violent impulse by the tail, necessary to such an action, is differently directed, they dart like an arrow downwards into unfathomable depths, or, they rapidly extend their progress over vast tracts of the earth's surface. But while we contemplate with surprise the voluntary powers of this creature in its native element, how great is our amaze- ment in regarding the invohmtary muscular efforts of its heart and arterial system ! Mr. Hunter having first informed us, that of the Greenland Whale. 15 l^e found the principal artery of the body to measure n6t less than three feet in circumference, and that it received from ten to fifteen gallons of blood at every pulsation of the heart. Therefore, as Dr. Kidd has observed, if we consider the heart of the whale not to exceed twenty pulsations per minute, at this rate of fifteen gallons received by the artery at every pul- iation, we find, that not less a quantity than four hundred and thirty-two thousand gallons, or eight thousand hogsheads of blood, do literally pass through the heart of a whale during every twenty-four hours of the creature's existence. I may, however, observe, that my friend. Dr. James Alder- son, who has more recently had an opportunity of examining the heart of the same species of whale as the one to which Mr. Hunter alluded, although he found the aorta to be of equal size, supposes that the capacity of the left ventricle was not equal to the reception of more than eight or ten gallons of blood. The heart of the whale, although much flattened, presents, otherwise, no important deviation in its structure from that of terrestrial quadrupeds ; but, like that of other diving mammalia^ and of the seals which I described on a former occasion, it is connected with an enormous development in the arterial and venous systems, in order to preserve it free from the oppres- sion which would otherwise be occasioned by the returning blood ; thereby to extend the intervals between respiration : to this end, the vessels, in various parts of the body, as Mr. Hunter observed, form, by their innumerable tortuous subdivi- sions, vast spongy receptacles ; and, in other situations, the trunks themselves seem to be proportionately much enlarged. The proportionate quantity, also, of blood, in the whale, as in the seal, appears to be far greater than in land animals, which is, indeed, the case in all the aquatic mammalia. I recollect having been surprised by an observation of an old Greenland captain, that the blood of all the animals of high northern latitudes was of a much darker colour than in those of more southern regions ; it being, he remarked, in many, almost black ; he alluded, especially, to the aquatic mammalia, which fell most under his observation, and such is literally the case in them. I have since observed the same fact to obtain 16 Structure and Economy scarcely less in the diving birds ; and it is, perhaps, occasioned by the slow return of the venous blood to the heart, during fre- quent submersion, by which it probably acquires a superabun- dance, or an extra quantity of carbon. In ourselves, it may be added, that the same appearance of the blood is produced, by artificially arresting its progress in the veins ; and that which is slowly drawn from the arm is, on the same principle, much darker than that which flows freely ; a circumstance, even to the present day, often erroneously attributed to a morbid state of that fluid. I shall now endeavour to describe to you another interesting peculiarity in the whale tribes. Beneath their smooth skins, the bodies of these animals are well known to be surrounded by an enormously thick membrane, which contains a prodigious quan- tity of fluid oil. This fluid oil, in like manner, pervades every part of the substance of their bones, which, milike those of quadrupeds, are not hollow, but entirely spongy or cellular. The blubber, or membrane, which contains the oil, varies, in the common whale, in its depth ; it is two feet thick in several situations, especially across the back of the neck ; but it even extends to three feet in thickness in the lip, near the angle of the mouth. It is comparatively the most abundant, and the oil is of the finest quality in young whales ; hence, a sucking whale of nineteen feet long, and fourteen in circumference, has been known to yield six tons of oil, although its whalebone was not one foot in length, and far too short to enable it to catch food. In young whales, also, the blubber is almost white ; in others it is found of a yellowish colour ; and in some, appa- rently from their partaking of a peculiar kind of nourishment, it acquires almost the red appearance of the flesh of the salmon. The blubber may, I think, be considered as a less dense portion of the true skin, consisting, in fact, as I have often seen at Hull, of a strong tendinous membrane, whose fibres inter- weave each other in every direction, and which contain the oil within them ; but, when deprived of the oil, these fibres appear like an irregular network of tendon, differing in the fineness of its texture in different situations ; it being most compact, where itis nearest to the surface of the body, and decreasing in its den- sity as it dips downwards towards the muscles. In striking the of the Greenland Whale, 17 back of the whale, therefore, the harpoon is plunged obliquely into this powerful tendinous network ; which generally holds it so firmly, that I believe it is almost as common for the well- tempered iron to be broken as to be withdrawn ; but, in de- stroying the creature, I may add, that its most mortal part, ■where the lances are afterwards applied, is a little below, and posterior to the origin of the fin, where the heart and the larger vessels are situated. The greatest supply of oil, yielded by a single whale, of which I have been enabled to obtain a well-authenticated account, was the enormous quantity of one hundred and seventeen butts, or about forty-three tons, which was removed from a whale, struck by a person of the name of Pashby, who was liarpooner to the Fanny, whaler, of Hull ; and as the blubber is supposed to weigh about one-third of the whole, we here con- template an animal body weighing no less than one hundred and twenty-nine tons. Another whale, struck by a harpooner, from whom I received the account, yielded ninety-seven butts of blubber, and had whalebone which measured thirteen feet and a half in length, which is the length of the specimens of whalebone now before us ; forty butts of oil, however, are considered a good average produce. The necessity for this wonderful provision in the Greenland whale, to which I have last adverted, the abundance of its oil, is rendered more apparent, when it is known that the real spe- cific gravity of the muscles of this creature is rather greater than that of the muscles of quadrupeds ; but, by means of its oil, so nicely is its body balanced in the surrounding fluid, that it scarcely exceeds the specific gravity of the water. But this prodigious quantity of oil not only thus materially decreases its specific gravity, in which capacity it has been aptly compared to a cork-jacket, but it seems to have been intended as the most perfect of all the various kinds of clothing, with which the mammalia have been gifted ; for, being a very bad conductor away of heat, it thus preserves the warm bodies of the whale kind from becoming chilled by the low temperature of the sur- rounding fluid. In diving birds, it is no less interesting to ob- serve, that the same admirable precaution is had recourse to, JULY— SEPT. 1828. C 18 Structure and Economy though in fishes, whose bodies have naturally a low tempe- rature, this being unnecessary, the oil is differently employed, and serves other interesting purposes in their economy. But the blubber further assists, by its elasticity, in preserving the smoothness and rotundity of the body of the whale kind, which animals, as we see, have not only been deprived of exter- jial ears, or of other external appendages, which would tend to impede their rapid progression, but even the mammae, instead of assuming their usual prominent form, are so flattened and ex- tended beneath the skin as scarcely to elevate the surface ; and on the same principle, the testes never descend from the lumbar region. I must now direct your attention to the very remarkable ex- terior clothing of the whale. It is, in the first place, a curious fact, and one which is, perhaps, peculiar to the tribe, that those parts of the skin which are exterior to the blubber, in a young whale, are twice as thick as they are found to be in the adult, having measured an inch and three quarters in thickness. Now these parts are generally called, from the analogy of their position only, I conceive, the cuticle, and the rete muco- sum ; to preserve which supposed analogy, anatomists are obliged to describe the rete mucosum of the whale as being three quarters of an inch in thickness. But after a careful ex- amination of the recent skin of cetaceous animals, I cannot help believing that there is no analogy whatsoever between this substance called rete mucosum, in whales, and that of terres- trial quadrupeds. It appears to me to be a substance of a na^ ture as peculiar to itself, as that of whalebone, or of ivory ; and it IS here, perhaps, destined to fulfil as peculiar a part in the ani- mal economy, as those substances. It is of a dark colour throughout ; it takes its origin from the outer surface, and, consequently, from the most dense portion of the true skin ; it is of a sub-corneous texture, and consists of a dense congeries of parallel vertical filaments, having a great degree of elasticity. Immediately beneath the inferior surface of this substance, there is a black slimy fluid which is easily separated, and which is, perhaps, the only vestige of rete mucosum ; and this sub- stance is covered, externally, with a thin, smooth, black cuticle, which is easily split into detached horizontal laminae. of the Greenland Whale. 19 The whale, then, has the blubber, which I consider to be the true skin and the cellular membrane united ; a very indistinct rete mucosum ; and, above this, a firm elastic substance, re- sembling a second cuticle, with vertical fibres ; and which is itself covered by a common cuticle, having horizontal laminae. Whether this substance, just noticed, possesses sensation or otherwise, I have not been enabled to determine, but I could perceive no nervous filaments or blood-vessels, to enter its structure, either in that of the whale or sea unicorn, when placed under a high magnifying power ; it is, therefore, probably, in- sensible. The blubber, on the contrary, or the true skin, from its vascular and nervous organization, is, doubtless, highly en- dowed with sensibility. Thus constructed, the skin of the whale is, as before-mentioned, pecuUarly soft, smooth, and flexible; and although, as Mr. Scoresbyhas observed, the pres- sure to which it is liable in the depths of the ocean, is sufficient to force water through the pores of the hardest wood, yet its inherent qualities render it impermeable to the action of that fluid. All these parts of the external clothing are so pervaded with oil, that the latter affords nourishment to several species of small marine animals, which are generally found adhering to the skin ; and in those parts of the seas where whales abound, an oily exudation floats on the surface of the water. On such a scale of dimensions has the Creator been pleased to construct the Greenland whale, that I have myself seen jaw- bones of this animal, which have measured twenty feet in length ; what is called a double oyster-barrel, appears to me to convey the most accurate idea of the size of some of its ver- tebrae. Its tongue, which is of an oval form, is sufficiently large to fill four butts, when cut into pieces, or to weigh two tons ; and to yield one hundred and twenty-six gallons of oil. Of so enormous a size are its lips, and so much do they abound in blubber, that one alone has aftbrded sufficient of the latter to yield four butts, or two tons of pure oil ; and you are aware that the body of this creature acquires from fifty to seventy feet in length. The velocity of motion, possessed by so huge a body as that of the common whale, has always been a source of astonish- ment ; but it is sufficiently obvious, that, having been destined C2 20 Structure and Economy to inhabit depths so profound, and so far removed from the air it breathes, this velocity of motion was a condition necessary to its existence. It, however, very materially increases the danger attendant on its capture ; from the awful accident of a coil of the line of the descending struck whale, entangling itself around any part of the body of the manager of the line, while it is run out ; for, as the animal descends at the rate of from thirteen to fifteen feet per second, in this case, the individual so entangled be- comes immediately dragged to a depth from which he is never able again to rise to the surface ; and thus managers of the fine are sometimes snatched from boats with such instantaneous velocity, as to almost escape the notice of all present. That this species of whale is naturally very timid, is apparent from various circumstances. From the excessive fear into which it is thrown by the infliction of a wound, when reposing on the surface of the sea, it has, on several occasions, been known to descend with such incautious velocity, as to even fracture its massive jaw-bones, and occasion its death, by striking itself against rocks at the bottom. Nevertheless, when urged to resentment, which, as in all other animals, is most readily excited when under the powerful influence of parental attachment, the whale not unfrequently exhibits fatal illustra- tions of its tremendous muscular force. Thus, with the pos- terior half of its body quickly elevated above the water, it is enabled, with its broad semilunar tail, which has been seen to measure twenty-six feet in breadth, and one and a half in thickness, to instantaneously shatter to pieces a strong boat by a single blow. I have been assured by Captain Beadling, on whose word I have great reason fully to rely, that having once wounded a large whale, it instantly elevated its tail high above one of the boats, and struck it with such force as to com- pletely cleave it asunder transversely : the men it contained, by leaping into the water, were nevertheless all fortunately saved by a second boat. There is a poor crippled object now living at Hull, who was shown to me by Dr. Alderson ; he was formerly a boat steerer of the Diana, commanded by Captain Clifford, in which employment, a whale that was struck, ran out all the lines, and at a blow, clove the boat asunder, break- of the Greenland JVhale. 21 ing the thigh, hip, leg, arm, three ribs, and the lower jaw of this poor man ; and, afterwards almost miraculously, dragged the extremity of the boat, in which he lay, seven leagues along the surface of the water, without sinking, within an hour and three quarters; when he was picked up by the Dundee of Dundee. This is, however, evidently, a yet more interesting illustration of the curative efforts of the system, in our own species, than even of the powers of offence in the whale. Another, and, perhaps, still more generally fatal mode of retaliation had recourse to by a wounded whale, especially if it be accompanied by a young one, although fortunately one of less frequent occurrence, consists in the creature tilting furiously, and with impetuous velocity, with the snout, against a boat, by which the latter becomes inevitably shivered to pieces and lost. When in the agonies of death also, by the rolling motion, which a whale often assumes, such blows have frequently been communicated to boats, by its widely extended fins, as to shiver them to pieces. The extreme fidelity of these wonderful animals towards each other, and their affection for their offspring, is almost incredible. So fondly attached are they to the society of their brethren, that many instances are recorded of their assuming a passive floating position, on the surface, after offering much resistance ; as though disdaining to survive the loss of their companions. Thus, when the Cyrus had captured six, out of a herd of seven whales, and they were supported around the vessel on the water, the surviving one rose, and thrust its head amongst its dead brethren, and remained immoveable, close to the vessel, while it was killed. In general, the female is accompanied in her progress by her young one, though, on the contrary, she sometimes wanders very far from it ; and yet, by some unknown impulse, highly calcu , lated to excite our amazement, she has no difficulty in finding it, though perfectly silent, in the vast and trackless ocean, as often as she requires ; and the same may be said of all the cetacea. But further, when her young one is hardest pursued and har- pooned, she supports it under her fin, while she plunges with it for safety into unfathomable depths. A young whale, having been struck by a harpoon from a 22 Structure and Economy Hull vessel, being at the time at some distance from its mother, had run out some length of line, when the latter appeared in sight, and rapidly bent her course towards it. In vain did she use every usual means to induce it to leave the place of danger, while swimming by its side, as far as the line would allow, in circles around the boats, during the space of four hours ; and within this time, on four separate occasions, the parent was observed, when on the surface, to throw one of her fins over the body of the young whale, and to endeavour to drag it away by all the force she possessed ; she, lastly, in this way set off with it, in a straight direction, carrying away ad- ditional line, to the extent of seven hundred and twenty fathoms ; but by that time, the young one became so much ex- hausted from loss of blood, that she necessarily abandoned it to its fate, and herself escaped, by pursuing her progress towards the ice, roaring and spouting with great vehemence ; for here I may observe, that when a whale is struck with a harpoon, or is enraged by the loss of its young, it ejects the water through its spiracles with great force, producing a stridulous kind of roaring, which may be heard the distance of a mile. This species of whale affords to us a sublime instance of contrivance, compensating its total want of teeth. I allude to the hundreds of plates of whalebone, which cover the roof of its mouth ; and which, by their growth, increasing in length, and in breadth, often acquire twelve feet in length, and fifteen inches broad. There have, indeed, been some instances in which whalebone has attained fifteen feet in length ; I believe there is at present a specimen of this kind in the Tower, which was obtained by a London vessel, and, doubtless, from a whale of enormous growth ; since those whales, which afford whalebone of twelve feet, are themselves often more than sixty feet in length. The upper surface of the skull of a whale of this size, measured twenty feet eight inches long ; and the creature itself weighed upwards of a hundred tons. The roots of the two sides of the arch of whalebone, in the mouth of this animal, nearly meet at the top of the roof whence they grow, at the anterior part of the mouth ; but they gradually recede from each other, as they are continued back- wards, till they approach the throat, when they again approxi- of the Greenland Whale, J3 mate. This substance, called whalebone, which thus supplies the place of teeth, consists of a peculiar kind of horn. Its plates differ in their length and strength, in different parts of the mouth, but the outer row of plates are by far the strongest and the longest, especially those which are midway between the throat and the snout. Internally, supposing ourselves to be placed beneath the roof, and regarding it from below, from the lower edges of the outer plates, (those which they inclose becoming shorter and shorter, as their origin is more internal, or nearer the centre of the roof,) we see the lower edges of all uniting to form one inclining plane, extending obliquely up- wards to the roof. And, as the fibres of every plate are loose and separate at its inferior edge, forming a deep pendent fringe, by the gradual splitting away of its substance in propor- tion as it is used, we perceive the entire vaulted sides of the roof of the mouth to be, in fact, by these means, deeply lined with a clothing of thick and coarse hair, whence the ancients gave to this species of whale the name of Mysticetus. Now, beneath this vault of hair, lies the enormous tongue of the whale, and exterior to it, is the immensely high lower lip, which, when the jaws are closed, shuts up over all externally to the very origin of the whalebone above, so as to entirely conceal it from view. By means also of this formation of the lip, and the circumstance of the upper jaw shutting into a car- tilaginous groove at the extremity of the lower one, the most perfect valve is formed, which any pressure from without, only tends to render more secure from the ingress of the water. The fringe, which I before mentioned, produced by the whale^ bone, (as it is constantly and gradually extending itself in length, by the growth of the whalebone behind it, in proportion as it is worn away,) is thus always in a proper state of adapta- tion to the marvellous economy of the creature ; for the most curious part of this beautiful mechanism is the net or sieve which it thus forms ; an instrument which has been granted to this largest of creatures, for the purpose of straining or separating its minute prey from the body of water necessa- rily taken into the mouth with it, in feeding. For, in this whale, the mouth is of such enormous proportions, as to receive at once, even tons of water, and yet of such wonderful per- Zi On the Inland Navigation of fection is its filtering mechanism through these hair-hke fila- ments, that it rarely allows the escape of the nourishing par- ticles diftused therein, although they be no larger than peas; its food consisting chiefly of small medusae, Crustacea, and zoophytes. (To be continued.) On the Inland JS'avigatlon of the United States of America, PART II. [Communicated by the Author. Continued from the Number for January, 1828, Art. I.] The success that attended the execution of the Western Canal of the state of New York, drew the attention of the inhabitants of Philadelphia and Baltimore to the subject of Inland Navi- gation, It was soon perceived that the trade of both these cities was affected by the diversion of a considerable part of the traffic of the country west of the mountains, to that new and more convenient channel. Each of these cities, therefore, entered eagerly into the search for channels equally advan- tageous ; but these investigations have not been attended with any consequences of important value. From Philadelphia three several routes have been examined ; in one of these the summit is impracticable for want of a supply of water ; the others involve an expense far beyond any probable return, in consequence of the number of locks that would be required to surmount the ridges. Hence it may be asserted that there is little probability of the opening of an entire canal from this city to the Ohio, or Lake Erie, although there is a strong probabihty that a mixed system of canals and railways will be successful. To this the legislature of the state have very recently directed their attention, and have made large appropriations for it. Two navigations, that will form import- ant parts of such a system, have actually been completed. Philadelphia lies between two rivers, the Delaware and the Schuylkill, which approach at that point to a distance less than two miles. The former is navigable for the largest ships, the latter for vessels of 100 tons. Immediately above the city the Schuylkill is interrupted by falls, and although from its volume the United States of America. 12& of water it would rank in a high place among European rivers, the nature of the country is such, that interruptions of a similar character are frequent throughout its whole course. As many parts of the river are bold and deep, the Schuylkill navigation has been effected by using the bed in such places, and con- necting them by canals and lateral cuts. To deepen the river and check its current, twenty-eight wears have been thrown across it. The whole navigation amounts to 108 miles, 46 of^ which lie in the ancient bed of the river, and the remaining 62 in the artificial channels. Besides 28 guard-locks at the wears, there are 92 locks overcoming a fall of 588 feet. So that this comparatively short navigation has a greater change of level than the Erie canal of the state of New York. The grand object of this navigation was to form a water communi- cation with a vast coal field, of which we shall have occasion to speak hereafter. At a distance of 58 miles from Philadelphia (measured on the Schuylkill navigation,) is situated the borough of Reading. From this a canal, called the Unioriy has been completed to the Susquehannah river. It is 71 miles in length. The summit level is 300 feet above the Schuylkill, and 210 feet above the Susquehannah. In the plan of the canal a difficulty was found in obtaining a supply of water for the summit level. This has been obviated by raising the waters of the Swatura by machinery, at such seasons as the other sources are usually scanty, and this will no doubt be effectual. An important improvement in the structure of the locks of this canal was planned and carried into effect, by the very intelligent and skilful engineer (Mr. C. White) who super- intended its construction. This improvement consists in the suppression of the breast wall, and making the upper gate nearly of the same depth as the lower one. The bottom of the lock has a slight slope, and the upper reach of the canal is gradually deepened until its bottom reaches the same level as that of the lower. As the breast wall is the weakest part of a lock, and adds considerably to the expense of construction, while it involves, in addition, the cost and inconvenience of lateral culverts in the walls, this improvement may be con- sidered as very important ; it is, in truth, the only change of W On the Inland Navigation of real value that has been introduced into the structure of locks, since the time of the opening of the canal of Languedoc. We have seen a proposal for a similar change in the form of locks, made by a French engineer ; and although he is, doubtless, no plagiarist, still it is proper to state that Mr. White's locks were not only planned, but built and in actual use before the French publication made its appearance. The Susquehannah, we have stated, in the former paper on this subject, to be full of rapids and other obstructions, from the time it enters the state of Pennsylvania. It is prac- ticable as a descending navigation for arks in times of floods, and an attempt was made, some years since, to mount against its current by means of a steam-boat. Although this vessel did mount the river, it appears doubtful whether the experi- ment will be followed by any useful results ; for it would be impossible to convey in this manner any heavy lading. There is, however, little doubt that a canal might be made in the valley of the Susquehannah, as far as its junction with the Tioga branch. The latter, running altogether on the western side of the great ridges of mountains, might readily be ren- dered navigable ; and plans have been proposed, to connect it with the Gennesse River, and with the Seneca Lake, in the state of New York; by either of these, it would come into communication with the Erie canal, and thus with the lake of that name. We consider this to be the best route by which Philadelphia can be brought by canals into competition with New York for the trade of the western country, unless some successful sub- stitute be found for locks in inland navigation. It is, however, far more circuitous and distant than the New York route, but it has the important advantage, at certain seasons, of being earlier clear of ice, and closing later than the New York canals. It is probable, that some means may be found of lessening the distance, and for this purpose a canal route has been examined directly from Philadelphia to Harrisburgh, on the Susquehannah. The legislature of Pennsylvania has recently adopted a great and general system of internal improvement by canals and rail-ways ; and is thus the second state of the union that has the United States of America, 2t followed the example of New York, in appropriating its re- venues and credit to great public works. The debt contracted for such objects stands upon a very different footing from that which arises from warlike enterprises. While the latter im- poverish a country, and diminish the means of liquidating the expenditure to which they give rise, the former increase and extend the sources of wealth, and provide ample means for the repayment of the cost of their construction. The chance of the city of Baltimore being able to effect an advantageous and direct line of water communication with the states west of the mountains, is less than Philadelphia. It is, however, better situated to avail itself of the descending trade of the Susquehannah, or of any improvements made in the bed, or the valley of that river. Failing in the hopes of a canal, a plan for a rail-way from Baltimore to the Ohio River has been set on foot ; the enterprise has been taken up by a company, chartered by the several states through which it is to pass, and the whole of the stock subscribed. It yet remains, however, to be ascertained by experience, whether a rail-way can ever be made to compete on equal terms with a canal navigation. The states of Maryland and Virginia have earnestly sought a mode of communication with the Ohio, and by its branch, the Allegany, with Lake Erie, through the valley of the Potomac. In this the general government has also taken an interest, and a route has been carefully surveyed by officers of the United States Corps of Engineers. This investigation has shown that a summit level can only be obtained, by deep excavation, or by a tunnel of nearly six miles in length, and that this summit will be elevated 2486 feet above the tide water of the Potomac, and 1730 above the Ohio at Pittsburgh. We therefore consider ourselves warranted in saying, that although certainly practicable, it will, if locks be used upon it;, involve an expense far beyond any that can be reimbursed by its revenue, or even by its public advantage. Notwithstanding this, a bill, authorizing a subscription to a company formed for making this canal, has passed the house of representatives, and will probably become a la>v. Within the state of Virginia, the sources of James River, which empties itself into the 28 On the Inland Navigation of Chesapeake, and of the Kenhaway, that falls into the Ohio, approach near to each other. James River is navigable for vessels of 125 tons as far as Richmond, the capital of the state. Partial improvements of the bed of this stream were made many years since, by a chartered company, and these are connected with the lower parts by a canal and fifteen locks, in the vicinity of Richmond. These have however been of so little value, that it is now proposed to make a separate canal, up the valley of the James River, and of its branch called Jackson's River. The mountains here appear to form an insuperable barrier to artificial navigation, and hence a rail- way must be resorted to, in order to convey the trade to the Kenhaway River. This last, it is reported, may be made navigable by wears and sluices. Much anxiety has been ma- nifested by the intelligent population of this state, to press forward these improvements, and an engineer of high repu- tation, a pupil of the French Polytechnic school, has been employed, under the direction of a board of public works. We shall here close our accounts of those canals, whether executed or projected, that are intended to form a communica- tion between the sea-bord and the states west of the Allegany mountains. Those which we have mentioned are, in fact, all from which any important consequences are to be anticipated. We proceed to notice the artificial navigations, the objects of which are more confined. These we shall con- sider in the order of the states, beginning at the north-eastern frontier, and proceeding south, and shall confine ourselves to those which are actually completed, or in a state that promises speedy completion, unless in cases where the impor- tance of the enterprise, or some other cause of interest, shall render them worthy of remark. In the new state of Maine no work of any importance has been commenced, or even projected. In New Hampshire, it has been proposed to unite the tide waters of the Piscatawny at Portsmouth, with the upper part of the Merrimack through Lake Winnesipiogee. This latter river has been rendered navigable for boats, as far as the confluence of Baker's river, 130 miles from the sea. Of this distance, twenty miles, as far as Haverhill in Massachusets, are navigable for ships. the United States of America, 21) In the state of Massachusets, the Middlesex canals are by far the most important artificial navigation. This work was commenced in the year 1793, under the direction of Mr. Weston, an English engineer, and in 1804 was opened for the passage of vessels. The canal enters the Charles river at the town of Charleston immediately opposite the city of Boston. From the tide it rises one hundred and four feet to the summit level, and descends thence thirty- two feet to the Merrimt^ck. These changes of level are effected by twenty locks. But one other artificial navigation has been actually com- menced in this state : this is a canal from the town of Worcester to Providence in the state of Rhode Island. The most important advantage to be anticipated from the comple- tion of this canal is the conveyance of coal, which is said to exist in abundance at Worcester, to a port whence it may be shipped. Connecticut is without any other canals than those men- tioned in speaking of the system extending parallel to the coast : and in Vermont, although various projects have been entertained, no canal has been actually commenced. As New York was the state that furnished the first great example to the rest of what might be done by a well-combined system of artificial navigation ; so this large and' populous state has been more prolific than any other in the Union. Surveys of no fewer than sixteen, were ordered to be performed at the expense of the state by the Legislature at its session of 1826. Three of these routes have been more recently pressed upon the attention of the public ; and to them we shall confine ourselves. The counties bordering upon the St. Lawrence possess a fertile soil, and were not behind any part of the state of New York in prospects of wealth and population, so long as the natural outlet of the St. Lawrence was open for the export of their pro- duce. They even competed with the western counties, on more than equal terms, for the swarms of the New England hive, until the opening of the Erie canal. Since that period, they have been upon the decline ; the tide of population is no longer directed towards them ; and even those families that have settled, fre- quently leave them in pursuit of a more advantageous seat. So short, however, is the distance from the Erie canal, that ai^ 99 On the Inland Navigation of artificial navigation would speedily restore the equilibrium between these counties in the valley of the St. Lawrence and those in the west. An act has passed the Legislature of the state of New York, authorizing the formation of a chartered company to effect this communication, and the commissioners therein appointed are engaged in repeating and extending the original surveys with a view to attain exact estimates of the cost. Some of the natural circumstances are extremely favour- able to the formation of this canal ; the supply of water from the Black River, a tributary of Lake Ontario, and from Canada Creek, a branch of the Mohawk, is exuberant ; the former stream is itself navigable for boats for a considerable part of the distance, and requires little more than a towing path (unless steam-boats should be found more advantageous) to make it a canal ; and all the necessary materials are to be found in abundance. On the other hand, the elevation of the summit is very great, the whole amount of rise and fall being nearly sixteen hundred feet. Such, however, is the fertility of the country that will contribute the trade, and such the value of its pine forests which will instantly furnish a profitable article of commerce, that we feel assured that, even if locks be em- ployed to overcome the elevation, a large interest will accrue upon the investment of the capital necessary to complete this navigation ; while, if the resources of mechanics furnish any cheaper mode of obtaining a change of level, it must be pro- digiously lucrative. The success of the Erie canal is in truth an earnest that this cannot fail to be not only useful to the country, but profitable to those who execute it. It is however yet questionable whether it will be possible to obtain capital for the accomplishment of this important undertaking. The state has in some measure decided that it will not for some years to come undertake any new enterprises ; the country this canal is intended to benefit, is, from the causes we have stated, much impoverished ; such too is the demand for capi- tal in other parts of the States, to be employed in the innume- rable branches of industry which the progress of internal im- provement has called into existence, that little inducement exists to divert it to the accomplishment of enterprises of this character. Surplus wealth, beyond what is invested in lands the United States of America, 31 and buildings, or is engrossed in manufactures and commerce, hardly exists in the United States, except in the great cities, and even there it has the facility of being invested in the local banks and other monied institutions, that have hitherto ab- sorbed the capitals of the few who are not engaged in active business. Those who are willing to incur the risks of trade look for larger profits than a canal is likely to afford ; those who seek a secure income without encountering the vicissitudes of commerce, have hitherto preferred the stock of banking insti- tutions for the investment of their capital. Hence in many projects for internal improvements, the privilege of banking has been attached to the charter for canals, as a bait for subscrip- tions. It is hardly necessary to state that this heterogeneous asso- ciation has not been, generally speaking, a fortunate one. The profits of banking are gradually falling, however, and must soon become so small as to compel the increasing permanent capital to be invested in enterprises of this nature. But, in the mean time, we cannot help wondering, that the capitalists of Europe, who have been for some years past searching in all directions for new modes of investment, should not have turned their attention this way. So little however does the character of these enterprises, or the resources and good faith of the states of the American confederacy, appear to be understood in the money markets of Europe, that we are inclined to believe that the most advantageously situated canal route would fail in obtaining subscribers, although South American mining stock would be eagerly taken up ; and we know, that, at a time when Greek, Columbian, and even Poyais loans were sought with avidity, the state of Ohio could not obtain a loan for the execution of the important work we spoke of in the former part of this essay. The money for the last was indeed readily obtained in the United States, but at a rate of interest higher than is usually paid in Europe. There is, no doubt, great cau- tion to be employed in determining between the different pro- jects of canals with which the United States are teeming ; nor are all the states equally capable of paying the interest of, or redeeming loans ; but the discrimination may be effected by the exertion of ordinary prudence. The canal in question, for instance, is one whose cost can be ascertained within a trifle, 32 On the Inland Navigation of in consequence of the experience attained by the engineers of the state of New York in constructions of the kind ; its revenue is susceptible of ready estimate, and it is situated in a state that has attained, by the strict performance of all its engage- ments, the highest character for good faith and ability to com- ply with its contracts. The second of the projects that has been recently agitated in the state of New York is the Chenango canal. This derives its name from a branch of the Susquehannah river, and is intended to form a communication between that stream and the Erie canal. A bill to construct this at the expense of the state failed of becoming a law by a few votes. A charter of the most full and liberal character might no doubt be obtained for its construction by a company ; but we are not aware of its possessing equal advantages, or a probability of as great a revenue, as the one we have just spoken of. The third of these routes lies between the head of Cayuga Lake and the Susquehannah at Oswego. Difficulties, arising from a scarcity of water and the height of the intervening land, have caused the plan of a canal in this direction to merge in that of a railway. A company has been chartered to carry this into effect, and will probably go into successful operation. Besides these embryo projects, two canals have been actually executed at the expense of the state ; the first forms a communication between the Erie canal and Lake On- tario, by means of the Oswego river ; the second between the same canal and the Seneca lake. One private enterprise of great extent and importance has been nearly completed in the State of New York ; this is the Delaware and Hudson canal. It enters the latter river near the mouth of the Wallhill at the town of Kingston, and extends in a south western direction, through the vallies of the Rondont and Nevisink, until within a short distance of the confluence of the latter with the Delaware, and for a distance of 64 miles. The ascent from the Hudson to the summit level is 535 feet, and the descent to the Delaware 80 feet. From the valley of the Nevisink it rises through that of the Delaware, and near its margin for the distance of 17 miles, and to a height of 148 feet. Here it crosses that river and enters the valley of the the United States of America, 33 Sackawasen, along which it is to be carried as far as the forks of the Dyeberry, about 20 miles. The canal was opened ia April 1828 from the Delaware to the Hudson, the remainder is in a state of rapid progress towards completion. From the termination of the canal, a railway has been laid out, rising about 500 feet to a gap in the Moosick mountain, whence it descends 800 feet to the valley of the Sachawannock, a branch of the Susquehannah. At this point is an immense bed of coal, a portion of the great anthracite formation of Pennsylvania. The great object, indeed, of this canal is to bring a supply of this valuable fuel to the city of New York, and to those districts on the Hudson in which wood has become scarce. As the coal of this region has been the source of a variety of projects of inland navigation, besides the canal we have just mentioned, it will be essential to the complete illustration of our subject, that we should describe this formation. It may be traced from a point in Dauphin county, Penn- sylvania, about fifteen miles north of Harrisburgh, the seat of the state-government. It thence extends about E. N. E. through the whole length of Schuylkill county, and incloses the sources of the river of that name. On the borders of Schuylkill and North Hampton counties it turns suddenly to the north, and proceeds in that direction, until it reaches the Susquehannah river, in the vale of Wyoming, when it spreads out on both banks of the river, and includes the whole valley. Here the formation resumes its original course, or one more nearly N.E., and when the course of the river abandons that direction, the coal can still be traced pursuing that azimuth, up the valley of the Sachawannock ; along this it extends to the very source of that stream ; and the last mine that has been opened is at Belmont in Wayne county, the north-eastern corner of the state of Pennsylvania. The whole length of this formation is about 1 10 miles, the breadth from four to eight miles. According to the investigations of the late Mr. Cist, of Wilkesbarre, the coal extends beneath the whole of this region, and is in many places from twelve to thirty feet in thickness. The supply is, in truth, vast beyond calculation. The general character of the coal of this formation is what is called by mineralogists anthracite^ and is similar to that of the JULY— SEPT. 1828. D 34 On the Inland Navigation of Kilkenny coal of Ireland, burning without smoke. Its pro- perties as a fuel are, however, various, according to the situation and circumstances under which it is found. In some places it is dry, and composed of carbon nearly pure, the earthy matter amounting to little more than five per cent., and there being no other impurity. In others it passes towards the character of the adjacent carboniferous shale, and then leaves much ashes after its combustion. In others, again, it is saturated with water. This last variety burns much more freely than any other, and, when dug from beneath water, or from mines loaded with that liquid, it is found to assume a resplendent pavonine hue. The flame that attends its com- bustion is no doubt due to the decomposition of the water with which it is charged, while that found in dry situations burns away without emitting any gas heated so far as to become luminous. In the one case, it forms a pleasant and bright fuel for the open grate, while in the other it burns only in furnaces possessing a great draught; but it then furnishes the most durable and intense heat of any fossil substance. Many of the mines furnish specimens of fossil charcoal, in •which the ligneous structure is as marked as in that recently prepared from growing timber ; and thus is afforded another link in the evidence, that all coal is of vegetable origin. In the shale and sandstone that accompany the coal, great quan- tities of vegetable impressions are also found. These appear to be identical, in genera and species, with those which accom- pany the bituminous coal of England. The shale that overlies the coal has a very peculiar character, containing much car- bon, but no bitumen, and may hence form a new mineralo- gical species, carboniferous shale. This great coal field has not hitherto been traced into the state of New York. Identity of geological position would, however, warrant the belief, that its continuation, or a separate but analogous formation, will be found on the western side of the Catskill mountains ; and, in corroboration of this belief, it may be stated, that the writer of this article found coal in place, near the Little Falls of the Mohawk River, on the western side of the mountain through which that stream forces its way, and which is a continuation of the great Allegany ridge, of which Moosick Mountains and the Catskills are parts. the United States of America, 90^ The search for coal in this direction has, however, been re- tarded, in consequence of an erroneous impression that has been given of the character of the rock at the Little Falls. In the published geological survey of the New York canal, it has been classed as a primitive rock, while it is, in fact, a coarse-grained sandstone, retaining, indeed, the crystalline character of its parts in an uncommon degree, but readily distinguished, by the looseness of its aggregation, from the family of gneiss. It is probably similar to the sandstone used in many of the edi- fices of Thebes in Egypt, which was long mistaken for gra- nite, although more close examination has shown that the latter material is only used in a few vast monoliths, and never as the material of buildings. As we have been led, in order to render the objects of several canals obvious, to mention this coal formation, it may not be irrelevant to state, that in the state of Pennsylvania there are other extensive coal fields ; one of these has been lately discovered near the Tioga branch of the Susquehannah river ; another has long been worked in the vici- nity of Pittsburgh, at the confluence of the Allegany and Mo- nongahela ; both of these are bituminous in their characters. Coal of the same species abounds in many places on the banks of the Ohio river, in the states of Ohio and Kentucky. j^ As cultivation increases, and the wood is more frequently cut, not only does the space occupied by growing timber de- crease in the Atlantic States, but the power of reproduction appears to diminish ; the demand at the same time becomes greater, in consequence of the greater number of persons to be supplied, and the extension of manufacturing industry. Hence, in the great cities of the sea coast of the United States, fuel has for many years borne a price far greater in proportion than any other necessary of life. With the exception of a small dis- trict in Virginia, and beds of anthracite of very inferior quality in Rhode Island, and at Worcester in Massachusets, no coal has been found to the eastward of the first or primitive range of mountains. Hence a cheap and abundant supply of coal may be considered as almost essential to the continuance of the prosperity that has hitherto attended the progress of that portion of the American Union. The discovery of the great field of anthracite coal in Pennsylvania has hence been consi- D 2 9^J On the Inland Navigation of dered as likely to be attended with the most important conse- quences ; while the formation of channels by which it could be readily conveyed to the markets, appeared to offer the most advantageous prospects for a profitable investment of capital. The coal of the vale of Wyoming may be conveyed by the Susquehannah to the tide-waters of the Chesapeake Bay. But that river does not at present permit an ascending naviga- tion ; and the supply, although cheap, is limited to what can be furnished by the species of vessel called in America arJcs. These vessels, rudely built of hewn logs, are broken up at their place of destination, and sold as timber, or even as fuel. If by no means costly, the quantity of them that can be prepared in a season is small. A similar attempt was made on the waters of the Lehigh, to supply the city of Philadelphia, but was, for the reason we have stated^ found inadequate to the demand. The Schuylkill navigation, described in the early part of this paper, was undertaken to open a more certain com- munication with these mines, and has been successful so far as Philadelphia is concerned ; much coal has been shipped by sea to New York. But as a great part of the coal field is not more distant from the latter city than it is from the former, and as New York is likely to be a much greater consumer of this fuel, more direct modes of communication have been sought between it and the mines. The only one that is likely to be very speedily completed is the Delaware and Hudson canal ; and such is the facility it will offer for the transportation of coal, that the best estimates appear to prove, that it may be delivered on the bank of the Hudson at so low a price, as not only to supply the demand of the city of New York, but even to supersede wood as fuel, in the very districts where it is now cut for the market of that metropolis. Wood is in truth so bulky, and requires so much labour to convey it to the place where it is used, that the farmers of those parts of the country to which coal can be carried by water, are already beginning to purchase coal, and abandoning the cutting of the wood that grows upon their own lands. The Delaware and Hudson canal, to which we now return, was commenced at a period when the frauds and misrepresen- tations that marked the era of joint stock companies in the United States of America. dH England, had extended to America, with a portion of the same mad spirit of speculation. But while various other companies were managed with a reference merely to the elevation of the price of their stock, this canal company was distinguished, in the most honourable manner, by a direct and faithful determination to carry into effect the great objects of their charter. It hence enjoys the highest cha- racter and credit ; and when it became necessary to raise a further capital, to extend the line of communication beyond the point at which the original estimates ceased, the state was in- duced to pledge its good faith for the redemption of a loan of half a million of dollars. Such favour this company justly merited, from the honour and fidelity with which its business was conducted. We shall close the present paper by mentioning another pro- ject for a communication with the coal region ; the route of which lies partly in the state of New York. It was intended to pass in a direction nearly parallel to the Delaware and Hud- son canal, from the mouth of the Pequest, a branch of the Delaware in Sussex county of New Jersey, to the Hudson in the vicinityof the village of Newburgh. Although the route has been surveyed, and found practicable by a very intelligent engi- neer, and a charter granted by the states of New York and New Jersey, no step has been taken towards its construction. It would afford, however, as convenient a mode of reaching the coal mines as the Delaware and Hudson canal, and has the advantage of entering the Hudson nearly forty miles nearer to New York. In the former part of this essay, we paid what we felt to be a merited tribute of praise to the then governor of the state of New York, De Witt Clinton. Even before that paper reached England, that great public benefactor of the United States had ceased to live. He has left a space in the public councils of his country, that will not soon again be filled by one equally zealous for the improvement of his country, or equally fearless in promoting the facilities of internal commu- nication, at the risk of the loss of political consequence, and popular favour. 38 On Malaria on Ship-hoard, By Dr. Mac CuUoch. If in the former papers on Malaria, to which you gave admis- sion in your Journal, I took occasion to notice the production of this poisonous substance in ships, I submit to your judgment as to the propriety of entering on this particular branch of that question in more detail : partly on account of its great import- ance, partly also because of the very persevering mistakes which appear to have been committed on this point, and still more, as you justly remark, because that which was likely to have been passed with little notice in a general sketch of the entire subject, is more likely to attract the attention of those whom it may concern, when thus separated under a specific title, and treated somewhat more fully than was formerly admissible. If it has not been an unvarying opinion that the fevers occurring in ships, and particularly those breaking out at sea, are of a contagious nature, or appertaining to Typhus, (to use a term now become popular,) I should find some difficulty, at this moment, in producing any opinions to prove that they were thought to appertain to the Remittent, or were fevers produced by miasma or malaria, and not by contagion ; except at least in these very unquestionable, or unquestioned, cases, where the disease attacks the patient in a tropical climate, or other analogous country, in consequence of communication with the shore. On the contrary, I should, I believe, be safe in saying, that almost every fever, perhaps even every remarkable occurrence of this nature in a ship, has been viewed as an example of contagious fever, or as a true Typhus ; while the treatment has of course been modified by that opinion. Nor is this matter of surprise. I have shown in the Essay on Malaria, that throughout Britain generally this error has been extremely prevalent, for at least many years : while it might be curious to investigate the causes, whence it has arisen that we, of this day, had, on this subject, forgotten the knowledge of our predecessors, the Sydenhams and Lobbs, though it is an inquiry in which I ought not to indulge in this Dr. Mac Gulloch on Malaria on Ship-board. 39 place. The fact, nevertheless, is such. The true remittent fever is not indeed unmarked or unknown : but it is most cer- tain that the very great majority of cases are termed, as they are considered, typhus ; while if navy practitioners take pre- cautions against contagion under those occurrences, it has been very common among others to express surprise that the disease had not been communicated to the attendants. Sometimes, indeed, the practitioner imagines that his precaution has been the cause of stopping this anticipated but imaginary process ; but it has also very often happened that where, from situation, from exposure to a common exciting cause, in an active and present malaria, many persons in one house have suffered, simultaneously, or rather in succession, the fever has been pronounced as propagated from one individual to another through a large family, when the truth has been that each was subjected to his own distinct marsh fever from a common ex- posure : and it is this which explains also that which has so often been a cause of surprise ; namely, the occurrence of single cases of fever, in a numerous family, or in a populous neighbourhood, while perhaps no precautions have been taken against its propagation ; just as it accounts for the innumerable instances in which the so called typhus fevers, received into hospitals, have not spread. Such fevers could not have been propagated, because they were not contagious, or were not typhus fever; while I need scarcely say to Physicians how very easy it is to mistake the continuous marsh fever for the true typhus, or, equally, that in which the remissions are slightly marked ; and very particularly in the ordinary routine of practice, often hurried : an error, also, the more easy, should the prejudices, habits, and general impression of the practi- tioner on this subject have given his mind a general bias to this belief, the belief in contagion or in contagious fever as a common, or as the more common disease. And that this has been a recent belief in England, or rather that it has been an opinion gradually spreading or accumu- lating for many years, must be well known to all observing physicians, while it would not be without interest to inquire how much it has depended on the recently augmented use of the term typhus, and its even popular adoption by the multi- 40 Dr. Mac Culloch on Malaria on Ship-board, tude at large. The influence of terms forms one of the most curious departments of the history of the human mind, and is the foundation of more fallacies than all else which that history can furnish. As long as the term in use was fever, simply, the disease might have been any fever; and it was then the busi- ness of the physician to ascertain what it was, whether it was a marsh fever or a contagious one. But the term typhus once adopted, became the substitute for examination and reasoning alike, as it became also the rule of practice : the association of ideas led necessarily to contagion ; and hence unquestionably one leading cause of the rapid growth and progress of this error : an error which will not soon be eradicated, and may not possibly be entirely corrected until some change of the general, and particularly of the popular nomenclature takes place. As a proof of this popular and general error, it is sufficient to open any monthly journal or inspect any newspaper, where we read currently of the prevalence of typhus " in this month," August and September, for example, and how " in this month," November, the number of cases is gradually diminishing. And these are the reports of physicians holding public situations in hospitals, from whom, if from any, we are entitled to expect more correct notions ; particularly when they set up to be the recorders of medical statistics, to descend, possibly, to posterity, and corrupt the entire history of medicine. If it is from such authorities as these that Heberden and others have drawn their averages and deductions, we may well be cautious how we reason on them. I am aware that more correct notions have for some little time begun to take place of this extensive error ; but physi- cians know as well as I do that they are still very limited — so limited, that among men of any reputation, it would not be very difficult to point out the individual. They know, too, that such correct views, although promulgated by teachers, have very little effect on the general opinion and practice at present; and it is such teachers who will best know that in the Essay on Malaria, and in that on Marsh Fever, I have not overrated either the error or the evil, strongly as I may have pointed it out. But if I have thus pointed out this most common and widely Dr. Mac Culloch on Malaria on Ship-board, 41 extended mistake, I ought to caution any reader of this paper from supposing that the writer of it is one of those who doubt or deny the existence of a typhus, or a truly contagious fever. It is difficult, indeed, to conceive how such a doctrine could have been promulgated by any one acquainted with practical medicine, or with the history of medicine : yet temper produces strange phenomena in human society ; while the not uncommon tendency of mankind (o fly off" suddenly into opposite extremes, and not a little the love of paradox, added perhaps occasion- ally to a little desire for notoriety through whatever means, may perhaps serve to explain this recent aberration of opinions. It ought almost to be unnecessary to say how important it is to distinguish between these two kinds of fever ; the contagious and the non-contagious, typhus and marsh fever. And since a clear idea of this subject, as far as that can be conveyed in a paper of this popular character, is essentially fundamental to the special object of this brief essay, I must be permitted to enlarge a little on these general views ; confining myself also as much as possible to that which, whether as matter of doctrine, or matter of practice and utility, can be rendered ap- prehensible to general readers. Such readers ought, therefore, to understand that there are two fevers, of characters essentially distinct, if often very much resembling each other in their symptoms, or general appear- ances, progress, and effects ; and that there are but two, — as I hope can be proved to the satisfaction of medical readers : all the eruptive fevers, together with all the symptomatic ones, or those which attend local diseases, being of course excluded : — two simple fevers ; and one of these being the produce of vegetable decomposition or malaria, including consequently all marsh fevers, while the other, originating it is not always ex- actly apparent how, can be communicated from one person to another, which the former cannot. And this last is typhus ; including many varieties, from a very slender disease to the most mortal jail-fever or putrid fever: while, under the former, are ranked every variety of ague or intermittent, together with remittent fevers, which are often as persistent or continuous as typhus or contagious fever, and often also assume the same character of virulence or putrefaction, with a course as short 42 -Dr. Mac Culloch on Malaria on Ship-board. and as destructive ; but the essential distinction always con-* tinues. These cannot be communicated from one individual to another. Thus simply stated, it might be supposed by general readers that nothing could be more easy than to make the distinction in practice. Yet the fact has proved far otherwise, and even in much graver cases than the fevers of our own country, or even the fevers of ships ; from causes, some of which I must allow my own profession to assign, as they would scarcely thank me for the attempt. To these readers, however, it will be interesting to know that on this have been founded all the confusion and all the disputes which so long occupied the world, and still occupy it occasionally, respecting the yellow fevers of the West Indies and of America, the fevers of Gibraltar and Cadiz, and the more recent ones of Barcelona and Alicante : while the confusion, the inconveniences, and the terrific mortalities which have resulted from these errors, I could not here undertake to speak of, without trespassing on at least the bounds of this essay, if not so very much upon its objects. Generally, however, I may venture to say, that as severe typhus and severe marsh fevers often put on the same aspect, so while the peculiar biliary affections caused by heat are common or general in hot climates, it has happened that these, occurring in each kind or class of fever, and forming an obvious symptom, as also giving rise to a popular term, have caused the name Yellow Fever to be applied indiscriminately to both. Thus there has been a yellow fever which was con- tagious, and a yellow fever which was not contagious, or a marsh fever ; this last being the common endemic of the West Indies and other tropical climates, as of Spain, while the former has been a contagious disease, casually arising, or imported in ships, and propagated in the usual manner. That the yellow fever and the mortal fever of Gibraltar proved of this nature, and that, in the last case in particular, this contagious '^ yellow" fever had been mistaken for the non-contagious, or marsh " yellow" fever, with mortal consequences of the most tremendous amount, will form a sufficient illustration to ordi- nary readers, as to this particular error ; while it will be a suffi- cient example also of the exactly reverse error, that the fever Dr. Mac CuUoch on Malaria on Ship-board. 43 of Alicante, which was the non-contagious, or marsh, *' yellow'* fever, was mistaken, reversely, for the contagious one, and managed accordingly, with very inconvenient results, if not with similarly mortal ones. And that the readers for whom I am here writing may ap- prehend generally what the consequences of these mistakes have been, and are, and may be again, I will state the most prominent points ; facts that have existed, and which have been repeated, even very recently. In our own country and our own fevers, the consequences under these errors are compara- tively trifling ; yet the inconveniences, and even the mortality, are far from being so inconsiderable as a superficial thinker, or a person ignorant of medicine, would imagine. And what I have to remark offers another interesting, if painful example, of that class of fallacy arising from the influence of a popular term. The yellow fever ; this term, like the word typhus, was sufl[icient : it was reasoning and observation united. '• Yellow'* fever had generally been a mar^h fever: it was sufficient, there- fore, that to a fever, to any fever with this symptom, the term yellow fever was applied, and the whole question became de- termined without examination. When will mankind be freed from the slavery to words ? — when mankind learns to think and to reason. When the " yellow" fever, being the typhus, or contagi- ous disease, has been supposed the marsh, or non-conta- gious fever, the consequence has been neglect in intercept- ing communication, and in all those precautions which stop the progress of contagion ; the consequence has been mor- tality, which might have been prevented by the simplest precautions, and that mortality diffusing itself from town to town, and from sea-port to sea-port, across half the globe. This was the lamentable case of Gibraltar, very particu- larly. When the " yellow" fever has been the marsh, or non-contagious fever, the consequences have been different : less mortal, it is true, but, perhaps, quite as vexatious, and, municipally as well as commercially, far more troublesome. Hence cordons drawn round towns, with other troublesome and expensive arrangements to check an imaginary con- tagion, destructive of personal liberty and commerce ; — hence quarantine laws made and enforced against that which was 44 Dr. Mac Culloch on Malaria on Ship-hoard, not communicable, with great consequent commercial injury, and with great expense and inconvenience ; — and hence, also, collaterally or incidentally, the excitement of a temper which, j)artly justified by the results as here stated, has generated a kind of party spirit against all quarantine regulations ; and has even gone so far, in recent times, and in the hands of a few of violent tempers, or misapplied political feelings, or anxious for notoriety, or else delighting in universal opposition, as to pro- pose, and persist in, the propriety of suppressing all quarantine or sanitary regulations, even in the case of the plague. Of the last case to which I have here alluded, Alicante offers an example : while, if I dare not quote further illustrations, so I cannot venture either to enter into more minute details of the several grievous consequences which have resulted from the errors which I have here pointed at. It woidd require long detail to render these fully sensible to popular readers, ignorant of the facts and ignorant of medicine ; and though such detail might be rendered very interesting, I dare not so far infringe on my allotted space. Such readers would also ill comprehend how the medical practice must be affected by correct or false views as to the true nature of such a fever ; and if the differences required in the treatment are not always very considerable, there are many cases where they really are most important; while I need not suggest to any philosophical mind, that no physician can act correctly under vague, hesi- tating, or false views of the nature of the disorder which he is treating. As far as our own country is concerned, the results of this error are evil in a less proportion, as the diseases, of whatever nature, are less numerous and less severe. I will pass over what relates to the practice or the medical treatment, though it is by no means unimportant. It ought to be obvious, also, that if a non-contagious disorder shall be judged a contagious one, the precautions which prudence would suggest on this view, and which a correct practitioner would follow, if too often omitted from ignorance or carelessness, are of a nature to be attended with great inconvenience, and often with consi- derable expense as well as alarm. Such is removal ; such, separation, nurses, and much more ; matters which, expressed in so many simple w^ords, carry no weight, but the vexa- .Dr. Mac Culloch on Malaria on Ship-board, 45 tions and expenses arising from which will not easily be for- gotten by those who have suffered from them. The reverse mistake, that of treating a contagious fever as if it was not contagious, has scarcely, perhaps, occurred much in our own country, because our errors are of the reverse nature : but while this would soon take place, should the sect, which admits of no contagious fever, make progress, it is apparent that the consequences would be most pernicious, since they would be the propagation of the disease : the same events, if on a smaller scale, which occurred to so terrific an extent at Gibraltar. How this affects the case of ships, I shall defer till I speak on this specific subject, that I may consolidate what appertains to that most important question, and the main object of this paper, into the most compact possible form. But there is one serious consequence of this pre- vailing error, viz., that of confounding marsh fever with typhus ; which^ if less obviously apparent, I should be unpar- donable in passing by, since it is, perhaps, equal in bad results to all else. If the vulgar, and, above all, the shallow and self- elected, critics, with which the popular literature of the hour abounds, suppose that fevers arise from no causes, or drop down from the clouds under magic or mysteries unappreciable by philosophy, it is not necessary to answer this class of modern philosophers. That effects arise from causes is no very pro- found discovery ; and that effects may be regulated by regu- lating their causes, is not much more difficult to comprehend. Fevers, it is to be presumed, have their causes, like all other efiects ; and to know these, is to have made the first step, at least, in the management of the diseases in question. To command them, is to command the effect ; to be able to modify them, is to modify it ; to destroy them, or to intercept their action, is prevention ; and prevention is health, as far as this disease, extensive in quantity and in evil, is concerned. Let, then, an exact, accurate, and invariable distinction be drawn between contagious and non-contagious fevers ; typhus and marsh fevers : and if there are but these two classes or species, as I hope to show still further than I have already done, we have acquired a command, to a certain extent, over the causes — while this command is prevention. How to prevent 46 Dr. Mac Culloch on Malaria on Ship-board. typhus, every one knows : to prevent marsh fever the rules are equally obvious ; since it is to avoid the lands or circum- stances which produce them. The object of the Essay on Malaria was to describe those, for the purpose of prevention ; but that knowledge will become effective only when the dis- tinctions between the two kinds shall be truly and invariably drawn, and when the people and their physicians shall have learned to admit, first, that fevers have a cause, and next, that the cause of those fevers, which are not typhus, is marsh miasma or malaria. How this question applies to ships, also, to the subject especially in hand, must be peculiarly apparent. But the basis of the whole inquiry, the nature and causes of fevers, is so much in want of elucidation, and that elucidation is so necessary to a right understanding of the main question, that I must yet offer some remarks on this subject : while I also conceive that it will, in itself, not prove an uninteresting one to popular readers, thus treated ; since, while they do interest themselves much about it, they are in a state of great confusion of mind relating to the whole subject. If people will think and act for themselves on the subject of medicine, and if they will control their physicians, it is, at least, of importance that they should think correctly. That, on this question of the distinctions and causes of fevers, even Physic itself is not very clear at present, I hope to show : while, whether I succeed in convincing my own profession or not, it is, at least, my duty to state my own opinions, and the reasons on which they are founded. I need not touch on the causes of contagious fever ; they are known, and not disputed. The question is, whether there is any other cause of fever besides those, except the application of marsh miasma, or malaria. It appears to me that no others have, at least, been proved ; and if this be so, then it also follows that there are but two species of fever, contagious and marsh fever. For the purpose of establishing this merely, an inquiry into the causes of fever will be valuable ; but it will be directly useful in another way. If, of any effect or effects, there are more causes than one, our power over these is checked or diminished : should we even suspect more causes than one, and without proving them, our confidence in our philosophical Dr. Mac CuUoch on Malaria on Ship-hoard. 47 principles is weakened, and the results that might have been derived from them become more doubtful. In the case before us, it is most essential to ascertain, if this can be done, that, next to contagion, there is no other cause of fever than mal- aria ; because we have then acquired a sure knowledge, at least, as to the mode of prevention, if not an absolute power in this matter. If, for example, in a ship we can control contagion, and if, in the same case, we can equally remove malaria, or its action, there can be no fevers in ships, because we have laid our hands on the only causes. Absolutely to prove what I myself believe on this subject, is not possible ; because it is an attempt to prove a negative in a science which is not an accurate one, and because it is an attempt to oppose established habits and prejudices^ in a branch of knowledge which is especially governed by them. All that I can do, is to approximate the facts in as simple and logical an order as I can, and trust the effect to those who are in the habit of weighing moral probabilities ; for of this nature is the present argument. The power and effect of malaria are admitted : of this one cause of fever there is no doubt; but it is the custom in physic to say, that they are produced also by heat, or by cold, or by either of these united to moisture ; or, further, by fatigue, errors or deficiency of food, the passions of the mind, and some few other causes, inducing what physicians call de- bility. If it is a maxim in philosophy that superfluous causes ought not to be assumed, it is here worthy of remark, that all these causes of fevers were proposed or invented in the ignorance and infancy of physic ; and when the very existence of such a subject, chemically, as malaria, was so little suspected, that the influence, even of marshes, was attributed to moisture, heat, putrefaction, animalculae in the air, defective elasticity in the atmosphere, and any thing else which admitted of some well-sounding term. It is also not an unimportant remark here, that to these very same causes, enumerated as the causes of fevers, were attri- buted inflammations, and, indeed, all other diseases. Mankind is naturally inclined to causation ; and in this case physic has 48 Dr. Mac Culloch on Malaria on Ship-board. mustered everything which could be supposed capable of affect- ing the human body, hoping, perhaps, that if one failed, it was sure of at least including the real cause in the crowd. And, in fact, these words have always been used as a mere string of terms ; not one definite idea having been attached to them, nor to their supposed powers of action : they are but a portion of that phraseology which has ever been the substitute for philosophy in physic ; and not a very uncommon substi- tute also for reasoning in moral science. It is of some value, in such a case as this, to trace the origin and character of opinions ; as we may thus often shake the structure which we cannot directly demolish. If a single cause were always the sole agent in producing disease, there would be no difficulty in proving that not one of these was the cause of marsh fever, or of fever that is not contagious. Unfortunately, the condition of the subject to be acted on must also be taken into the account ; as there are predisposing as well as exciting causes. And these last being sometimes obscure and unknown, while the former may be obvious, physic has not unnaturally committed the error of taking up with what was most obvious ; while, in this case, ignorant or neglectful of the presence and power of malaria in all those least obvious instances which I have pointed out in that Essay, it has attributed to heat, or cold, or fatigue, or what not, as prime causes, that power which they possess but as secondary and assisting ones. But as the very nature of this question does not allow me to prove the nature of the cause from any single fact, we must try to produce, from a wide mass of such, what could not be deduced from individual or separate ones ; and should this be practicable, the proof is legitimate, because it is only thus that philosophy, in almost any case, arrives at truth. If I can prove that the one cause which is here assumed as the true one, acts as often as it is called into action, and that the power of the others is irregular and uncertain, as also that, in very plain cases, they do not act at all when present ; and further, that when they do appear to be the agents, that other demonstrated cause is also present, or probably existent, it appears to me that the point in question is proved as perfectly as anything Dr. Mac CuUoch on Malaria on Ship'board. 49 ever is proved in those sciences which do not admit of mathe- matical demonstration. I may divide the imaginary causes which physic has assigned into two classes ; — those which depend on man himself, includ- ing injurious diet, fatigue, the passions,' and so forth, are equally distributed, on a broad average, throughout mankind, everywhere, and at all seasons of the year, or in all climates. As to injurious conditions of temperature and of moisture, they are not amenable to the same universal average ; but they occur also under certain distinct sets of averages, entirely different from those which attend the existence and action of malaria. Now, if what I have termed human causes were the causes of non-contagious fever, that should occur indiscriminately, and on some equable general average, all over the world. That, admittedly, is not the fact ; and I may surely, therefore, safely dismiss them from the list of causes which physic has registered. There is nothing wanting, even to demonstration, as to this branch of these supposed causes. The second division of causes, consisting in modes of tem- perature, cannot be dismissed so briefly ; because physic, with its usual laxity of language, has even enumerated all the cir- cumstances, without the requisite discrimination. If they were really causes of fever, it is difficult to see how any one should escape ; or, rather, there would be found a certain average, or certain averages, of fevers equably spread over certain average climates all over the world, which is not the fact. I must make the discrimination here, for physic, which it has not itself done. The operations of temperature must consist in certain states, or changes, which can be defined. It may be continuous cold, or a mean heat, which we may, perhaps, safely take about 40'' (I need not be accurate here) ; or it may be conti- nuous heat, which, in a similar loose way, may be taken at 65°; or it may consist in sudden transitions from cold to heat, or the reverse. It is generally esteemed that the effect of mois- ture is dependent on temperature, or is a mode of the action of that cause : should it be thought otherwise, it may be dis- tinguished into excess or defect. Such is a more accurate JULY — SEPT. 1828. E ^ Dr. Mac Culloch on Malaria on Ship-board, definition as to this set of causes. Let us examine their values. Fever cannot be the produce of cold, because it does not occur as a consequence of cold climates or cold seasons ; and, still more remarkably, when the causes of malaria are present, fevers which are non-contagious do not occur in winter. And, on the contrary side, they do not occur in those hot and sandy tropical regions, where there is no water, and little or no vege- tation ; and where the heat is generally far more extreme than in those of an opposite character. Again, with respect to transitions from cold to heat, this is a common occurrence in such countries as Canada and Siberia, in spring, and yet, if marshes are not present, no fever is the consequence. Of the reverse nature, or of sudden and frequent transitions from heat to cold, there can be no examples more complete than the burning deserts of Africa, where hot days are followed by ex- tremely cold nights, and where, yet, fevers are notoriously not produced. If physic was in the habit of examining its facts before it drew its conclusions, it might have escaped many more unfounded ones with which it is filled, than this. If the supposed effects of moisture in excess are dependent on its connexion with temperature, the same reasoning is ap- plicable. If, on the contrary, mere moisture can act in pro- ducing fevers, by its excess, a fog, from any quarter, should be equally productive of these diseases; whereas I have shown, in the Essay on Malaria, that this never happens from the fogs that arrive from the west to us, from the wide ocean anywhere, from even on land in winter, when vegetation and heat are dormant, nor from the moist or foggy atmosphere of a moun- tainous region, where the fog is the ordinary cloud. Where fever is the apparent produce of such a moist atmosphere, it is where there are sufficient reasons to believe that it is the vehicle of malaria, and that it acts only as it contains that ascertained source of fever. As to defect of moisture, it can only act as producing evaporation from the body in an unusual degree ; and it is thus a case to be argued on the general considerations already offered on this supposed cause. Thus have I gone through all the supposed causes of non- contagious fever, having also, as I trust, shown that no proof Dr. Mac CuUoch on Malaria on Ship-board. 51 whatever has been offered of their power in producing these diseases, and that there is not even a probability that they are the real causes which they have so long been supposed, though they may well be aiding ones, either as they render the body more susceptible of the action of these, or as they may be in some cases the very vehicle of the true cause, or the poison in question. And I cannot help thinking that, in any other science than physic, such reasoning would be satisfactory : unfortu- nately, this one has never yet guided itself by the ordinary rules of philosophy, nor been accustomed to the severity of logic ; so that against its modes of faith, philosophy and logic are arrayed in vain. But its errors are those of imperfect observation in this case, and are founded on a fallacy which it will not be very difficult to explain. Fevers, non-contagious ones, are proved to be produced where vegetable decomposition abounds most, or is most rapid ; or wherever that unknown substance called Malaria, as contained in the air which has obtained this term from its effects, is present. And such fevers are also proved to increase with the increase and activity of these causes, for- merly explained ; to diminish with their diminution, and to disappear with their disappearance. This in itself approaches to a demonstration that here Ues the real cause : in any other science, in any science which was not governed by phrase- ology and prejudices, it would be considered demonstration. But the fallacy becomes plain. All the imaginary causes which I have been discussing, exist everywhere, and they must needs exist, therefore, where malaria does. They can always be traced, while malaria has been neglected ; while, in our own country in particular, the medical world has remained ignorant of it, or has most unaccountably thought fit to forget what has been well known, if never so accurately known as it ought to have been. It is always easy to have recourse to an obvious cause: under the prejudices of physic, those which I have been arguing against have been selected, habitually and tra- ditionally ; and thus those which were but the accessory causes often not even that, have been invested with the title of ori- ginal or true causes. Here I think I may drop this subject, leaving these argu- E 2 52 Dr. Mac Cullocli on Malaria on Ship-hoard. ments to make such impression as may be their fortune. As I do not wish to enter here on the question of predisposing causes ; and as I have shown that malaria is really present in thou- sands of cases where it is not now suspected, there will scarcely be any difficulty, with due attention, of tracing the real cause of those fevers which are not contagious. In the case imme- diately before us, I have shown that it exists in ships, even at sea, the produce of the vessel itself, and on the general prin- ciple of vegetable decomposition. To conclude, if I do not, myself, perceive the defects in the logic of this argument, I can have no objection to see them pointed out, since my object is to discover Truth ; never yet having comprehended what else there was worthy of the pur- suit of a rational being. And on this ground I may venture, rather, however, for the sake of professional than strictly popu- lar readers, to offer a few remarks, somewhat more specific, on the fevers of nosological and systematic writers. I have stated two fevers, or two species (using that word in its widest sense) of fever, perfectly distinguished by their pro- perty of being communicated or not, and equally distinguished by their causes — exciting causes, in medical phraseology. The Plague is another fever of a distinct character : the eruptive fevers, smallpox, scarlatina, and so forth, form a different set of species ; and, besides all these, there is a fever attending on local disorders — on inflammation or disorganization. The question is, are there any other fevers ? any fevers besides these last, which are not modifications of the fever of conta- gion, or the fever of marshes ? If there are any still received, I may safely now, I believe, reduce them to the modern sim- plicity, by ranking them under the Synocha and the Synochus of Cullen. May these not be reduced still lower, or ranked under one or other of the Two Fevers ? I think that they probably can ; and if so, we have but two fevers, and two causes of fever. As to the disorder itself, as it exists, it will then con- sist in nothing but varieties; and if this can be established, it is equally important, both in the view of practice and pre- vention, — to say nothing of the satisfaction which arises from generalization and simplification, and of the facility which these add to all our reasonings, and to our practice also. Dr. Mac Culloch on Malaria on Ship-board, 53 The contagious fever, or typhus, varies exceedingly in the degree of severity ; and this is also true of marsh fever. And while the term putrid fever has been applied to extreme cases of the former, slighter fevers, supposed to belong to the same species, have been popularly called low fever, and nervous fever, and so forth ; while these terms have also been adopted by physicians. Referring to the above-mentioned remarks on the causes of fever, to what is here generally said on this subject, and to all that physic really knows about fevers, or de- termining not to follow the common lax language and reasoning of this branch of science, but to limit myself to that which is known and proved, such a low or nervous fever must belong to one or other of these species ; namely, the contagious, or the marsh fever, because physic cannot prove another species and a third cause. Now it is true that a fever of this mild description can be produced by contagion, and the proof is, that such instances will occur, in an epidemic period, among severe cases ; while also such a mild disease will propagate itself, and even produce a severe case ; and while, further, the very cause may some- times be traced, for such an individual instance, in the expo- sure to a contagion. But I am very certain that if the very great majority of such mild fevers were carefully examined, they would be found to appertain to the marsh fever ; while the error here is only a part of that general error of which I have been treating. And, but for this standing and almost universal error, physicians ought to have perceived this long ago, and might ascertain it every day. They should have believed it always, and ought to believe it now, because they can trace no contagion whence these fevers could have arisen, and because they are dispersed cases occurring everywhere, and without the existence of any epidemic to which they could belong. If it does happen that many occur in one neighbourhood, or even, perhaps, in one house, thus giving the false impression of an epidemic and a contagion, I have already shown how this is the consequence of exposure to a common cause. But there are other circumstances indicating the same thing. There can be no fever without a cause ; there are but two 54 Dr. Mac Culloch on Malaria on Ship-board, causes proved : if it is not contagion, it must be miasma, or malaria. And, as I have formerly shown, this cause is widely spread : while, very certainly, these low, nervous fevers will be found to occur or prevail chiefly or solely where that cause exists, and while also the ver)^ individual cause, the exposure, can itself be often traced with care. Further, this low fever will be found chiefly to prevail in the very period and season of malaria ; as its range is that of summer, and chiefly of autumn, extending as far with us, often, as Christmas. And, lastly, the disorder itself has a peculiarity of character which ought always to have explained its true nature and cause. It does not propagate itself, as I formerly remarked of these fevers generally ; while physicians, pursuing the same systematic error, have, not without plausibility, according to their own views, attributed this, in all such cases, to the mild^ ness or slight severity of the case or disease. Still more, the mild fevers arising from contagion, or the real typhus mitior of nosology, is commonly short in duration, while slender in point of severity. But the very reverse is the common character of the nervous fever which is most common ; or its duration is commonly very great, even when it is so slight as scarcely to disable the patient. And, on this, I may remark generally, that if three weeks is a very general average duration for true typhus, the very mild cases will not last so long ; while four, or five, or six being the much more common extent of remit- tent or marsh fever, so will that form the period of the very mildest nervous fever that exists, as arising from malaria. And whenever a very mild fever does last many weeks, there being no relapse, we may be quite sure that its cause is malaria ; that it is a marsh fever, not typhus mitior. Thus, also, a relapse is rare in the very mild contagious fever, while it is so common in the marsh fevers, of whatever degree of severity, that we almost pronounce with certainty on its character, if there is even one relapse ; most certainly and confidently, if there should be more than one, or if the symptoms should spin out to an interminable length. There is one other fact, very common in these mild fevers ; and it is, at the same time, both so remarkable, and so charac- teristic, that it is only wonderful how it should be so very gene- Dr. Mac CuUoch on Malaria on Ship-board, 55 rally, or rather universally, overlooked ; why it did not explain, at all times, to every physician, the real nature of these low or nervous fevers, explanatory, or rather demonstrative, as it is. And it is not less remarkable, that it is a very common event in those extremely short fevers which have been called inflammatory fever, as I shall presently notice. It did not require this, among other examples of neglect, to prove how very mechanically physic is generally practised ; what an utter routine it is in the hands of the great majority ; how the mass follows whatever schools have taught or fashion may dictate, without inquiry or reflection. If any physician will watch these fevers when they are diminishing or terminating, he will generally find that the disorder assumes a distinct intermittent character ; slight enough, it is true, as an intermittent fever, but still having a due proportion to the original continued one — exactly that proportion, in reality, which a regular and marked intermittent does to the remittent marsh fever, of which it is the representative, or the progress. This in itself is a proof of the nature of the first or original disorder ; for it is most cer- tain that the contagious fever, or typhus, is not convertible into intermittent, and does not terminate in this manner. That this has been supposed, I know ; but it is only a continuation of the same general error — the original error of mistaking marsh fever for typhus — of mistaking the cases in question. I do not say that this slender intermittent, as the termination or subsidence of a slender low fever, is not obscure ; but I do say that every physician ought to be able to perceive it, while I have little doubt that, having thus been pointed out, they will be able to do so hereafter. And it is somewhat remarkable, while not unamusing, to observe, that it is perpetually cured by a sort of fashion or routine practice, while the prac- titioner himself does not perceive what he is doing ; not very well knowing, indeed, what he intended to do by his prescrip- tions. I allude to the practice of administering bark, " bark draughts," after such fevers, and in what is deemed the con- valescent state, on the general and mechanical notion of remov- ing debility by tonics ; the word debility and the term tonic having pretty nearly the same meaning — namely, no meaning at all. The cure, in this case, is not that of either convales- 56 Dr. Mac Culloch on Malaria on Ship-board. cence or debility ; it is, very simply, the cure of an intermit- tent ; and thus also does change of air, as it is called, restore such patients, after long dragging on under what is called convalescence — on the same principle as it cures a marked intermittent fever, and, not seldom, by removing the patient from the original and perpetually-renewing cause of the dis- ease. Such protracted convalescence, extremely common, not only after these slight cases, but after all fevers, is always, in fact, an intermittent, though never observed, and, perhaps, overlooked, partly because the original disorder was mistaken ; and I need not say how valuable this view, and a greater cor- rectness in distinguishing contagious from marsh fever, will become in practice, particularly when it is recollected to what an indefinite time the debility, often of mind as well as body, is frequently protracted, and how often, I am sorry to say, very injurious positive practices, to say nothing of neglect, are resorted to under false views of the nature of the evil. And I have little doubt, that while the supposed utility of bark in contagious fevers has been grounded on the great and. common error which forms the fundamental object of these remarks, so have the interminable disputes on this subject proceeded from the fact, that some of the disputers have been treating the marsh fever, without being aware of it, while others have been, under equal confusion, referring to the true typhus, the conta- gious disease. In illustrating at some length, but not more than was neces- sary, the mild or nervous fever, and in explaining that the typhus mitior of nosology is generally, or commonly, the marsh fever, or a modification of remittent, I have left little to say as to the only other fevers which require some explanation on the same ground. The first of these is the synochus, of Cullen's nosology. I do not pretend to doubt that a contagious typhus fever may commence with one class of symptoms, and terminate with another. But for a marsh fever to commence with what are called inflammatory symptoms, and to proceed to, and termi- nate with the reverse, is so extremely common, that I must, at least, suspect that a very large proportion of the cases esteemed synochus have really been instances of this fever. And that, Dr. Mac CuUoch on Malaria on Ship-board. 57 in practice, now daily in England, this is the truth, is perfectly apparent; and will be so to every one, who, hereafter at least, shall take the trouble to study fevers with a somewhat differ- ent care than they have hitherto received. That CuUen's own notions of fever were not very clear or definite, may appear a very bold doubt, particularly to those whose physic has been derived from Edinburgh ; but it is not the only doubt, by very many, which arises on studying, after twenty or thirty years of far other studies, works which, in that boyhood of knowledge which continues to be perpetuated through successive genera- tions, it would have been almost a crime to have not wondered at — to be wondered at now, in a very different manner. It is, however, an excuse for him, and one which I am pleased that I can make, that the comparative rarity of marsh fever in Scotland had probably deprived him of the means of forming very clear ideas on that subject, though in his day they were far from uncommon in Edinburgh ; that he had formed his notions on systematic writings, of a very vague nature for the most part, and that seeing, habitually, contagious fever among the poor of his city, he had made this disease his leading base and ground of judgment. The last of these diseases, of simple fevers, requiring notice, is the synocha, or inflammatory fever, in popular language. Its general characters are known ; but what is the cause of a fever in which there is no topical affection, which is not symp- tomatic, and which does not arise from contagion? Cold, heat, any thing else which physicians please ; but if still with- out local affection, what is its character, and whence does it arise ? I do not pretend to say : but it is proper that they also who have defined and described such a fever, should refer it to some general principle ; that the science of physic may not for ever wander about among words. This much is believed by those foreign physicians who have paid the most attention to marsh fever ; namely, that an intermittent (if this term is here admissible), or a fever produced by a marsh, may be limited to a single fit. Of course, it may extend to two, or more ; and thus the continued remittent (if I may coin a convenient phrase) may occupy any period, from one, to two, three or more days, onwards. Such a fever, in all its appearances, is 58 Dr. Mac Culloch on Malaria on Ship-board. the inflammatory fever, or the synocha of nosology ; and its termination is very often that which I have already noticed as the nervous fever — or it ends in a slender intermittent : in this form, and this only, it has yet occurred to myself. If it had another character and another cause, I should be pleased to see that demonstrated, not asserted : though 1 must not terminate this slight remark on this surely obscure disease, without re^ minding my readers that I have never assumed malaria to be the sole and indispensable cause of even decided intermittent fever. It appears to be the far prevalent one, but it is not de^ monstrated to be absolutely exclusive. I do not think that I could have dispensed with these pre- liminary remarks on fevers in general, in examining the ques^ tion especially in hand, that most important and serious ques- tion, what are the prevailing, or ordinary fevers which occur in ships ? Without these, all that I might have said would still have left a ground of evasion and cavil, or at least a demand on the general principles of the decision. That the remarks have run into some detail will, I hope, be compensated by their utility ; and I trust, that even independently of their bearings on the main question, the mere excitement of such an inquiry, mere doubts as to what is received, will effect some good ; while if they should be true, they cannot fail to be widely be- neficial. I may therefore proceed to this question, as it relates to ships ; and in a political and commercial view, to the naval service, and that of our vast commerce, and to the important consequences which flow from the health or otherwise of their crews. It surely cannot be necessary to say much as to the particu- lar necessity of health in the crews of ships, in whatever ser- vice ; on the very peculiar and perilous consequences of bad health, or of sickness, disability, death, or prevailing mortality. On shore, a sick man finds his substitute in any service ; and a dead man is so soon replaced, that death never concerns any one but the immediate dependents and sufferers. It is far otherwise at sea. For the sick, as for the dead, there is no substitute ; and when a definite labour has been allotted to a definite number, every diminution of the number of labourers is loss or inconvenience — often, ruin. Merchants, owners, and Dr. Mac CuUoch on Malaria on Ship-board, 59 commanders, will easily answer this question as it regards their own profits and losses ; though the readers of" this paper would scarcely even conjecture the answer, or might pass the whole subject with little notice. The very insurers at Lloyds can often answer it; for they know well how often the disability of a crew through ill health, through fevers, in fact, has been the cause of averages or losses, which they would gladly have prevented had they known how, and which it is no small part of the object of this essay to diminish or control. And I cannot help thinking, that even that great and respectable body of merchants will, before long, see their own interests in this matter — while not less open, as their history has proved, to the claims of humanity ; and that whenever conviction shall reach them, ihey will, through the well-known means lodged in their hands, promulgate, or even compel a system of regulations for insured ships, analogous to those which I shall hereafter pro- pose as to the naval service. As to that service, in the case of the periods of war in par- ticular, the inconveniences of bad health amongst the crews are matters of history ; and no small volume, while a most ter- rific one, might be produced to show what have been the con* sequences of bad health in the navy. And this bad health, to use the popular term, is fever ; or it is, at least, that in general : a sickly ship, in sea phraseology, is a ship with fevers. Formerly, the scurvy was an additional evil, now happily quelled. The history of the Havannah expedition, as given by Smollett, is one of those fearful records, of which naval history could furnish many more, if none perhaps so striking ; and even the readers of Roderick Random may, from this tale, form a sufficient idea of what they have not consulted in the serious memoir of the same unhappy adventure. If the miseries of Anson's most romantic and almost incre- dible expedition were not the exact consequences of fever, they will, at least, serve to prove what sickness can effect as to the service of the navy ; and when the writer of this paper knew one instance of a merchant vessel, steered, heaven knows how, into the Havannah, by the captain, lashed to the helm by himself, in a fever, with part of his crew sick and dead below, and the remainder delirious and rioting on the deck ; when an 60 Dr. Mac Culloch on Malaria on Ship-board. English frigate picked up at sea a slave-vessel drifting under the guidance of a crew, of which every individual was blind, even to the slaves themselves ; these are extreme cases, per- haps, yet to which parallels of some sort could be found, and from fevers alone, throughout the whole history of our com- merce and of our naval service. It cannot, therefore, fail to be a most important object to check or destroy the production and propagation of fevers in ships : since, if these are excluded, the crew of a ship is, now that the scurvy has disappeared through proper regulations, scarcely subject to any serious ill-health, or causes of mortality, at least, except from accidents. A ship at sea, barring this disease, is a far more healthy position than the shore, almost anywhere ; and the events have proved it such in every case, as is apparent from the history of voyages of discovery beyond numbering. The reasons ought to be obvious : at any rate, I ought not to prolong this paper by pointing them out. Could that which I am desirous of enforcing be effected, as I think it can, the consequences even to commerce would be most bene- ficial ; in the naval service they would be even greater ; while a very little consideration ought to show to every one, what I should not here be justified in detaihng, at the hazard of occu- pying another page. And the mode of proceeding for this end must be to deter- mine, first, what is the exact nature of the fevers which occur on board of ships ; secondly, what are the causes of them ; and lastly, having ascertained these, how they are to be removed, or their consequences prevented. A portion of this task is nearly accomplished in the preceding remarks on fevers : the rest will not occupy much space ; and if what I have said, and shall add, should prove well founded, I cannot help thinking that a most important set of facts have been ascertained in medical and statistical science, and that the consequences will prove most widely beneficial. No one can doubt that contagious fever occurs on board of ships, while the causes through which it may be introduced, and those which would make it spread, are obvious. I should be among the last indeed to desire to subvert this opinion, highly dangerous as I view that modern and yet limited dogma Dr. Mac Culloch on Malaria on Ship-board, Gl which has undertaken to deny the existence of contagion, even in the plague. I should be among the last for another reason-— and that is, experience ; a wide experience in the ordnance transport service during the war, both of the fact itself, and of the value of fumigations in exterminating the contagion. Yet it will be found, on a most careful examination, that this disease, typhus, forms a very small portion of all the fevers occurring on ship-board, and particularly of late years, since the great improvements which have been made in the economy of ships, the improved education of our naval surgeons, and the better understanding on the subject of contagion and its management, which has taken place in modern times. ^^ Not to go over again all the reasons for this opinion, which can be extracted partly from this paper, and partly from the work on malaria, and that on marsh fever, it is almost a suffi- cient general proof of it, that the fever of ships occurs chiefly in warm climates, and in tropical regions of course most fre- quently ; or generally in the circumstances where malaria is existent. To a certain degree, this has been familiarly known to naval surgeons from all times, as could not fail, in the case of crews, whether in boats or otherwise, subjected to the action of a pestilent marsh, a river, or shore. And while it has long been understood that the common " yellow fever" of the West Indies is not a contagious disorder, there could not have been any difficulty in perceiving that seamen on board, exposed to the same causes, must have suffered from a similar disease. Yet, in other circumstances, and where the disease has been precisely the same in nature, if perhaps differing in some ap- pearances, it has been considered a typhus ; a mistake far too easy to make, when the manner in which such a fever appears to spread in a ship is considered, when the characteristics of the two kinds of fever are often not to be distinguished, and when also, if Pringle is right, the marsh fever can, under con- finement, even produce the contagious one, or is actually con- verted into it. The particularly evil consequences of this mistake, in such a case, are apparent ; though, perhaps, the actual treatment of the patient will not be much affected by the error. The cause remaining unknown, there can be no fit method of prevention 62 Dr. Mac CuUoch on Malaria on Ship-hoard, adopted ; and there is none : while much toil and inconveni- ence also are often incurred in attempting to control an ima- nary contagion. The great object of this paper therefore is to point out those causes, that they may be removed, and with that, such diseases prevented ; and if it was first necessary to explain the differences in fevers, and to show how easily mis- takes must arise, that object is now sufficiently accomplished. There are two great and distinct causes whence ships are exposed to malaria ; while if the one has been long familiar, serious errora have nevertheless taken place as to the power of this, and as to the modes in which the danger was incurred. The other has never, as far as I can discover, been pointed out in any medical or other writings, till it was indicated in the Essay on Malaria ; while, from being the least suspected, and from its power of occurring in any ship, in any climate and season, and even at sea, it is the most important one. Against both, precautions are necessary ; and against both, they are available; while, for both cases, they are different. I must explain both here in somewhat greater detail than I did in the Essay on Malaria, for the purpose of the two distinct sets of regulations which ought to be founded on them for the objects of prevention. Communication with the shore, in a climate or country pro- ductive of malaria, is the cause generally known to medical men as generating fevers in ships. But the error here has chiefly been that of not attending to the distance to which this influence extended; practically also, that of neglecting such precautions in ordinary cases, as ought to be well known : which, in fact, are known, but are passed over from thoughtless- ness, or from want of recent writings urging, or repeating that which many have forgotten, and others have not acquired. I have shown distinctly, that malaria is currently propagated to distances of at least three miles ; and I have given ample reason to believe, in the Essay on Malaria, (I mean in the book itself,) that this influence is very far more widely effective. I have indeed decidedly ascertained since, the instantaneous production of fever through a land breeze, at five miles, to a ship at anchor. Thus it is, apparently, that fevers occur so commonly in ships on nearing the tropical lands ; and hence Dr. Mac Culloch on Malaria on Ship-board, 63 the calentures, (calentura) as they were formerly termed, of which we read in our old voyages under these circumstances. Such an event will happen chiefly under leeward positions as to the vessel, and of course will occur with land winds, where there are winds of this nature on any shore. And it is also evident how this will occur chiefly at night ; because this is not only the period of the land wind, but because the mere in- fluence of evening and morning, or of night altogether, in the production or propagation of malaria is very considerable, as I have elsewhere shown. Thus chiefly we explain the effects of dews in these climates, as the vehicle of the poison. And if a ship is ever so situated as to the land, as to have her decks covered with dew in the morning, that is in itself a proof that she is within the reach of danger, and ought to be moved ; while I need not say that such dews are actually the perpetual causes of fever to the men of the night watches. And here also we may see the necessity of reducing those watches to the least possible number of men, if the circumstances of the ship do not allow her to leave her position, or weigh and stand out to sea at night. ^ And as to the land wind, I may give one general rule appli- cable to all circumstances of ships engaged in tropical climates, or in warm ones generally. It is always attended by that smell of land which is better known than it is easy to describe, and which many delicate or experienced individuals can perceive at great distances. And while I have no doubt, from the facts and reasonings given in the Essay on Malaria, that this sub- stance can be conveyed as far as the smell of land is percep- tible, it would be prudent, whenever that can be done, in such a climate, to weigh and run to sea, and particularly, of course, during the night, when the danger is augmented. And there are circumstances in which a vessel should not even wait for the breeze, but be at least a-trip and ready to get under weigh at the instant it comes to blow ; since in one instance which I have noticed in that essay, in these very circumstances, and even where the captain of a frigate was habitually attentive to this precaution, to such a degree indeed as to order all the su- perfluous men below on this shift of wind, the armourer was seized with the fatal cholera, in the very act of clearing an 64 Dr. Mac CuUoch on Malaria on Ship-hoard, obstruction in the chain cable, while others of the crew, un- avoidably employed on deck, also died in a few hours of the same disease ; the attack having attended, in an instant, the first perception of the land smell. And if this is an ex- treme case, it is precisely the one required as a proof of the truth and value of these remarks. In ordinary circumstances, the disease would have been a fever; but coming on less de- cidedly, and easily attributed to other causes, the same reason- ing would not have been deduced from it. And if the mere delay of a few minutes in this case, arising from the accident to the cable, was, in the captain's own estimation, the cause of this loss, I must also remark, that the vessel was then about five miles from the shore. How much Blane and others have erred, and how dangerously, in fixing on one thousand, and on three thousand yards, as the utmost limit of the range of malaria in these cases, I need not say. The other circumstances in which ships and their crews are exposed to the malaria of the shore, are more familiar and admitted; however much the necessary precautions are for ever neglected. I can afford to be comparatively brief, there- fore, on these ; and their enumeration will complete all that is necessary as to the first leading cause of fevers, or of marsh fevers, in ships. The general cause of evil in this case, is familiarity with the shore ; the landing of men, mider whatever circumstances, in situations where malaria exists. The danger is evidently greater as the harbour or anchorage is most exposed to the effluvia of marshes or jungles ; but I need not here repeat circumstances which were pointed out in the former essay. That it is also greatest at night, or between sunset and sunrise, has been further shown ; so that, on both these considerations, addi- tional precautions ought to be founded. And it has so hap- pened, in general, from obvious enough causes, that most of the tropical towns and harbours are situated in the most unhealthy spots : while, not seldom, a bad one has been chosen where a salubrious one was equally convenient, or, as in the case of Batavia, artificial means have, by their adoption, rendered that which was naturally bad still worse. And the same indeed is too often true, even in Europe, as in the Mediterranean : the Dr. Mac Culloch on Malaria on Ship-board. 65 ignorance of the days in which these places were chosen, hav- ing combined with their convenience, while, in too many of them, modern nations have neglected those remedies or means of improvement respecting which the ancients showed so much anxiety. In practice, it is the duty of the commanders of ships to avoid all that can be avoided respecting communication with the shore, through the landing of men, and particularly in per- nicious spots, or at dangerous hours ; while an enumeration of the former would comprise the geography of half the sea-ports of the globe. In ships of war particularly, where this really can be effected, men ought never to be permitted on shore upon leave at night, nor even officers, though the hazard to them is less; and when it is supposed, as is not uncommon, that the men affected with fever, have caught a contagious fever from improper communication, it will be found that the disease is simply the marsh fever thus induced. Thus, also, ships of war can procure their stores from the depots and dock-yards, as for example, at Port Royal, Jamaica, and at St. Lucia, through launches or shore boats, by means of natives or negroes im- passive to the effects of malaria ; and in this way can such vessels often avoid anchoring, at least near to the shore, or even contrive to run out to sea every night. How far merchant vessels can attend to these precautions must depend on the nature of their particular affairs with the shore and on the strength of their crews ; very materially also it will depend on the character of the captain — on his discernment, docility, humanity, and the interest he may feel for his owners. But I need not pursue what I have here said through details more minute, as the ramifications ought not to be difficult to conceive. And this is not speculative matter : the practice in question has been tried by many enlightened and active officers, when their own discernment had taught where the danger lay, and with the most marked success. I need not quote more than two instances, though I could easily accumulate many more. The first is the case of Captain Smyth, well known through his account of Sicily, and his long and laborious surveys in the Mediterranean ; and so successful did these several attentions prove, that he did not lose a man, or suffer from a fever during JULY— SEPT. 1828. F 66 Dr. Mac Culloch on Malaria on Ship-hoard. the many years he was employed there, in every harbour and on every coast of Spain, Italy, Greece, and Africa, and ne- cessarily under the most intimate communication with places as pestiferous as any in the world. This is a case comprising a long-continued train of the ex- periments and precautions in question, and nothing cati be conceived more satisfactory. The only other instance which 1 shall quote, is, as a solitary case, not less remarkable. It is from Admiral Sir Henry Baynton, who informs me, that when in the command of the Quebec and Nereide frigates at Jamaica, he was in the habit, like others, of anchoring near the dock- yard at Port Royal, the pestilent marsh near which is well known, and that he invariably carried to sea a fever by which he lost many men. Perceiving the cause, and that cause the one which I have here stated ; he determined to change his plan, when afterwards in the command of the Cumberland, 74, by anchoring at a greater distance ; and though he was de- tained in port during most of the hurricane months, or the most sickly season, he, to his own great surprise, as he states it, but by using the several precautions which it is the object of this paper to point out, retained his whole crew in as good health " as if they had been in the British Channel," there not being one man on the sick list in a crew of 590 men : an in- stance, probably, scarcely known in naval records. Here there is an example of what may be done by the com- bination of knowledge and attention on the part of a comman- der, even in the most unhealthy climates and situations ; while the contrasts which I might easily draw between this and the histories of other ships in similar circumstances, would present a most extraordinary, and a not less fearful picture ; though I must avoid what would give pain to many individuals still living, and even through those that are dead, to many more. Let those, however, who wish to see what such a contrast can be, read Smollett's account to which I formerly referred ; and then ask themselves whether these speculations are visionary, or whether, on the contrary, the deepest blame does not attach to all those who have suffered such atrocities, as it will continue to do to all those who shall suffer them hereafter, ■where all possess the same power as the excellent officer whom Dr. Mac Culloch on Malaria on Ship-hoard, 67 1 have here brought forward as authority. And though I might refer to the journals of the several ships under his command, contrasting them with those of the same ships under other com- manders, I wish to avoid doing this, from feeling that I cannot allot him the praise which he so highly deserves, without an implication of blame on his predecessors and followers in the same vessels. And the same reason induces me to suppress even some other names where I might equally have allotted praise ; as, though the readers of this journal may not be aware of it, the records of the Admiralty, and the personal knowledge of individuals in the navy, would easily point out those officers to whose neglect there has been owing a loss of life, with in- convenience to the service, and an expenditure of the public money, implied in the loss of those lives, which it is most pain- ful to think of, especially when we know how easily all this might have been avoided. There is but one other modification of the connexion of ships with the shore in tropical and insalubrious climates, which seems to demand a specific notice, and for the sake of the precau- tions applicable to it, under this division of the general subject of the influence of malaria on the healths and lives of seamen. I allude to a particular class of service which, as perhaps most common on the coast of Africa, is best understood by this allusion. It is the sending boats on shore, for the purposes, among others, of wooding and watering. The consequences are but too well known : fevers of the worst class, and a very general or common mortality, often highly inconvenient, put- ting out of question all views of mere humanity. I have said, in the general Essay on Malaria, that much of this service ought not to be performed by good seamen, and would be a fitting labour for convicts ; and that it is difficult to compre- hend the policy which allots, as punishment to those who have forfeited their lives to the state, the best of climates and the most salubrious of occupations, while what almost amounts to a condemnation to death, is the lot of innocent and of valuable men. And on this subject, as at least an easy and specific remedy, 1 have the experience of Captain Coffin to state ; who, in these circumstances, applied for a party of negroes from the shore, F2 68 Dr. Mac Culloch on Malaria on Ship-board. and who, in consequence, preserved the lives of his crew, which he must otherwise have lost in the usual proportion. And his recommendation is, that a ship, or more, of no value, should be kept on the African coast, to be the receptacle of volunteer negroes for this particular service ; a matter easily accom- plished, and of which the consequences could not fail to be most beneficial. As to ordinary precautions, in the case of seamen, it should be an invariable rule to suffer no boat to enter a river, or to be on shore at all, between sunset and sun- rise ; and further, to prevent, as far as possible, any such boat from being on the shore, or in a river at low water, — as that is the period when, from the exposure of the mud, the malaria is active, while its presence is betrayed by the very smell. Among other precautions, applicable to particular cases, I stated in the Essay on Malaria, and from African authority, that the lighting of fires in the service of cutting wood was found to be an effectual preventive; and it will be easy for any ofHcer to see in what exact cases it may be applied. It is another general precaution, applicable to every case of this nature, every service of seamen on shore in a hot climate, never to suffer men to go on shore, nor even to be on the deck in harbour, further than as the watches are concerned, before breakfast, or without at least some allowance of spirits; since, in every case, this precaution has been found of great use, as the standing practice of Holland fully tes- tifies. And, for the same reason, the smoking of to- bacco, which, from obvious motives, is discouraged in ships, ought not only to be permitted, but commanded ; since ample experience has also shown its great utility. To suffer no men to be unnecessarily on deck when near the shore, is a pre- caution to be deduced from what has already been said ; and this rule offers a particularly obvious reason for reducing the night-watches, in particular, to the lowest admissible number. With respect to some of these circumstances, and very remark- ably as to the dangerous influence of the morning, as well as the evening, the experience of India offers some very remark- able illustrations ; as the great losses of men have always occurred in those regiments where a martinet feeling in the commanding officer (as the phrase is) has led to the regulair I)r. Mac Culloch on Malaria on Ship-board, 69 drilling of the men before sunrise, that they might avoid the imaginary evil effects of the heat of the day. I use the term imaginary with little scruple, convinced that there is incom- parably less danger at this period than at any other. There is always much alarm, it is true, at what is called a coup de soleil ; an unlucky term, producing the same consequences on the mind as other terms do. I do not say that phrenitis, or, perhaps, common fever may not arise from this cause ; but it is abundantly plain, from every case of this nature which I have found accurately described, that such an imaginary coup de soleil, or effect of a hot sun, is, in reality, most generally the fever in question, produced at a very different time of the day generally, and from a very different cause ; though, from the natural effects of this prejudice and this term, easily attri- buted to the action of the sun. I have but one suggestion more to offer in the way of pre- vention, as to this usual source of the action of malaria on the crews of ships. All the people of Southern Europe think that it enters by the lungs ; and, in Malta, in Spain, in Italy, in Sardinia, perhaps, more widely, it is thought that the fever may be warded off in perilous situations, by stopping the mouth and nose : in Italy it is commonly held that a gauze veil is effectual. If this be fact, it is an easy remedy ; if it is still to be proved, there can be no better opportunity of proving its truth or otherwise, than on the African coast, by obliging any one boat's crew to use this expedient, and by trying what the results would be as compared to those with another boat, without this precaution. I have thus gone through, in as much detail as my space would afford, and in as much, I hope, as is really necessary for those who choose to reflect on this subject, the first great cause of the production of fevers in ships, from malaria ; and the modes of regulation and prevention which are applicable to that cause : it remains to examine the other. In the Essay on Malaria, I attempted to show that this poi- son was the produce of ships themselves, in circumstances independent of the land ; the principle being the same, and the poison generated by the action of water on the wood of the ship, — an ordinary instance, in reality, of vegetable de- Tfilf Dr. Mac CuUoch on Malaria on Ship-board, composition. I then quoted the case ofsugar-ships as especially in point ; and a further examination of facts has confirmed me in the belief, that the general fact is not to be questioned, and that this is the real cause of those fevers in ships, which are so commonly attributed to contagion deemed typhus ; never suspected to arise from malaria, and consequently not supposed to be, by any possibility, remittent or marsh fevers, because occurring at sea, or in circumstances where no exposure to an unhealthy coast has taken place. Not to accumulate specific cases, which ought really to be unnecessary, I will here note but one remarkable fact bearing on this point, where an officer was suddenly struck with what is called apoplexy on the open- ing of a water-cask, and has remained partially paralytic for life : the first effect, and the whole subsequent disease, being precisely what occurs in France and Italy so frequently, from a sudden and transient exposure to a peculiarly virulent or condensed malaria. This cause then, or bilge-water, is that source of malaria and fever in ships which may be deemed universal, because it can occur in almost any climate, and, under neglect, in any ship, even at sea, and without the least communication with the land. And if it should thus be produced, it can scarcely be guarded against, from the very circumstances of a ship ; so that it is peculiarly necessary that the cause itself should be remedied in limine. And it is least of all surprising that the fevers occurring from this cause, this mode of the presence of malaria, should have been considered as typhus, and as the produce of a contagion, casually received into the ship, and con- tinuing to act from adhering to the vessel itself or its furniture. It must always have appeared as the produce of the vessel itself, which it in fact was 5 while the unsuspected cause has led, in anxious hands, to fumigations, whitewashing, scower- ing, and all those other obvious remedies against contagion, which must ever have been inefficacious, as they, in fact, have proved ; because no precautions of this nature could have checked the action of a poison generated every hour, and sup- plied as fast as even ventilation could dissipate it. And if this very circumstance made it appear that the cause was contagion, so that has often appeared to be confirmed by Dr. Mac CuUoch on Malaria on Ship-beard. 71 the fever in question always appearing to commence in some particular part of the vessel, and to spread from that point. And while the fact was and is so, it is one that aids in confirm- ing the very cause here assigned. It will depend on the. quality and construction of the particular vessel where, ex- actly, it is to appear ; but it will be found that such a fever commences about the cable-tier, or in some other place through which the air from the hold ascends, and that the men, most exposed to the bilge-water are exactly those who suffer most from it. I hope that I need not enter into much more detail as to this cause. It will naturally be a more active one in a hot climate than a cold, and with a crowded crew than a thin one : it will depend much on the cargo; and thus, as it is pecuharly notorious with sugar cargoes, has it also occurred very remark- ably with coffee and with corn ; some very remarkable instances of most destructive fevers from leakage with a corn cargo, being even familiar to those in any way acquainted with the ordinary commercial history of shipping. I have also reason to believe that a new ship is more subject to it than an old one, that is, if she should be leaky, or the pumps neglected ; just as a new cask is decomposed by water, and spoils that more readily than an old one. Thus also, which is useful know- ledge as matter of precaution, it occurs more readily with gravel or mud ballast, and less easily with iron ; while it ap- pears, also, that the malaria is most virulent in a ship which, from the abundance of vermin, of rats and cockroaches, for example, contains putrifying animal as well as vegetable mat- ter. It has been suspected, but not proved, that on shore, ii^ marshes and sewers, for instance, the addition of animal matter increased the production or virulence of malaria ; but if that has not been proved, the facts in question may, at least, give some colour to the suspicion. I have but one other remark to make on this cause, and it is one that, like all else, refers to matters of prevention. This is, that the closing or separation of a vessel by means of bulk- heads, adds very much to the evil, and very obviously, by impeding ventilation and the dissipation of the poison. And this is so far from speculative matter, that were it not for the 72 Dr. Mac CuUoch on Malaria on Ship-hoards impropriety of mentioning names, now high in office as in rank, I could quote two pointed cases of ships of the hne, with equal crews, and on the same services, on the coast of Brazil, where, while the one lost a large number of men by the remittent fever, obviously generated in the vessel, the other preserved her health ; the difference of the two being, that the one was closed up by bulk-heads, and that the commander of the other, aware of their evil effects, had caused the whole to be cleared away. I hope that I need not dwell longer on this particular source of the fevers of ships : the precautions and modes of prevention to which these statements lead will occupy but little space. Cleanliness and ventilation are the leading points ; but to be conducted in a far other manner and on very differ- ent views from those in which they have usually been done, because directed to very different purposes. It must be evident, in the first place, that the laborious system of scouring and whitewashing is useless, otherwise than it is advantageous for the sake of general cleanliness. It is equally plain, that fumigations, though with the mineral acids, must be without effect against a poison which is in a state of hourly production and renewal. Nor can fires have more than a temporary effect, since that must cease with the period of their action. The radical cure consists in cleanliness as to the hold of the vessel, for there the evil lies. This is the marsh, if I may apply such a term ; the steady source of the malaria : and the remedy is as simple as it is easy ; since it consists in nothing more than washing the ship by means of the plug, daily, or as often as that is necessary. And experience has amply proved the value of this practice. It was the rule of Admiral Baynton and of Captain Smyth, to continue this operation till the pump brought up water as clear as that of the sea outside, daily ; and the success of these commanders, under this and the other precautions, I have already stated. In the reverse way, experience has proved the same thing ; since, in some of the most notorious and destructive instances of fevers in ships of war, many of which I could name but must not, it was found that from neglect of this process, the hold and ballast were a mass of mud ; and, what is more remark* Dr. Mac Culloch on Malaria on Ship-hoard. 73 able, that the character of the very same ship, as to sickness or health, had always changed with the change of commanders, just as the sailing qualities of a vessel has been known to do under similar changes.. What else may be said as to prevention in this case, relates to ventilation. Separations in a ship are often unavoidable ; to a certain extent, always indispensible. But ventilation can still be effected through wind-sails, or other well-known means ; and if the general principles here laid down should ever be admitted and understood in the Navy, or in ships generally, an attentive and able officer will find no difficulty, under any possible circumstance, whether as it relates to this cause or the former, in adopting such regulations of detail as the general principles indicate ; and such as will doubtless prove efficacious in diminishing or preventing this long-standing and most active cause of mortality in the Navy, or in ships of whatever nature. Admiral Baynton well remarks, that his own crews were always far healthier than an equal number of people in any country town in England ; and, in truth, it ought to be so ; since, Avith the exception of these fevers, for ever incurred through the grossest neglect, it is not easy to conceive a situation more salubrious than that of a ship at sea, more free, at least, when we consider the usages and conditions of the inhabitants, and their modes of life, from mortal diseases. I think that I need not proceed ; because, if what I have said is not capable of producing conviction, I cannot conceive that anything will. In this case, I must trust to Time, the great friend to all improvement, who for ever effects what evidence and reason cannot. But it will be convenient to place, in a brief and simple summary, the chief regulations which have been here proposed, that they may be more conveniently com- mitted to memory, should any one think that the entire re- commendation deserves attention. With respect to the possible effects of land or its malaria on ships, it would be prudent to avoid approaching this within a a certain distance, in tropical climates, and on low shores espe- cially, unless in cases of necessity 5 and this distance to be limited to not less than three or four miles. Whenever anchoring can be dispensed with in such cases, it 74 pi"' Mac Culloch on Malaria on Ship-board, ought to be avoided ; and ships should be directed to be off and on, particularly at night, whenever the service admits of this, as the chief danger is between sunset and sunrise. If, in certain harbours and ports, such as St. Lucia, for example, or Port Royal, stores can be sent on board by launches or otherwise, this should be done, to prevent the hazard from anchoring in a port. Boats should never be sent ashore from sunset till after sun- rise, and men should never have leave at night. No man should leave the ship in the morning till after breakfast, or after a dram ; and smoking, or tobacco in any shape, according to the practice of Holland, should be made the universal practice. In any case of a vessel hovering or anchored on a tropical or other suspected coast within four or five miles, should the sea breeze, or any wind, change, or come to blow off shore, they ought to stand off or weigh immediately ; and in these cases, also, all hands unnecessary on deck should be ordered below. The night-watches, in all these cases, ought to bo reduced to the least possible number of men ; and the men of these watches ought not merely to be permitted, but ordered, to smoke while on deck. Boats employed in cutting wood in tropical rivers, should always arrive, if possible, and quit, during full water, as the fevers are produced during the exposure of the mud. If fires can be lighted during this service, that ought to be a standing order. No boat to be in such a place at night. It is believed that gauze veils prevent the malaria from attacking those exposed to it ; — the least that can be said is, that it deserves a trial. These are the general precautions ; and it is believed that if adhered to, with such others as may be derived from the same general principles, a great portion of the mortality in ships in hot climates would be avoided. I will only add, that for African service it is recommended that negroes or natives should be adopted to perform those duties, in wooding and watering, that have proved so destructive to British seamen. The other set of precautions relate to the production of malaria from bilge-water, or a foul ship, and they are, per- Dr. Mac Culloch on Malaria on Ship'board^ 75 haps, more within the reach of positive regulations than the former. The first general rule is this; that the ship should be washed every day, or as often as is practicable, by means of the plug, nor is the washing to be deemed effectual, till the water from the pump is as clear as that outside. As, in any case of the production of malaria from the ship itself, its very construction renders it peculiarly effective, through confinement, every practicable mode of ventilation should be resorted to ; while, as contagion is not the cause of these fevers, all the common plans of whitewashing, and so forth, usually adopted, may be dispensed with, as producing trouble and doing no good : and, in this view, all fumigations, from whatever materials, are useless ; because the effect of them is temporary, and necessarily nothing, when the poison- ous cause is in a state of perpetual production. This has been a leading source of deception and evil, and particularly so, as appearing to be founded on solid principles, while these were, in reality, false ones. On the view of confinement, it is also proper that no divi- sions or bulk-heads should be suffered in a ship, if they can be dispensed with, as they concentrate and render the poison more active. To conclude, if these regulations could be rendered effec- tual, it is believed that the greatest cause of mortality in ships would be removed ; and if, in addition to this, every ship, leav- ing any port, were adequately fumigated by sulphurous acid, and the persons and clothes of newly-entered men, or men on shore on leave, were attended to, by the well-known means, together with such other equally familiar precautions as are re-s commended against contagion, it is believed that fever would shortly become unknown in the British Navy ; and further j that as this is the only real cause of mortality, remembering always that dysentery and cholera also arise from malaria, and from the same causes, a ship would, in any case, be the healthiest of residences, and thus the mortality of the sea would become an absolute trifle to what it has hitherto been. I may now conclude. — ^The past history of the Navy is a history of fearful or most injurious mortalities from fevers. The inconveniences to the Service, ill appreciated by landa* 76 Dr. Mac Culloch on Malaria on Ship-board. men, are but too well known to the Navy, and to the State also. The expenditure of life, and therefore of money, is not less known, at least, in the accounts, if placed, as usual, to the general average of unavoidable casualties. What regards humanity is not worth reckoning, it is to be presumed. If all this can be prevented, he who shall prevent it will have effected no small good, in many ways. The detail of past evils and future possible benefits would form a very curious and instruc- tive picture ; it would carry even an air of romance. In the merchant service, the evils are radically the same, but the effects are in some respects different. Humanity here, also, reckons for nothing, as long as the dead man can be replaced by a living one. Yet there is loss : wages are paid for services not performed; vessels are disabled from inefficiency of hands ; and vessels are lost. The owners escape, it is true, for they are insured. Who is there to care ? — the insurers. The in- surers are so divided and diluted, that there is no one to care. The merchant service is little likely to do anything towards improving the health of ships. It must finally rest with the Admiralty, with the State. That when the State believes what is here detailed to be true, it will regulate accordingly, we cannot doubt ; but we may safely doubt if this reasoning is adequate to command their belief. * Lineaments of Leanness. By William Wadd, Esq., F.L.S. It may naturally be supposed, from the cases and comments on corpulence, that the ^^ fat and /azr" have not been the only persons who have consulted me ; the man who knows how to reduce " the fat'' ought to know how to " fatten the lean ;" and, accordingly, I have occasionally been visited by ** quelques Anatomies Vivantes,^^ and although Mons. ^, * This extraordinary production of nature, pronounced by the most eminent of the faculty in France and England, to be a " great phenome- non,'" was brought, as we are told, to this country, at a considerable expense, to contribute to the advancement of science ! The expense of keeping a skeleton we cannot calculate from any practical experience in this country ; but we may presume it was not much ; *' a recreative excur- sion,'" for a party of such persons, would, it may be presumed, not cost so large a sum as the convivial committee of City lands. Quere ? which Was advanced most by the skeleton's visit, the Englishman's philosophy, or the Frenchman's fortune ? Lineaments of Leanness. 77 the real living skeleton, never did me the honour of a visit, I have seen full as great curiosities as the said Monsieur, within the circle of my own acquaintance ; and, in the persons of two of my most intimate friends, witnessed the most extraordinary instances of emaciation that the human frame could possibly exhibit. One of these was a gentleman about forty years of age ; the other was one of the most lovely and beautiful of her sex, who, when she died, at the early age of thirty, presented the resemblance of an ivory skeleton, covered with thin parch- ment. These cases were similar in appearance and progress ; and each of them the effect of great organic disease, in the mesen- teric glands and abdominal viscera. The first of these cases, was Major P , who, after much military service, and much harder duty as regarded his health, in the service of convi- viality and good living, became a barrack-master in Sussex. I had not seen him for a year or two, when one morning, he called me up, having suddenly left his quarters, " to seek my friendly advice, on matters of the utmost importance !" For some moments I could not recognize my friend, — I knew him not ; how should I ? an insane skeleton addressed me ! It spoke of circumstances I knew, but in a voice I did not know. Never, in my professional hfe, was I more distressingly affected, I met the momentary difficulty of contending feelings as well as I could, and, as soon as circumstances permitted, deposited a living skeleton in the charge of his family. He lived a few weeks after, eating voraciously ; and swallowed, or rather bolted, some large lumps of meat within a few hours of his death. There are, however, cases of the absorption of fat, the causes of which it is impossible to ascertain. A curious case is related by Halle in the ' Memoires de I'ln- stitut National,' of a young woman who gradually became emaciated, without any diminution of appetite, and without any specific complaint. At the age of twenty-one, the emaciation commenced ; and from that time went on progressively : she had no fever, no cough, no sweatings, no oedematous swellings whatever ; and the excretions were quite natural. She died at the age of twenty-five, having been confined to her bed only fifteen hours, and in these were included the usual hours of 78 Lineaments of Leanness. rest. The only peculiarities discovered, on dissection, were the almost total want of fat, and the obliteration, in a great mea- sure, of the lymphatic system. The lactealswere invisible ; all the glands were remarkably small ; the inguinal glands, in par* ticular, were quite shrunk, and the vessels leading to them were almost impervious. Halle therefore concludes, that this case affords an example of atrophy, independent of any organic affection, except what resulted from the successive obliteration of the lymphatic system. Two remarkable instances are mentioned by Lorry — one of which will sufficiently illustrate this remark. A person advanced in years, and aflPected with melancholy, became, without any evident cause, in such a dry state, as to be unable to move without producing a horrid crackling noise in all his bones, even the spine, to such a degree, that (being a priest) he was obliged to give up saying mass, as the noise was so great as to astonish the vulgar, and make children laugh. Sudden emaciation and absorption of fat, however the effect of diseased organic structure, or acute disease, does not pro- perly belong to, or characterise that opposite state, or anti-^ thesis to corpulence, known by the term leanness, which is always attended by extreme tension and dryness of the cellular membrane, very frequently by weakness in the digestive powers, but not constantly, as we sometimes find thin and lean persons, eat more in quantity than others. It is not eating alone, however, but digestion that gives strength and nourishment : yet digestion may be perfect, and assimilation of chyle into blood imperfect ; for, that the quan- tity of nourishment does not depend on the quantity of food, is evinced, by the most voracious eaters being found among the leanest of their kind. The act of eating gives rise to three subsequent processes, — * digestion — chymefaction — and chylefaction. The production of fat seems to depend most on this latter process, and whether as Father Paul says, ** the little we take prospers with us," or whether we fall off though fed on turtle, seems to depend on the facility of chylefaction ; a process carried on out of the Stomach, in the small intestines, a lower portion of the aliraen* Lineamenis of Leanness, 79 tary canal, to which the attention of modern physicians and physiologists has been particularly directed ; and to which we may attribute the duodenal diseases, and discrepancies, now so fashionable. There are many of the phenomena of digestion perfectly in- telligible ; there are others that are not sO ; and from the pecu- liar effects of certain alimentary substances, we are led to con* elude, that there is a shorter road for some of the excretions, than by the lacteals and general circulation. And although we can very readily explain and account for various circum- stances connected with digestion and chylefaction, there are many questions arising out of them, that an ingenious casuist may suggest, to which we can give no other answer than the doctors did to Voltaire, when he proposed on this subject the following question : — " Par quel secret mystere, Ce pain, cet aliment dans mon corps digere, Se transforme dans un lait douceraent pr^par^ ? Comment, toujours filtre dans ces routes certaines En longs ruisseaux de pourpre il court enfler raes veines ?" ** Demandez-ce k ce Dieu qui nous donne la vie—" Was the oracular answer. ** But what is the cause of my leanness ?" said a thin gen** tleman, who would have given half his fortune for half of my fat; ^* what is the cause of my leanness?" — "Demandez- ce d ce Dieu!" — ** Pho ! demand a fiddle-stick's end! — I want you to tell me, sir — you, sir ; — what is the cause of my leanness?" — ^* Well, — soyez tranquille — be quiet a minute: there is a predisposition in your constitution to make you lean, and a disposition in your constitution to keep you so." This explanation, about as satisfactory as Dr. Thomas Diaphoreus* explanation of the properties of opium — ** quia est in ea," &c. &c., did not soothe the irritability of my lean inquirer, who became^ if possible, more shrunken and wizened as his heat increased. Seeing the nature and temper of my antagonist, I went to book with him in another way :-^** Why, sir, as to the causes of leanness, there may be many that an ingenious theorist might suggest ; — I speak to you, sir, as to a sensible man.^' — ^The storm and heat began to subside j an oily word is 80 Lineaments of Leanness, like an emollient ; — ** I speak to you, sir, as a sensible man, and I am aware that it is not sufficient to talk to you in general terms, of constitutional peculiarities, digestive organs, and ali- mentary functions ; you must have a positive specific cause ; and, if possible, an explanation of that cause, as plain as the specification of a patent."" — " Just so ; that is what I want — you speak like a sensible man^^ — (the retort courteous) — » ^* Every effect, sir, must have a cause ; and I want to know whether the cause may be in the stomach, or any particular part of my inside, and if so, whether by particularly directing our attention to that part, wherever it may be, we can in any way alter its nature ?" The expectations of patients are sometimes very exorbitant, generally in proportion to their ignorance ; sensible people give very little trouble. Hence it is not difficult to satisfy these exorbitant demands ; for a foolish answer will always balance a foolish question. I do not recollect ever to have met the equal of this inquirer, except in a very pompous person, who kept a large circulating library, who doubtless thought ** keep- ing a library, he himself was learned," and who, Avhenever my answer satisfied his great mind, always expressed his appro- bation by a condescending nod, with — ** Aye ! now, sir, you give us a physical reason ! '* But *' revenons d nos moutons ;" finding my patient's mind was bent on localities^ I suggested the intestinum coecum for his consideration — the newly-discovered organ of fat ! He had never heard of it; this was what he expected of me ; (another retort courteous, for which I owed him one.) " This was news! What was it? how was it ?"— ** Why, sir, some are of opinion that the caecum contains a certain ferment, — some that it is destined to secrete an important fluid, — others take it for a second ventricle, wherein the prepared aliments may be stored up, and so long retained, till a thicker and more nutri- tive juice may be drawn from them ; — and how it is a depot of fat you will find in the ^ Philosophical Transactions.' " He heard this very attentively, and having passed mutual compliments, and being on very good terms with each other, he favoured me with his unreserved opinion. " I see very clearly, sir, the application of this discovery to my case : this is Lineaments of Leanness, tt an age of discoveries ! — the quantity of fat diffused over the body must be in proportion to the quantity in the depot : I must have a small coecum ! Now the question is — can we enlarge it ? — Perhaps I have no coecum !" We quite agreed upon the impossibility of supplying this defect ; but as " there is more in heaven and earth than we dream of in our philo- sophy," my philosopher did not like to relinquish all specu- lation upon the subject. I considered the case beyond surgery. I am not sure that I might have been allowed to look at the caput coli, — though I have known an operation done on almost as frivolous grounds. But when I told him that, according to the account of the celebrated Hoffman, dogs became rapidly fat when their spleen was removed, and that Mr. Hunter once removed it from a wounded man, who did very well, there seemed to arise a lurking longing, as much as to say, '' I wish Mr. Hunter had my spleen." There is an asperity in the acute angles of some persons, that gives a most forbidding appearance, — every feature is sharp, and every variety of movement quick. Shakspeare makes Caesar desire that he may have fat people about his person. It would be hard, on this authority, to condemn all persons who have the misfortune to be born with small coecums and large spleens, and are meagre from causes they cannot control, "as fit for treasons, stratagems, and spoils." Yet it is clear that Caesar liked a curvilinear embonpoint appearance in his body-guard, and thought there was most safety with a corpulent corps of household troops. The lean are not less exposed to ridicule than the corpulent. A reverend doctor of divinity, of very ghostly appearance, was one day accosted by a vulgar fellow, who, after eyeing him from head to foot, at last said, " Well, doctor, I hope you have taken care of your soul /" " Why, my friend," said the amiable shadow, " why should you be so anxious that I should take care of my soul?" " Because," rephed the other, " I can tell you that your body is not worth caring for." Jonas Hanway, who was remarkably thin, was met by a man much inebriated, who approached him in so irregular a direction, that it might have been concluded that he had busi- ness on both sides the way. Hanway stopped when he came JULY— SEPT. 1828. G tB Lineaments of Leanness, up to him, to give him his choice ; but the man stood as still as his intoxication would permit him, without attempting to pass on either side. After viewing each other a moment, •* My friend," said Hanway, '^ you seem as if you had rather drunk too much;^^ — to which the man replied, with consider- able naivete^ ** And you, my friend, seem as if you had ate too littler I have stated, that good humour and the power of looking on the favourable side of things are among the concomitant causes of corpulency ; and so they have been considered from the days of Solomon. — *^ A merry heart doeth good like a medicine ; but a broken spirit drieth the bones."— Prot;er 6s. Now the optics of some lean people are in so unlucky a perspec- tive, as to throw a shade over every picture that is presented to them : to them the whole face of Nature is gloomy and ugly. It would be a blessed thing for such persons, if Dol- lond could alter their vision by the aid of spectacles. To fatten a man by impressions on the optic nerve would be a new feat in the philosophy of physic and surgery. ** Laugh and grow fat" is an old adage; and Sterne tells us, that every time a man laughs, he adds something to his life. An eccentric philosopher, of the last century, used to say, that he liked not only to laugh himself, but to see laugh- ter, and to hear laughter. " Laughter, sir, laughter is good for the health ; it is a provocative to the appetite, and a friend to digestion. Dr. Sydenham, sir, said the arrival of a merry- andrew in a town was more beneficial to the health of the inha- bitants than twenty asses loaded with medicine." Mr. Pott used to say that he never saw the " Tailor riding to Brent- ford," without feeling better for a week afterwards. From what has been said, it will appear that, next to my phi- losophical patient's notions of enlarging the coecum, and less- ening the spleen, the excitement of laughter ought to have a a place in the '* Ars Pinguefaciendi." Mr, George Jones, mentioned by Granger, seems to have had this object in view in his ** Friendly Pills," which were to make patients of all com- plexions laugh at the time of taking them^ and to cure all curable complaints. Let us hope, for the sake of his Majesty's " lean lieges," that George Jones's recipe may start from some anti- Lineaments of Leanness, 6B quarian pill-box, for the engraissing and beautifying that por- tion of the population. Let us also flatter ourselves, that although we do not now know our way to Mr. Payne's toy-shop for his three-and-sixpenny bottle of" Pinguefying Specificj*' a specific will be found amongst the arcana of modern chfe-» mistry*. Amongst the most singular propositions for fattening the person, that our inquiries have furnished us with, that of flagel- lation is the most whimsical. In the " Artificial Changeling/' We read that the Mangones, to make their bodies more fat for sale, ** were wont to whip their posteriors and loins with rods, and so by degrees make them more fleshy ;" and it is even said that this is noticed by Galen, as no contemptible strata- gem to attract the nourishing particles to the outer parts. The operation of flagellation has been, in former times, re- sorted to by ecclesiastical doctors, as well as medical; and some very curious secrets were laid open in the Abbe Boi* leau's ^* History of the Flagellants." But the work most to our purpose is that of Meibomius, " De rUtilit6 de la Fla- gellation." *' Jerome Mercurialis," says Meibomius, "nousapprend que plusieurs m^decins ont ordonne la flagellation d des personnes maigres pour les engraisser, et leur donner de V embonpoint. •' Galien citant d ce sujet les stratagemes des marchands d'esclaves qui se servoient de ce moyen pour les faire paroitre plus brillans de fraicheur et d'embonpoint, ne laisse aucun doute sur I'efficacit^ de ce remade. II est certain qu'il fait gonfler la chair et attire d elle les alimens. Personne n' ignore que la flagellation avec des ortus vertes a le plus grand succes pour raffermir les membres et rappeler la chaleur et le sang * When the Spectator was first published in the form of a newspaper, advertisements were attached to it, of which the following is a spe- cimen : — •* An assured cure for leanness, which proceeds from a cause which few know, but easily removed by an unparalleled specific tincture, which fortifies the stomach, purifies the blood, takes off fretfulness in the mind, occasions rest, and easy sleep, and as certainly disposes and causes the body to thrive and become plump and fleshy, if no manifest distemper afilicts the patients, as water will (juench fire, &c. &c. ** It is pleasant to taste, and is sold only at Mr. Payne's toy-shop; price 3$, Qd, a bottle with directions," G2 84 Lineaments of Leanness. dans les parties qui en sont privees." — MeibomiuSy de VUtilitd de la Flagellation^ p. 33. He adds, — '' Combien de nourrices, sans avoir consulte Jerome Mercurialis, ni Galien, ont recours k ce stratag^me qu'elles connoissent par tradition, et claquant les enfans sur les fesses, avant de les rendre k leurs m^res, trompent par cet embonpoint factice et momentan^, la confiance des tendres parens qui leur ont confie ces interessantes creatures!" — Mei- bomiuSy de V Utilite de la Flagellation, One gentleman told me, that he understood mercury was very fattening. Mercury of itself cannot be said to fatten ; for if it fails to cure the disease for which it is adminstered, the patient becomes thinner. Those who refer all the difficulties to the stomach, and look for comfortable remedies in the '* Cookery-books," would do well to visit Paris, where a restaurateur invites patients of this sort, by the following consolatory exhortation written over his door: — Venite ad me omnes qui stomacho laboratis, et ego restaurabo vos ! This class of enquirers, who are generally great believers in the efficacy of milk, and cock-broth baths, gelatine, and po- tato-pie, and are ever on the alert to discover the most nutri- tious articles of food, should be informed of the notable ex- ample of the effect of chocolate, given by the industrious Dr. Mundy, who says that he knew a man in a desperate con- sumption, who took a great fancy for chocolate ; and his wife, out of complaisance, drank it often with him : the consequence was, the husband recovered, and the wife had three sons at one birth \—Harl. MSS. Notwithstanding the encouragement held forth by various remedial processes and specifics, the task still remains a diffi- cult one — and we must even now agree with what the learned Bulmer said a century ago, *' All bodies may be made leane, but it is impossible to fatten where vehement heat or driness is by nature ; for one may easily subtract from Nature, but to add to Nature is difficult, Avhen Virtue does not co-operate : all other creatures, if they have sufficient and proper food, will grow fat and befranked ; whereas men, although they have the best aliment exhibited to them, will not in like manner be fat, the chiefe cause whereof, as to man, is imputed to his tempe-* lomQnV^ '^Artificial Changeling, p. 478. 85 On the Curative Influence of the Southern Coast of England, especially that of Hastings. By William Harvvood, M.D. 8vo. pp. 326. London, 1828. Colburn. The subjects which the present volume embraces are very im- portant, and calculated, we conceive, to excite great interest m the mind of the general reader, to whom the work appears to have been addressed. Climate and medicine are each so powerful in their effects on disease, that we are often led to doubt which is the most active in its operation ; and situations, whose position or other local circumstances give to them an atmosphere of any pecu- liar character, are salubrious, or the contrary, though the causes are often concealed from our view, no great difference being found to exist in the chemical constituents of the atmo- sphere, wherever it has been examined. The present state of our knowledge, therefore, confines our investigations of its varied effects on the constitution, almost exclusively to the quantum of heat and moisture which it contains ; but even in these investigations we are far from finding ourselves free from considerable difficulties, since, in opposition to general princi- ples, we have to encounter the powerful influence of habit and peculiarities of constitution ; an atmosphere which, a priori, might have been supposed equally adapted to two individuals, being often found to suit the one, and not the other. It is, nevertheless, well known, that in many of the most formidable of our diseases, in whatever constitutions they may occur, a higher and more equally natural temperature than that which is usually enjoyed during the colder months of the year, is an important desideratum ; and it becomes, therefore, a question of great interest whether, all circumstances considered, it is, in the majority of instances, more safe to endeavour to obtain this equability and elevation of temperature in our own king- dom, among our own comforts and friends, or to lose the ad- vantages of the latter, by retiring to distant parts of Europe in its pursuit. In the former case it becomes an object of no less interest to the invalid to be made acquainted with the situa- tions which are the most likely to afford it, and what are the natural causes on which it may be supposed to depend ; and on this, as on other accounts, we consider the volume before us highly calculated to prove useful. The first part of the work relates to the temperature of coast situations, and it enumerates those circumstances which may be considered as affording to sheltered parts on our own 86 Curative Influence of the southern coast a higher and more steady temperature during the winter season, than any other portion of our island. These effects being chiefly derived from aspect, security from the effects of piercing winds, and from the influence which the temperature of the ocean exerts on the superincumbent atmo- sphere ; that of the surface water of the sea being greater dur- ing this period of the year, than the temperature of the sur- rounding air. Dr. Harwood remarks — that *' To account for this difference, it appears that the impressions of heat, which are imparted by the sun's rays to the surfaces of the waters, and of the earth, are disposed of very differently ; that heat which is received ©n the surface of the land, being slowly admitted, and feebly communicated to the dense earth below, loses much of its intensity by freely imparting it to the circulating air ; while on the contrary, such rays of light and heat as fall on the surface of the ocean, without this sudden check to their progress, penetrate the bosom of the deep to a greater or a less depth, in proportion to its transparency. Thus their limits are confined to a few fathoms from the surface, and their influence becomes gradually diffused through this upper stratum of water. From hence, probably, and from that law which ordains that the cooler portions of fluid should remain at a depth proportioned to their coolness, or that of their superior spe- cific gravity, the important result follows — that^during the winter half of the year, the temperature of the surface of the sea is greater than the mean temperature of the air, tending to produce, by the well known property which heat possesses, of equally diffusing itself through contiguous bodies, that equality in the latter, which can only be expected to be experienced, in this variable climate, in shel- tered situations on the coast ; situations which, like detached islands, consequently experience comparatively httle of that powerful change from summer to winter, which is felt on wide extended continents. Thus I may remark, that on the 8th of January last, when the ther- mometer stood at 35° on the Hastings' beach, I found it rise to 40^ on being introduced into the surface-water of the sea ; and on the 12th of February, the coldest day of the present year, when it stood, in the same situation, at 28°. 5, on immersion, it rose to 39°. "There is, however, another very efficient cause for the more ele- vated temperature of the ocean; I allude to the action of its cur- rents, and the succession of its tides, by constantly mixing and combining that surface-water, which has, in various latitudes, been differently affected by the solar beams. "Kirwan has given to the sea, between the latitudes 50^ and 51*^, which may be considered that of the south coast of England, a monthly mean temperature as follows : January. . . 42°. 5 April .... 52°. 4 February . . 44 .0 May .... 58 .0 March ... 50 ,0 June .... 61 .0 Southern Coast of England, €7 July 63^.0 October . . . 50°. August . . . 62 .0 November . . 46 .0 September ,.57.0 December . . 44 . I am, however, induced to think, that this calculation for the winter months is rather too high ; yet if we deduct 3 or 4 degrees for each month, still, the powerful influence which so vast a surface must exert in equalizing the temperature of a superincumbent atmosphere, will be necessarily admitted ; and this higher temperature of the pea, I may again remark, becomes, therefore, one demonstrable cause of the mildness of a coast climate, and one which could not be expected to operate equally far in the interior of the country. " Tlie effects of this cause in moderating the temperature of situa- tions differently exposed to it, are, therefore, well exemplified by comparison ; thus the temperature of Dublin compared with that of Warsaw — the one immediately influenced by that of the sea, the other probably very little affected by it, though both are nearly iii the same parallel of latitude, is as given in the subjoined note*". The effects of terrestrial heat, prevaihng winds, and cur- rents, on the temperature of our southern atmosphere, are next noticed ; and, in the succeeding chapter, Dr. Harwood proceeds to point out those peculiarities which justly place the Hastings' coast amongst the several situations on the southern shore, where the benefits of a mild climate, and other advantages afibrded by a proximity to the sea, are most ob- servable. To this end we are furnished with a notice of its topographical and leading geological characters, and of its North Mean Temp. Do. of Mean Extreme Lat. of coldest wannest annual ranere of Month. Month. Temp. the Mean. 530.21 37°. 6 60°. 3 48°. 4 22°. 7 >2 . 14 27 . 1 70 .3 48 .6 43 .2 Warsaw Petersburgh again, in lat. 59°. 56, from its situation, is necessarily but little influenced by the ocean, and we consequently find the range of the thermometer as follows : Mean of Warmest Mean annual Extreme range coldest Month do. Temp, of the Mean. 8°. 6 65°. 7 38°. 8 57°. 1 ButPekin, which is situated in latitude 39°. 54, or 20 degrees south of Petersburgh, probably from the important influence of the extensive Asiatic regions lying to the north and west, and the comparatively trifling equalizing power it derives from the Pacific, suffers a range of tempera- ture still more remarkable, as follows : Extreme range of the Mean. 59°. 4 North Cape, on the other hand, although having a latitude of 71° . 0, or 31° . 6 further to the north, from the influence of the ocean, by which it is almost surrounded, experiences a mean temperature, in its coldest month, of only 2°. 7 less than Pekin, it being 22^ . 1. Mean Mean Mean coldest Month. warmest Month. annual Temp. 24°. 8 84°. 2 54°. 9 6ft Curative Influence of the other more important features. Of the position of the town of Hastings, we have the following passage — *' Of all the benefits, however, which the Hastings' coast offers to the invalid, there is none more obvious than the choice of situation it affords, adapting it either for summer or winter residence ; many of its habitations being placed at an elevation of two or three hun- dred feet above the level of the sea ; consequently, as the tempera- ture of all places is so materially diminished in proportion to their elevation, that in this country, one of 270 feet is allowed to be equal in the difference of its temperature to an entire degree of latitude : and as these more elevated parts of the town of Hastings are more- over visited, during the summer months, by the then prevailing breezes, descending from the surrounding altitudes, these higher parts of the town necessarily receive from them a very diminished temperature, at those periods when coolness is most grateful. While on the other hand, the numerous habitations which are placed on the immediate beach, below the cHffs, being most effec- tually sheltered, at all seasons, from the more piercing winds, are no less suitably adapted for a winter residence. From hence it follows, that a proper degree of caution should be exercised on the part of invalids, lest by an injudicious choice, between situations so remote from each other in character, a summer or winter residence here, may lose some of its more important advantages. '* The most pernicious of all our winds, are the easterly and the north easterly ; the latter of which, in this valuable climate, is the only one which can be considered periodical, as it visits us with great regularity, during a greater or less portion of the months of April and May, which, from this cause, are usually trying months to delicate constitutions. " As, unfortunately, in no country in Europe are the pernicious effects of these winds more frequently experienced than in our own, it becomes of the utmost importance to observe, that such is the pe- culiar position of Hastings, that a considerable portion of it is most securely sheltered, by its natural bulwarks, from the searching and penetrating agency of these hostile winds. The more genial winds, on the contrary, which can alone visit these sheltered situations, are those which blow from the south, west, and south-west. Dur- ing the winter season they often prevail many days or even weeks together, sometimes very powerfully, and usually waft to our shores a very sensible increase of temperature. ** It will also, I think, be generally admitted, that few coasts are recommended by so much natural beauty as that of Hastings, as in this respect it possesses an acknowledged superiority over any other within a much greater distance from the metropolis, and is indeed almost the only situation in its vicinity, frequented by invalids, that combines great beauty of inland scenery, with that peculiar to an ejitensive and highly varied line of coast; which circumstance, in connexion with its extensive distribution of those sgurces of interest. Southern Coast of England, 89 calculated to excite pleasing and cheerful impressions, is of so much importance to the acquirement of health. In this point of view, however, the Hastings' coast is generally appreciated ; its surround- ing neighbourhood, consisting chiefly of fine pasture, interspersed with much woodland scenery, and affording on its numerous acces- sible elevations, the most extensive and interesting landscapes. These are at the same time intersected by fertile dells and romantic rocky vallies, whose shelter and peculiarity of situation afford, by the many rare species of plants they contain, a rich harvest to those who are interested in the vegetable productions of our island.'* Dr. H. has here subjoined a register of the temperature of Hastings, during the four last winter months, November, De- cember, January, and February ; and from this register it will be seen, to use the author's own words, ** That the coldest month we have experienced was February, which notwithstanding, I find, gives us a mean temperature of about 44° ; a striking example of the mildness of the late winter. A register of the same month in the year 1826, taken at Hastings, gives as the mean 43°. 5; but even this is perhaps rather higher than the coldest month generally. Baron Humboldt makes the mean of the coldest month in Edinburgh 38°. 3; Paris 35°. 1; and Rome 42°. 1. If, therefore, either of the former could be con- sidered as a fair average, our winter mean temperature on the southern coast would prove higher than even that of Rome." The work now assumes a more general character. Dr. H, proceeds to point out the more particular effects of various qualities of climate on the constitution of invalids, and he ar- rives at the conclusion that a climate which " is least liable to variation, and which unites a moderate degree of warmth, with a certain proportion of moisture, the usual properties of a sea atmosphere, is, in the generality of our afflictions, as conducive to improvement and health, as any to which we are exposed." This doctrine is satisfactorily supported in the elucidation which is given of the more obvious effects of other qualities in the air. The advantages which a sea atmosphere thus pos- sesses, is attributed to the little irritation it occasions to the lungs, and to its healthful influence on the exhalents of the external surface of the body, on which it tends constantly to keep up a gentle action, while it does not too rapidly deprive them of their fluids, or the body of its heat. In the chapter on the effects of climate, the author ob- serves, " This influence of climate, not only on disease already existing, but in its production or removal, as also in establishing its peculiar type, has been particularly noticed at all periods ; but by few has it 90 Curative Influence of the been more fully appreciated than by the great Hippocrates, who, in his labours on e})idemic disorders, has left us, amongst other treasures, his admirable and persevering example in accurately tracing its effects ; and indeed, the influence of atmospheric vicissi- tudes on the constitution, is one of the most important subjects of enquiry connected with the duties of the physician, from the great power which they exercise on the functions of animal Hfe. " The primary influence of the air which surrounds us, on the body, may be considered as resulting from a twofold operation : its action on the lungs, and that on the surface of the skin, and it is through the medium of each of these operations that its beneficial, or injurious properties, are imparted to the constitution. " The effects of the atmosphere also exhibit themselves in a strik- ing manner in the change of season, not only in the removal, but also in the production of diseases; and the same is not less ob- servable, as I have already noticed, under the prevalence of certain winds ; all which circumstances are highly interesting and impor- tant in a curative point of view." In noticing the effects of a cold and dry atmosphere, the author remarks, " The diseases to which this cold and dry state of the atmosphere chiefly predisposes, are inflammatory affections ; and it is more especially productive of rheumatism, coughs, catarrhal fevers, and inflammatory disorders of the lungs and chest ; all which are, there- fore, more frequently met with in high elevations than in the valleys. Jn such diseases, therefore, this kind of atmosphere becomes per- nicious, not only by the cold constricting the substance, and super- ficial vessels of the body, but by the irritation produced by its im- mediate contact with the vessels of the lungs ; and, by the same operation, from its power of quickening the circulation through them ; since the respective velocities of any fluid are inversely as the capacities of the canals through which it is propelled. " There is, however, another cause, which usually renders such a state of the atmosphere injurious to persons much debilitated by disease ; for as their afflictions incapacitate them from taking a sufficient degree of bodily exercise, the constricting force of the ex- ternal cold, becomes superior to the enfeebled power of the circula- tion ; and that of the exhalents on the surface, and the active func- tions of the latter, which are so conducive to health, become checked by the torpor thus induced, whence the whole frame necessarily sympathizes in the derangement. " An atmosphere, however, which is very cold, and moist, is far more generally prejudicial to invalids than the former ; for such a state of the air, so far from imparting appreciable advantages, is constantly succeeded by a great variety of disease. I have already observed, that the prejudicial influence of a cold and dry atmosphere on a debilitated system, although arising, in some degree, from the absolute abstraction of heat by contact, is chiefly communicated Southern Coast of England. 91 through the medium of its exhalent arteries, which, by the torpor they undergo, lose much of their energy, and consequently suffer a material diminution in the quantity of their secretion. ** When, however, cold is united with great humidity, a double cause operates in the production of this same result; for as the atmosphere can only sustain a certain portion of moisture in solu- tion, or mechanical union, the slowness of its absorption of hu- midity is necessarily in proportion to the quantity it has already acquired. A diminished or suppressed action, therefore, of the exhalent vessels of the skin, becomes here a still more certain result than in the former case, and more especially where bodily exercise cannot be enjoyed. " Another circumstance which tends to render a cold damp at- mosphere more prejudicial than a cold dry one, and more especially, than one that is calm, arises from its moreperfectpower of conduct- ing away heat, which Count Rumford, by numerous experiments, has shown to be the case ; consequently, although the thermometer indicates the temperature to be the same, still its effects on the constitution are widely different ; and debilitated persons feel more chilled by such an atmosphere, at a temperature of 35°, or 36°., than when the thermometer is down at 31° or 32°. '* Such an atmosphere, then, even on those who are naturally healthy, if it long prevail, can scarcely fail to be productive of more or less derangement of the bodily functions ; which derangement is generally evinced by depression of spirits, indisposition to exertion, and most commonly, a sympathetic torpor and inactivity in the di- gestive function in its general sense ; with vitiated or impaired se- cretions of the liver, and other glands. *' I have before observed that such an atmosphere as combines moderate warmth, with a slight degree of moisture, is, in the gene- rality of diseases, perhaps more conducive to improvement than any other ; yet, there is not probably a more baneful combination than when great heat and moisture are conjoined, and, more especially, when the air is at rest. This is too fully exemplified to us by its pernicious effects in tropical countries ; where the air, in low and marsliy districts, when confined and rendered stationary by woods, and consequently united with the unhealthful influence of perpetual vegetable decomposition, is productive of the most serious conse- quences to all who are exposed to its influence. '* The effects of an atmosphere thus surcharged with heat and vapour, on the constitution of man, is to relax the solids, to rarefy the fluids, and to increase the secretions on the surface ; which, however, from the already saturated state of the air, is not readily removed ; to lessen the powers of the circulation, and to diminish the energies of the body, giving rise, by their combination, to the various awful epidemic diseases, to which, fortunately, we are little exposed in this island. ** Yet, that a certain degree of moisture is necessary to constitute 92 Curative Influence of the a healthy and restorative atmosphere, is evident, from a considera- tion of the deleterious effects of one without it ; for air, destitute of moisture, cannot be breathed with ease or impunity, whether it be warm or cold; when any degree of irritability exists within the Iun£^s, such an air generally becomes insupportable, and when united with much heat, is to all, productive of great oppression and uneasiness, as is experienced by those whose occupations expose them to its influence; while, on the contrary, if humidity be added to it, such impressions are speedily removed. It is, therefore, a common practice among such as are exposed to air greatly heated, by means of stoves, to have recourse to steaming the apartments. " From such considerations then, may be I think deduced, the superior advantages which are afforded in many diseases, by a sea atmosphere, little subject to these extremes, advantages arising, not more from the absence of the irritation they occasion to the lungs, than from its heahhful influence on the exhalents of the external surface of the body ; on which it tends to constantly keep up a gentle action, while it does not too rapidly deprive them of their fluids, or the body of its heat. *' The salutary and invigorating qualities, however, of sea air, which have been so long experienced and acknowledged, have led to the idea, that other causes have an important share in the pro- duction of its peculiar effects ; and thus they have been assigned to a difference in its chemical composition, from that of the land, while other authors, as Dr. T. Reid, have been contented to regard it as * the most pure and healthful we possess,' without allusion to the causes which impart its salubrity. It is well known, however, that saline particles are wafted by it to considerable distances, and M. Vogel, of Munich, has shewn inapaper, published in the JowrwaZc^e Pharmacie, No. 11, for Nov. 1823, that the sea air of our channel, holds in chemical combination, a portion of those muriates over which it is wafted, and a less proportion of carbonic acid than that of the continent of Europe. '* One quality of vast importance to its salubrity, is, doubtless, its constant agitation ; by this means it affords to us, at each inspi- ration, a regular supply for our demands, pure and uncontaminated by noxious effluvia." The next thirty or forty pages relate to the effects of warm and cold sea bathing on the constitution, and the circum- stances which render it inadmissible. Dr. Harwood then proceeds to take a comprehensive view of those maladies in which he conceives the operation of coast advantages to be most important, viz., various diseases of the chest, as consumption, winter cough, and asthma, indigestion, acute and chronic rheumatism, gout, the effects of loss of blood, and of other debilitating causes, and of mercurial me- dicines, diseases of the liver, scrophula, and many disorders incident to children. Southern Coast of England. 93 This part of the work, which is by far the most voluminous, is executed in a manner which reflects highly on the profes- sional talent of the authors, and exhibits a very extensive ac- quaintance with the opinions of ancient and modern physicians, on the broad basis of whose established opinions, rather than on novel hypotheses, he has, we think very judiciously, rested the reputation of his work, in support of the arguments he adduces. Although it is diflicult to make a selection from this useful part of the publication, a few extracts may serve to illus- trate the perspicuous style in which it is written ; and with these our limits will compel us to conclude our notice of a work, which, from the importance of the subjects it embraces, and the mode of treating them, must be considered a valuable acquisition to the public. In the Chapter on Consumption, Dr. Harwood observes, in reference to low situations, " Low situations having been found less obnoxious to consump- tive complaints, and, on the contrary, a diminished atmospheric pressure, whether depending on meteorological variations, or on a removal from a lower part of the kingdom to one of a higher level, being thought to be prejudicial in such cases, many medical authors have supposed the advantages of the coast to be materially aided by the increased weight of its atmosphere. " It has, indeed, not only been observed, that the proportion of these diseases materially increases as we ascend from a lower to a higher elevation, but cases are recorded in which their progress has been effectually arrested by a removal thence to a lower level. " That such results, however, are dependent entirely on the de- gree of pressure to which the lungs are subject, is not clearly de- monstrated ; since the pernicious influence communicated, on high elevations, to pulmonic diseases, may arise, in a more especial manner, from the greater vicissitudes of heat and cold to which such situations are exposed ; although I conceive that there is evi- dence amply sufficient for believing, that the greater or less degree of pressure in the atmosphere, is productive of very important effects on organs so immediately exposed to its action, and ren- dered by derangement or disease, preternaturally sensible to its effects . ** This would appear more particularly apparent from the obser- vations of Mr. Mansford, on the degree of acceleration which the pulse acquires even at a comparatively trifling elevation ; for, on ascending no more than 500 feet above the level of the sea, it seems that the heart gains an accession of several pulsations per minute ; while the resistance of the vessels is diminished in an equal pro- portion, as is demonstrated by the well known circumstance, tliat even the most healthy persons, on ascending great heights, not un- 94 Curatke Influence 0/ th6 frequently experience a rupture of small vessels, which are distri- buted on the membranes most exposed to these influences ; it is therefore easy to conceive, that injurious consequences may result from slight elevations, to invalids, the delicate vessels of whose lungs have either suffered partial disorganization, or have acquired an increased degree of susceptibility to disease. ** This increased rapidity in the circulation, and in respiration, is, nevertheless, by no means proportioned exclusively to the degree of elevation to which the individual is exposed, but is not less affected by constitutional peculiarities ; hence evidently the cause, why so much discrepancy exists between the accounts given by authors, of the sensations they have experienced at different altitudes. " Thus, although M. Saussure informs us, that on ascending Mont Blanc, he suffered from these effects in a very high degree, that his strength became exhausted, and that various febrile symp- toms evinced themselves ; and although Sir W. Hamilton felt great difficulty in his respiration on Mount Etna, and many have been attacked by haemoptysis and other haemorrhages, under similar cir- cumstances ; Dr. Heberden did not complain of any very material inconvenience from visiting the Peak of Teneriffe, and the same may be observed of several others, who have reached the heights of Mont Blanc and parts of the Andes ; and even Of those who have experienced the rapid ascent of balloons. " But, notwithstanding these facts, when we consider, that in low situations, and with the barometer at thirty inches, we sustain an atmospheric pressure of fifleen pounds upon every square-inch, or thirty-two thousand pounds weight on the whole surface of the body, elevations, great or small, as well as changes in the state of the atmosphere, by each of which, this external pressure is often suddenly diminished several thousand pounds, necessarily exert a powerful influence on the delicate structure, and functions of the lungs, when the health of these organs is in any way deranged. " From various experiments, which have been at different times undertaken, with a view to determine the effects produced by a light, and a heavy atmosphere on the function of respiration, we learn, that, although animals become subject to such serious incon- venience from the partial exhaustion of the air, within the receiver of an air-pump ; on the contrary, by the condensing machine, they sustain a degree of pressure equivalent to the weight of three or four atmospheres, without apparent injury ; and that, after an ani- mal has been subjected to this extreme pressure, it seems to expe- rience the most uneasiness in returning to that of its accustomed medium. *' In the first instance, there can be little doubt that the incon- venience does not depend more on the primary abstraction of the air, and the scanty supply of oxygen which so rare a medium can afford, than on the suffocating effects produced by the distension of the blood-vessels lining the minute air-cells of the lungs, by which Southern Comt of England. 95 the latter become diminished in their capacity ; the absolute volume of air received, beinfr small, in proportion as it is rarefied. *' In proportion also to the existing weight of the atmosphere, is the quantity of oxygen, which passes into the lungs, and there ap- propriated to the important end it is destined to fulfil in the animal economy ; and the necessity for a quick succession of inspirations is diminished in the same ratio ; while, on the contrary, respiration acquires equally an increased rapidity on high hills, and in air deteriorated by frequent inhalation. ** Dr. Wells took unusual pains to ascertain the influence of situation on consumption, and he has adduced many examples in corroboration of the comparative rareness of the disease under a heavy atmosphere. He remarks, that he was led to undertake this enquiry, from having heard, so long back as the year 1779, that it was common in Flanders to remove the consumptive to the low and marshy parts of the country for their benefit. Mr. Mansford has also collected numerous instances of the greater prevalence of con- sumption in high, than in low situations, and Drs. Darwin, Cullen, Beddoes, and others, have consequently advised the removal of in- valids liable to this disease, from the higher to lower parts of the country ; and this practice is more or less common in most king- doms where the disorder prevails. *' At Aix la Chapelle, consumptions are said to be very rare, while at Monjoye, a mountainous country, only twenty-eight miles distant, this disease carries off a large proportion of the inhabitants. it is also said that the hill of Montmorency, near Paris, which is dry, sandy, and much exposed, is very productive of consumptive disorders, and that those who visit it, with any predisposition to these complaints, almost invariably derive unfavourable effects from the change ; and the same remark applies, with no less certainty, to many of the hilly parts of our own country. " The inhabitants also of the mountainous parts of Portugal and Italy* are very subject to consumption, while those of Finland, Den- mark, and Holland, are much less liable to its attacks. *' There is, consequently, amply sufficient reason for supposing, that it is partly from causes of this kind, connected with a greater degree of exposure, that this disease has been found to be less common in low situations than in any other. This circumstance has given rise to the idea that consumption and intermittent fevers, cannot exist to a great extent in the same district; which latter opinion is, nevertheless, erroneous, as they are not only found in the same situation, but even in the same individual. " Although, therefore, there is no sufficient reason for making choice of those more marshy districts which have been selected, on the continent especially, for consumptive patients, notwithstanding their tendency to produce intermittent fevers, we ought not to disre- gard the benefits arising from an increased weight of the atmosphere, in those situations where the latter disease need not he encountered* 96 . Cufatlve Influence of the On the subject of sea air in consumption we have the fol- lowing observations, — " But although the genial properties of a sea atmosphere to constitutions generally, is, I believe, fully acknowledged ; it has been lately doubted, by certain physicians, if it be as well adapted for consumptive habits ; and this being an inquiry of so much im- portance in reference to a residence on the coast, in these cases, de- mands further notice. " That a sea atmosphere is less conducive to the production of consumption, than any other, may, I think, be inferred, from many of those kingdoms which are most exposed to it, being the least subject to the disease, as is particularly the case with Denmark. In the islands of the Mediterranean also, as in Malta, Minorca, and all those of the Grecian Archipelago, we are told, by Dr. Southey, and other authors, that consumption is of very rare occurrence. " On the Alexandrian coast, it appears to be altogether unknown; while at Aleppo, which has an intermediate latitude, but which is situated at a greater elevation, and is more distant from the sea, it is said, by several writers on the disease, to be very prevalent. It is also a well known fact, and particularly mentioned by Dr. Trotter, in his Medicina Nmitica, that consumption very rarely occurs in seamen, except under peculiarly unfavourable circumstances. " That this disease is, nevertheless, too often met with on our own coasts, is equally certain, though it is there less prevalent than elsewhere ; and it usually arises under the combined influence of crowded towns, a bleak and exposed aspect, and great humidity of soil, or under exposure to cold winds from neighbouring mountains ; it is said also to be very common in the interior of the island of Iceland, but much less frequent on its coast. *' The advantage of a sea atmosphere, in those cases where this complaint already exists, is best inferred from general experience ; and the most satisfactory proof of its adaptation, may be deduced from the numerous ages in which its benefits have been sought. " Aretaeus, who lived almost 460 years before the Christian era, is, I believe, the first who recommended sailing and a sea atmosphere in consumption : and although so many centuries have rolled away since his time, and so many publications concerning this disease have appeared, we find very few individuals who dissent from his generally received opinion. " Dr. Duncan observes, that he has not seen, in his practice, any thing which tends to confirm the idea that sea air is injurious in consumption, and he recommends a residence on the coast ; and, among many others, Dr. Gilchrist has published cases in which the greatest benefit has resulted from the effects of sea air." In speaking of winter cough, Dr. H. remarks, ** From the whole character of the disease, therefore, it is suffi- ciently evident that the only effectual and reasonable mode of avoid- Southern Coast of England, 9t ing its consequences, consists in combining, as far as possible, the effects of an equable and elevated temperature during the winter months, with those means which are best adapted to impart strength ; thus enabling the constitution to contend against the in- fluence of the disorder. The advantages of pursuing such indica- tions are not only exhibited by daily experience, and their adoption strictly enjoined by all the best writers on the subject, as Dr. Bad- ham, Dr. Beddoes and others, but they have, I trust, been rendered sufficiently obvious in the preceding pages, to require very little in addition to what has been already observed. ** Although material benefit, in these cases, may be constantly derived from a careful attention to the degree of heat employed within doors, yet, as Dr. Buxton has very justly remarked, * where a natural elevation of temperature can, without difficulty, be ob- tained, it is infinitely preferable to an artificial one,' as the invalid, in the former case, can adopt additional means of recruiting his health and strength, and chiefly, by exercise, in a pure and moving atmosphere ; which very material advantage he is necessarily pre- cluded from enjoying, during a confinement to his room. *' Although we cannot reasonably expect the perfect union of the most favourable of all natural means, in our own kingdom ; yet, as there are situations which approach this combination so much more nearly than others, their influence may always be sought by patients suffering under these complaints, with the greatest relief and benefit. *' This remark of course applies, with almost equal force, to all the more sheltered situations along our southern shore, where, from causes already enumerated, the thermometer is necessarily much less liable to variation than in any other part of England ; and where, during the more severe seasons, opportunities so frequently present themselves of taking exercise under the protection of the cliffs, and within the reflected influence of the sun's beams." The utility of exercise in gout is thus enjoined by our author. *' So various are the modes by which this important antidote exerts it beneficial influence, that it would be tedious to enumerate them ; I shall, however, briefly notice a few. By the stimulus it affords to the circulation, it increases the energies of the exhalents on the surface of the body, and, consequently, the volume of insen- sible perspiration ; and, without expense of animal strength, if pro- perly employed; it thus diminishes the mass of the circulating fluids. " By the sympathy existing between these exhalents and the sto- mach, an influence no less beneficial is communicated to this organ, tending to impart a healthful action to its function. The salutary operation of exercise on the alimentary canal also, in increasing and preserving its peristaltic motion, with the effects on the viscera derived from the action of the abdominal and other muscles, as before shown, is of the highest utility. JULY—SEPT. 1828. H ^ • Curative Influence of the " Exercise not only prevents the formation of those concretions which are frequently deposited around the joints in gouty disorders, but it enables the absorbents more readily to remove such as may already exist. It tends also to preserve that motion in the limbs, which is too liable to become impaired or destroyed by contraction of the tendinous structures in this disease. " It is, moreover, an important means of correcting that acidity, which is almost an invariable attendant on derangement of the di- gestive organs, but more especially in gout, in which disease even the cuticular discharge is found by the chemical changes it produces on vegetable colours, to be of an acid nature ; this beneficial ope- ration it probably effects by increasing, not only the action of the exhalents, but also the flow of bile into the alimentary canal, which bile may directly tend to neutralize the existing acid, by its alkaline properties. " To produce these useful effects, the exercise employed should be moderate, but it should be pursued with great perseverance during the absence of the paroxysm ; no day being allowed to pass, without having recourse to it, when the weather and other circumstances will permit." In the introduction to the diseases of children, are the fol- lowing observations, — " In many of the diseases of children, I am particularly anxious to call the attention of the reader to coast advantages, from the in- valuable influence they are capable of imparting; and not less, from the conviction, that such benefits are too often overlooked by parents, who, in their tender solicitude, anxiously expect, from me- dicine alone, that aid, which can only result from the union of the most powerful means which nature herself has afforded. *' Independently of more humane considerations, the important effects which the disorders of childhood produce on the health and well-being of society, enforce the necessity of combining every pos sible advantage in their favour ; yet I am convinced, that to the unfortunate neglect of the more natural remedies, and the resort to such only as are more readily attainable, may be attributed the de- velopment of many of those chronic diseases, to which we so often see youth subjected ; and which, in later years, are injurious, no less to the comfort, than to the prospects in life, of the individual. " The constitution of children renders them not only more sus- ceptible to those external circumstances, connected with peculiar locality, which are productive of disease, but imparts to them the capability of deriving more speedy and greater benefit from natural sources, than is commonly possessed in after life ; and, although, in every stage of existence, a pure and wholesome atmosphere tends so materially to the acquirement and enjoyment of health, to the young, this is far more essential ; whilst every other means of con- tributing to its insurance, is no less imperatively demanded by them. Southern Coast of England* ^tSf . ** These observations are supported by the fact, that during youth, the various functions employed in supplying nourishment to the body, are far more active than in the after periods of life, having now a double duty to perform, not only to sustain organization already existing, but to extend and mature it ; whilst, on the con- trary, in succeeding years, a supply, for the waste which results from constant action and employment, is all that is demanded from the functions of nutrition. *' As food is the source whence the nourishment of the body is derived, so the air, by the change it produces on this nourishment, through the medium of the blood, adapts it to the purpose of sup- porting our existence; the mutual operation, therefore, of food and air, in effecting the important process of nutrition, it being impos- sible that either should duly perform its office, without the perfect co-operation of the other, renders it evident, that pure and whole- some qualities in the atmosphere are as essential to the healthful development of the body, during youth, as the same qualities in the food which is employed. *' The constitutional demand for food is made known to us by feelings which cannot be mistaken ; and, in childhood, these are even still more powerful and frequent, than in later periods of life. " The want of wholesome air, however, does not manifest itself on the system so unequivocally, or imperatively, no urgent sensation being produced comparable to that of hunger, and hence, the greater danger of mistaking its indications ; the effects of its absence are only slowly and insidiously produced, and thus, too frequently, are overlooked, until the constitution is generally impaired, and the body equally enfeebled. " A child so circumstanced, although it neither suffer from pain or fever, loses the ruddy appearance of health ; its countenance be- coming pallid, and acquiring a certain anxious expression ; it often ceases to grow in proportion to its years, and a degree of listless^ ness, and a morbidly increased, or a diminished appetite for food prevails; until, if recourse be not had to the only rational remedy, that of a removal to a more salubrious situation, disease, in some positive form, creeps on, as the natural result of this state of priva- tion ; as may be so constantly observed in those, naturally, healthy children, which reside in crowded and confined situations." We fully coincide with Dr. Harwood in the belief that the efficacy of sea water is too much overlooked as a medicine in the present day ; we shall, therefore, subjoin also his observations on its utility in scrofula. ** These disorders are frequently combined with an habitually confined state of the bowels, which greatly favours their progress, and impedes their cure ; and this condition seems, sometimes, to be -connected with constitutional fulness of habit. H 2 SroO On Ornamental Aviaries. ** In all such cases, purgative or aperient medicines become especially requisite ; and in the latter capacity, sea-water, which, from the earliest ages, has been esteemed an important remedy in these complaints, may be administered with very great advantage ; the intention, generally, being not so much to produce a powerful operation on the alimentary canal, as one which is gentle, and con- tinued, by which the action of the biliary and other secreting organs, may be regularly and mildly assisted. *' There are no purgative medicines, even of the most simple kind, whose use can be better regulated than sea-water ; and there are none, whose frequent employment is less likely to be followed, either by languid action, or by that state of constitutional excitement, or, I may add, inflammation, which, not unfrequently, succeeds the too frequent use of more powerful purgatives. ** Calomel, notwithstanding its advantages, is, nevertheless, a medicine of this kind; for although, in these, as in so many other complaints, it is one of the most useful and eligible that can be em- ployed, not more from its purgative, than from its other properties, it is yet one whose use cannot, with propriety, be very frequently repeated, or long persevered in. It is therefore an important con- sideration, that the peculiar properties of sea-water are such, as to allow of its more constant exhibition, either alone, or in alternation with calomel, or with other medicines, whose peculiar properties may indicate the utility of their employment." We cannot, indeed, conclude the analysis of the work be- fore us, without expressing our approbation of the clear, sen- sible, and temperate manner, in which it has been executed, and our high sense of the many valuable observations it con- tains. On Ornamental Aviaries, It is not a little surprising, that while every villa, and almost every cottage, has its greenhouse, or conservatory, compara- tively few, even of our most splendid mansions, can boast of a well kept aviary ; and yet, to the lover of natural history, or even to the mere admirer of animated nature, the latter is sure to afford constant amusement and gratification ; and, in point of expense, its first cost is not so great as a conservatory, nor is the keeping it up more expensive; for while the one requires the constant attention of an experienced gardener, the wants of the other can be supplied by an old woman, or a boy 3 and On Ornamental Aviaries. 101 the expense of seed will not amount to more than the differ- ence in wages. Some humane minds Iiave objected to an aviary, from a dislike to deprive the inmates of their liberty ; this is, however, an objection more specious than real. Those who have directed much attention to the habits of animals, will confirm me in the assertion, that even birds, who have the power of locomotion to a greater degree than other animals, make excursions principally for the purpose of obtaining food; and I have observed the same pair of bullfinches on the same hedge, and started them within a few paces of the same spot, day after day, for many weeks ; and that in winter, when it could not be from the attraction of their nest. I found a pair of hedge-sparrows had taken leave to enter my aviary, and, for some time, was unable to discover how they had gained admittance ; but they had found a defect near the roof, through which they could enter, and they took advantage of it. They occasionally went out, but never to any distance ; they natu- ralized themselves to the place most completely, and had a nest of eggs in the aviary. I believe if animals have plenty of food, and suflicient room for exercise, they require and desire no more. If, therefore, the proprietor of an aviary consults the habits of the birds he places there, and supplies them with appropriate food, he affords them ample compensation for the gratification they afford him, when hearing their lively song, and observing their sprightly movements ; of course, there is great difference between the freedom of an aviary and soli- tary confinement in a cage. Few improvements have been made in the construction of aviaries, because few have ex- pended property or pains in erecting them. The site of an aviary should be facing the south or west, and sheltered from the north and east. It should be principally open to the air, and should be constructed of wire almost entirely. But there is no objection, indeed it is rather desirable, that some parts of it should be covered with a roof affording shelter in winter, and shade in summer. A constant supply of fresh, and, if possible, running, water is exceedingly necessary for the health and comfort of the little inmates. The aviary should be well covered all over with turf, excepting the walks, which should 102 On Ornamental Aviaries. be gravel. The perches should be most of them over the walks, for the facility of cleaning ; and ample cover should be afforded by evergreens, such as the phyllerea, ilex, holly, laurel, Portugal laurel, laurustinus, yew, box, cypress, &c. If deciduous trees be planted, the leaves will soon be picked off, and the buds destroyed. If it should be intended to include foreign as well as native birds in the aviary, it should be so con- structed as to be capable of being heated in the winter ; and the best mode of doing this would be to have the aviary fronted with glass four or five feet from the wires, and the space between ornamented with plants, both because they would afford the best test of a proper temperature being maintained, and also this would combine the sources of gratification and amuse- ment. Should only a few foreign birds be admitted, separate apartments may be so constructed, as to communicate with the aviary in the summer, and to be shut up and warmed with a flue in the winter. This is necessary even for the canary- bird, which is too delicate to bear our climate without suf- fering ; excepting those green birds, which appear to have been less affected by domestication. In the gallinacii, no- thing is so likely to preserve them from that fatal malady, the roup, as constant supply of fresh water. This disease has been shown, by Mr. G. Montagu, to be owing to a species of fasciola, which fixes to some part of the trachea, and which multiplies to such a degree as to cause death, either from suffocation, or, as seems to me, by inducing inflammation of the membrane of the trachea. That this theory of the disease is correct, is confirmed by my own observation ; and I am, moreover, convinced, that the disease is generally induced by inattention to giving the young birds a supply of fresh water. I have little doubt, that the fasciola producing the disease is generated in stagnant or putrid water, and have found the best mode of preventing the disease was to have the vessels cleaned by scowering, or throwing in hot lime, every two or three days. Mr. Montagu recommends soaking the food in wine ; I cannot say I have found this remedy answer iny expectations. I know a farm-yard where the housewife is a most caFeful attentive woman, but she complains she can On Ornamental Aviaries. M3 keep none of her chickens, on account of their being attacked with the roup. On examining the yard, I found the poultry were in the habit of drinking at a horse-pool, which received the drainings of the pigsties and ox-stalls, and this appeared sufficient to account for the prevalence of the disease. I found my young brood of pheasants and partridges always did well till they were shut up in my poultry-yard, or aviary ; and as soon as that was the case they began to suffer from the roup. But to return to the aviary — birds are either carnivorous, granivorous, or insectivorous *. The first class are not fitted for the aviary — the second always do well — the third re- quire great care to keep them in health. I have found that the best food for constant supply is buck wheat, hemp, rape and canary seeds, and a mixture of barley meal and grated liver. The latter is particularly necessary for the lark tribe and the Sylvias, and also for the merulidae. Snails, slugs, and worms, should be frequently supplied also ; and green food, such as groundsel, chickweed, lettuce, and water- cresses ; also the seed of plantain, dock, and thistles occasionally. The seed should be provided in boxes, so constructed that a little only should fall down at a time. There should be several boxes, as the stronger birds are apt to tyrannise over the weaker, and keep them from their food ; and each of the boxes should have several divisions of wire, or wood. The enemies of the aviary are numerous : of these the cat is the most formidable ; they will sit on the roof of the aviary for hours in a moonlight night, alarm the little inmates, and then pounce on them as they fly towards the light, and against the wire. I have sometimes found three or four birds in a morning killed by the cats, sometimes the head torn off, but often entire, * These may be subdivided into those which live almost entirely on the wing, and whose food consists of those insects which they meet with flying, or those which hve on the larvae or eggs of insects which they meet with on the ground. The former are quite inappUcable for the aviary ; for, independent of their being migratory, it would be impossible to supply appropriate food — the food of the latter may be afforded or imitated. 104 On Ornamental Aviaries. but pierced with the claws, and killed with terror. The wires of the aviary should not be more than half an inch apart, both to secure from this enemy, and also from that formi- dable one the stoat, or common weazel. The aviary also suffers much from rats and mice, the latter especially mul- tiply exceedingly, from the abundant food they obtain ; to prevent this as much as possible, the food should always be supplied in the boxes I have described, or on a table on a single pedestal. I had a circular tin-case, with holes at inter- vals all round ; this was supplied by a large central box, from which the seed dropped down into all the partitions, so as to keep a constant moderate supply ; this, supported on a pe- destal, is not inelegant. I will now shortly enumerate the birds most fitted for an aviary : of course, none of the genus falco or the genus strix can be inmates of the aviary ; they are very pretty appendages to it, however, if they are braced and chained to a stand. I have kept the kestrel and the martin in this manner, and they are beautiful specimens of their kind. The genus lanius is also inadmissible ; of the picae, the jay is a pretty ornament, but too mischievous to be at large in the aviary ; the other species are not sufficiently ornamental to compensate for their mischievous propensities. I have never possessed the chat- terer, ampelis garrulus — it would, doubtless, be a great orna- ment to the aviary. There is a bird, which I have kept only for a short time, but which, I doubt not, a little pains and per- severance would preserve, and a beautiful ornament it would be to the aviary, viz., the kingfisher. There have been in- stances of this bird being rendered very tame, and if the stream which supplies the aviary were stocked with minnows and gudgeons he would be sure to thrive. The creeper is a very gentle little bird, and easily kept. Of the passeres, the star- ling is a handsome and very amusing bird ; but his habits are so bad, and he is so destructive to smaller birds, that he cannot be admitted as an inmate of the aviary, except in a distinct apartment. The genus turdus is the great pride of the aviary : they are easily kept, soon become domesticated and familiar, breed most freely, and repay you by their song On Ofimmenfal Aviaries. 105 nine months in the year. I have had many generations born in my aviary : they require an abundance of snails and worms during the breeding season. The most beautiful are the Turdus Viscivorus Missel Thrush — — Musicus Song Thrush Merula Blackbird Torquatus Ring Ouzel — the three first are the only ones 1 possessed. Of the genus loxia, I have kept only the Loxia Curvirostra Cross Beak Pyrrhula Bullfinch Chloris Greenfinch ; but they may all be kept with great facility. The loxia cur- virostra, the cross beak, is very ornamental and amusing ; but their beak is an instrument of great mischief, and they com- mit much havoc by barking the trees, and destroying the wood- work of the aviary. The other members of the genus are easily kept, and the loxia pyrrhula, or common bullfinch, is one of the most beautiful of the inmates of the aviary. It is scarcely possible, however, to keep more than one pair, unless the aviary be very large, as they fight during the season of love with most unrelenting pertinacity. The genus emberiza are easily kept; but I have only had one species, viz., embe- riza citrinella, or yellow hammer, a very pretty bird, although its note is rather unpleasant. The genus fringilla is the chief ornament of the aviary : of these I have kept specimens of the following, without any difficulty, for a very long time, viz., Fringilla Domestica House Sparrow Montana Tree Sparrow Coelebs Chaffinch Montifringilla Mountain Finch Carduelis Goldfinch Spinus Aberdivine Cannabina Linnet Linaria Redpole Montium Twite Can aria Common Canary Bird. These birds all breed in the aviary, and by their familiarity JOS On Ornamental Aviaries* and their lovely notes amply repay us for our trouble. They are too, almost all of them, gregarious, and many specimens of each kind may be kept in the same aviary ; they are all of them granivorous, and only require a good supply of greens daily, to keep in perfect health. The genus alauda are kept with more difficulty, but they thrive well on barley meal and grated Hver. They often suffer from the mice, who destroy their eggs, and sometimes even themselves, when roosting on the ground ; of these I have only kept, Alauda Arborea Woodlark — Arvensis Skylark Pratensis Titlark. The genus Motacilla is easily kept, and the motacilla flava is one of the most elegant birds that are found in this island. It is a graceful and familiar little creature, and its colour very beautiful and ornamental. The genus Sylvia is kept in the common aviary with great difficulty ; the greater number of them are migratory, and their food principally in- sects. They require a regulated temperature in winter, and insect food, which at that season is very difficult to obtain. The perseverance of Mr. Sweet has been rewarded by the do- mestication of many of them, and the beauty of their song, and the elegance of their movements, is sufficient incitement to make the attempt. They will, however, almost all of them, require a separate apartment. The following will succeed very well in the common aviary, and I have kept them very successfully on the common food of the aviary. Sylvia Modularis Hedge Warbler Rubecula Redbreast Troglodytes Common Wren Regulus Golden-crested Wren. These are very pretty inmates for the aviary. It will be scarcely possible to keep more than one pair of the redbreasts, as he is quite master of the place, beating birds twice his size, and prying into every thing which is placed there ; they are most prolific ; but it is almost impossible to be sure of getting a pair, as there is but the slightest difference between the cock and the hen. On Ornamental Aviaries, 107 Of the genus Parus, the parus major, or great titmouse. — Parus coeruleus, or blue titmouse, are easily kept, and are very pretty birds. I have myself kept none others of the family. Of the coluraba, the columba turtra, turtle-dove, and se^ veral foreign inmates, may be kept perfectly well, and they are exceedingly prolific, gentle, and easily domesticated. There is a white variety of the common Barbary dove, (which is common all over the south of Europe,) which is a very ele- gant and beautiful variety. The gallinacii are, perhaps, better kept in an open poultry-yard than in the aviary, except the gold pheasant, which is a proper appendage to it, and is to- lerably hardy; but the silver and common pheasants, pi- nioned by having the last joint of the wing cut off when they are young, do better with a larger range than the aviary affords. The genus perdix, however, are very pretty birds for the aviary ; as the Perdix Cinerea Common Partridge Rufa Redlegged Partridge Coturnix or common Quail, but the latter are too delicate for this climate in general. The only other bird I shall mention, as suitable for the aviary, is^ the tringa vanellus, or common peewit, which feeds very well on bread crumbs, worms, and other insects. I have thus enu- merated most of the varieties of our British birds, which are ap- propriate for the aviary. The continent of Europe and North America afford many beautiful specimens which would live in our climate ; and if the taste for ornamenting the aviary were pursued with half as much zeal as for making acquisi- tions for the green-house, the varieties would, indeed, be great, and the pains well repaid ; and if the aviary were con- structed with only moderate regard to preserving equal tempe- rature, such as is sufficient for the ericae, proteae, acacise, &c. &c., our aviaries might contain the most splendid speci- mens of the merulae, tangarae, cotingae, &c., a far more inte- resting mode of preserving them than as stuffed specimens. It is to be hoped that the aviaries of the Zoological Society will be models to show how many living beauties may be natu- ralized in this country. But, if I might be allowed to make 108 Observations on the the observation, I think the design which is shown for the aviary in the Regent's Park, although exceedingly elegant in appearance, yet will not succeed for keeping the birds. It is too exposed and open to the north and east to afford any mo-' derate degree of shelter to the birds during winter, and 1 fear many will thus perish. My friend, Mr. MaHphant, architect, in Blenheim-street, has been so kind as to embody my ideas in a design for an aviary, which would, I think, combine all the advantages of shelter and ornament. The front and roof are proposed to be of glass. The centre-part and two wings may be either covered in with glass or patent zinc. A walk may be made within the glass, and outside the wire, as it is proposed to leave a space of five feet between the glass in front and the wire, which would afford room for a paved walk, and a bed for exotic plants ; thus combining the beauties of the aviary and the conservatory. It would be advisable to have the wire at the roof within two or three inches of the glass. The same plan would do exceedingly well for a common aviary, in which case wire would be substituted for the glass ; and the rooms at each end would be useful to contain delicate birds during the winter months. A. Observations on the Force of our Ships of War, During the last few years, naval matters have been gradually coming before the public eye. Open and free discussion has, at last, made its appearance, and, as usual, has produced vast benefit in dispelling the mystery and darkness in which the construction, equipment, and economy of our naval force were formerly concealed. It is a singular fact, that a Frenchman* should have been the first to have deemed our naval establishment worthy of being described and descanted on ; but it is no less true, that we owe to a foreigner almost every information we pos- sess on the subject, as well as the attention he has excited by • Baron Charles Dupin— Force Navale de la Grande Bretagne. Force of our Ships of War, 109 his writings. That attention has been wonderfully increased ; and we now see this once neglected but most important national topic introduced in almost every scientific or literary pub- lication of eminence of the day ; and even periodical works expressly devoted to its consideration, have been published. It is true, indeed, that much erroneous argument, and, conse- quently, many false conclusions have proceeded from those who are unacquainted with naval philosophy ; but even these have been of service, for the detection and exposure of error is as important as the developement of truth. The accession of His Royal Highness the Duke of Clarence to the office of Lord High Admiral has given a fresh impulse to the desire of improvement ; and it is said to be in contem- plation to make some very important innovations in the arma- ment of our floating citadels ; it is, therefore, solely with a wish to aid the intentions of His Royal Highness, that we intend briefly to examine the principles to which such alterations should be referred, and to point out how far we are justified in proposing an adoption of them. The first element to be considered, in a ship of war, is, necessarily, its force ; and this consists in its artillery; but there are two ways in which this force can be modified, viz. — 1st. By the quantity of guns mounted. 2dly. By the quality or calibre of the ordnance. If we merely estimated the force of a ship of war by the number of its guns, we might be led into very great error. The famous Harry Grace de Dieu, built in 1515, was mounted with 122 pieces of ordnance *, a number exceeding even that with which our present first rates are established, but not more than thirteen of these were of the calibre of nine pounds, and upwards. The calibre of a piece of artillery gives us a definite idea of its individual power ; but this term alone does not furnish us with a correct notion of a vessel's force beyond that of carrying '' heavy or light metal." It becomes necessary, therefore, that both the number and calibre of guns must be expressed, to give us a precise description of the fighting power of a ship. * Charnock's Hist, of Marine Arch. vol. ii. p. 44. 110 Observations on the . In the earlier periods of the application of ordnance to naval warfare, it was usual to carry, not only various calibres on board the same ship, but even to have two or three different natures on the same deck. Much inconvenience and confusion must have unavoidably arisen on this account; but we find that it was not until the latter part of the reign of Charles I. that any attempts were made to remedy the serious evils inhe- rent in such a disregard of system. The first regular establish- ment of guns for the various classes of ships of the royal navy is, we believe, that given by Derrick, in his Memoirs, and was made in the year 1677. We find in it an uniformity of calibre established for each respective deck ; for instance, the lower deck of a three-decked ship of 100 guns was armed entirely with 42 pounders, or (as they were then called) cannon of 7 * ; the middle deck with 18-pounders, or culverins ; and the upper deck with 6-pounders, or sakers. As may be naturally supposed, repeated attempts have been made to increase the force of our ships of war ; not only by increasing the number, but also by increasing the calibre, of their ordnance ; but the former alternative has, from the diffi- culties and expense attending it, (by requiring much larger ships,) been comparatively little resorted to ; indeed, we find that our present largest first rates carry only twenty guns more than the first rates in 1677 ; and our largest two-decked ships of the line mount only fourteen more than the two-deckers of the same period. Hence it has been principally in the general increase of calibre of naval ordnance that the present superior force of our floating batteries consists. In treating of cannon with relation to the qualities and capa- bilities required in them, as forming the armament of a ship, it will appear, on a due consideration, that there are two prin- cipal objects which should be attended to in the construc- tion of a piece of sea-service ordnance, viz., facility of its service in time of action, and the influence which the guns possess over the sailing qualities of the ship : both these desi- derata are dependent on the weight of the gun. This element not only governs the celerity of its service, but also has a great * That is, cannon of seven inches, or whose bore was seven inches in diameter. Force of our Ships of War, 111 influence on the displacement and stability of the vessel ; it is chiefly on the latter account that in ships of two or more decks, it becomes necessary to diminish successively the weights ; and, according to the common constitution of artillery, the calibres in the upper tiers. Since, therefore, it appears that the guns of the greatest weight should be placed on the lowest battery, it will be im- portant to see how far experience has determined this maxi- mum *, which^ of course, must, above all other considerations, depend on the power and ease of management in time of action. Manual exertion is confined within comparatively narrow limits ; but it is possible to construct a vessel that should carry much heavier ordnance than the heaviest now used. A mass of about 80 cwt. seems, from experience, to be the maximum of weight that can be allowed without losing the requisite cele- rity in the service of the guns. This we ascertain, not from our own practice, but from that of a foreign nation. The weight of a French 36-pounder and carriage is 83 cwt. f ; that of our highest calibre of sea service long-gun and its carriage is only 64 cwt. J : we see, therefore, that the French retain, as manageable, a weight exceeding ours by 18| cwt., or nearly one ton. Admitting, however, that our 32-pounder is equivalent in force to the French 36-pounder, and is otherwise as good a gun, it would have the advantage in a long action, since it could be served with much less fatigue and with fewer hands. This is certainly an important consideration ; but the same re- commendation, in a considerable degree, will be found to have been attached to a higher calibre of English ordnance now discarded from the naval service, excepting in the form of car- * This quantity is much greater in the sea service, than in the land service, on account of the loco-motion which naval ordnance possesses in common with the ship on board which it is mounted. Garrison ord- nance, however, from being stationary, is as heavy as that of the sea service ; and, indeed, is generally, in the British service, supplied from it. t The weight of the French 36-pounder used on the lower decks of their ships of the line, is nearly 71 i cwt., and the carriage weighs 11^ cwt., making together 83 cwt. t The English 32-pounder gun of 9J feet long, weighs 56 cwt., and its carriage 8^ cwt., m^ing together 644 cwt 112 Observations on the ronades. The 42-pounder gun, until the year 1793, formed the armament of the lower decks of all our first rates, and weighed 63 or 65 cwt. ; so that even this heaviest of English naval ordnance, which was dispensed with on account of its unmanageable weight, was at least one-third of a ton lighter than the truly powerful gun which still forms the principal arm of the line-of-battle ships of the French navy, and the weight of which has very recently been adopted by an author* of great merit, as that which is sufficiently manageable. We now proceed to make a few remarks on the calibres of ordnance used on board ship. The celebrated Robins, in a tract, first printed in 1747, entitled *^ A Proposal for increasing the Strength of the British Navy," fully points out the great augmentation of force to be derived from using higher calibres ; and Muller, in his Treatise of Artillery, in 1768, makes a simi- lar proposition. The fact is, that the larger calibres possess the great advantage of making greater breaches in an enemy's hull ; their superiority of mass produces a greater momentum with a given velocity, and their ranges are greater even with a less proportional weight of powder. The calibres of our guns should never be much less than those used on board the ships of other nations ; they may be as much greater as possible. Experience has shown how much our 18-pounder gun, the common armament of our most numerous class of frigates, compromised their safety, when op- posed to the 24-pounder of the American frigates, in the last war. The Portuguese still use their 48-pounder, equivalent to 45.79 lbs. English calibre, for their heaviest ship gun, and the Dutch their 32-pounder, equivalent to the calibre of 34.54 lbs. avoirdupois : the Russians, Swedes, and Spaniards, use their several 36-pounders, respectively, equal to the calibres of 31. 95, 33.73, and 34.42 lbs. avoirdupois. All these guns, except the Russian, are, therefore, superior to our heaviest calibre, the 32-pounder. But this last gun, which forms the arm of the lower decks of all our ships of the line, stands in a greater ratio of inferiority with the French 36-pounder, than even the ♦ M. Paixhans, Nouvelle Force Maritime, 1820. Force of our Ships of tVar, llS 18-pounder to the 24-pounder. The French 36.poiin(l ball is equivalent to the calibre of 38.86 lbs. avoirdupois, being nearly seven pounds heavier than our 32-pound shot. This superi- ority of the French naval ordnance has been often felt by naval men. Captain Brenton, in his Naval History, repeatedly mentions the 36-pounder as giving the French navy a decided advantage. This advantage they have always retained in their two-decked ships of the line ; but until 1793 our three-deckers, with their 42-pounders on the lower deck, possessed the supe- riority over the force of the same class of ships of the French marine. The 42-pounder gun rejected in 1793, though 7 or 8 cwt. heavier than the present 32-pounder, was lighter than the French 36-pounder, by 6 or 8 cwt. ; and, before it was thrown out of the service, some means should have been devised to have rendered its management, at least, equally easy as the French 36-pounder gun, which, as we have already said, has been unequivocally declared to be sufficiently convenient in its service. It may here be observed, that the Americans have adopted the calibre of 42 pounds for the guns of the lower decks of their three-decked ships ; and we should not omit to mention that, with the present service charge, the point blank range of a 42-pounder is fifty yards more than that of the 32-pounder ; and that at the small elevation of 1° the range of the former exceeds that of the latter by nearly 300 yards *. As it has been most decidedly proved by Mutton's valuable experiments on military projectiles, that the weight of a gun of given length has no influence on the velocity of the ball, we have only to refer this element of a piece of naval ordnance, besides the power of management, to the attainment of a steady recoil ; to the necessary length; and, lastly, to the required thickness of metal. We suspect that much needless weight had been added to the 42-pounder, for we find that in 1768, that nature of ord- nance weighed only 55j cwt. f Mr. Muller, whose work on artil- lery gives us this information, does not mention any objection ♦ Vide Naval Gunnery, by Sir H. Douglas. •I- Mailer's Treatise of Artillery. JULY— SBPT. 18*28. I 114 Observations on the to this weight, but that he thought it too great, and proposed a 42-pounder of 52J cvvt. We may, therefore, safely assume that it was a serviceable gun in every respect ; and as it was ten feet long, a diminution of six inches in length might either have reduced this weight, or, retaining the same weight, have obtained a greater thickness of metal at the breech. It appears, from the best authorities, that the weight of the 42-pounder gun has varied from 55J cwt. to 65 cwt., and the length from 9 to 10 feet. The greatest length now allowed for sea-service guns, is 9J feet. The brass 9^ feet 42-pounders of the famous Royal George, which was, we believe, the last ship in our service armed with brass guns, weighed rather more than 61 J cwt. each. From these facts we may infer, that suf- ficient steadiness of recoil can be obtained when the ratio of the weight of the gun to the shot is greater than that of 147 to 1. There cannot, therefore, be a doubt but that the 42-pounder might be again introduced into the catalogue of sea-service ordnance, with a weight of 61 cwt., or half a ton lighter than the present French 36-pounder gun : now, if we dispensed with the useless mass of metal about the muzzle, which only detracts from the elevation, depression and training of the gun, and renders its service doubly delicate*, and disposed it about the breech, so as to give a more conical form to the piece, there would result the advantages of a greater projection of muzzle beyond the port, and a much stronger gun. This conical form has been fully proved to be the proper one for sea-service, as exemplified in the Congreve 24-pounder, which forms the pre- sent arm of the upper decks of our fir^t rates. * All gunnery operations at sea ought to be reduced, if possible, to an unity of purpose, and the mind of the gunner should not be distracted by two intentions, viz., hitting his mark, and preventing the swell of the muzzle from breaking away the side of the port in the recoil, and doing other mischief, on account of this contact taking place. The muzzle swell should be got rid of, and the chace carried right through, excepting at the quarters, where the swell might be left, so as to afford a sufficient hold for the muzzle lashing, when the gun is housed. Such a piece of ord- nance could not wood or strike the side of the port in its recoil. The present ordnance could, at a small expense, be altered, to effect such a desirable purpose. It is true that the quarter sights would thus be aban- doned, but at sea they have very rarely been of any service, and, with the present sights, are rendered wholly unnecessary in the operation of point- ing guns on board ship. Force of our Ships of War, 115 Admitting, howeverj that the size of the shot of 42 pounds weight renders it too difficult for a man to manage with ease, when quick firing is required, and this appears to us to be the only feasible objection to it, we cannot imagine that the same objection can possibly be urged against the ball of 38 or 36 pounds weight. The diameter of the 42 pound ball i|S 6.684 inches 3 the diameter of the 38 pound shot 6.465, and that of the 36 pound bullet 6.35 inches. We understand that it is contemplated to put 32-pounder guns of the increased weight of 63 cwt., in imitation of the Americans, on the lower decks of our ships of war of two and three decks, removing the present 32-pounders of 56 cwt. to the deck above ; and mounting, in three-decked ships, guns of the same calibre on the upper deck, but of only 49j cwt. Now, if this measure be adopted, for the purpose of obtaining an unity of calibre y we say that it will be done with much more weight than is necessary, and that, by again introducing a gun of 63 cwt. into the naval service, an opportunity offers of raising our maximum calibre to very nearly that of the French, by intro- ducing the calibre of 38 pounds, with a gun 9J feet long. Although in establishing an unity of calibre with the maxi- mum calibre as its base, we certainly increase the weight of metal thrown at a broadside ; yet, before we decidedly pro- nounce it to be an increase of power, we must first inquire at what distance this modified force is efiective. The fact is, that- such a step requires some consideration, and should be referred to the principle, that none of the superior calibres of ordnance should be inferior, in point of range, to those it is intended to supersede. For instance, the guns of the middle deck of a three-decked ship should possess, with the proposed higher calibre, a range not inferior to the 24-pounders they are sub- stituted for. We shall now proceed to examine how far this is practicable with a calibre of 38 pounds. It has been already mentioned that the weight of a piece of ordnance, considered merely as a projectile instrument, is only referable to its influence on the recoil, and the strength re- quired throughout the length of the bore to resist the action of the charge with perfect safety. Now, if we refer the weight of a 38 pound ball to 63 cwt., we should have a ratio of 1 to I 2 llB Observations on the 186.31, which all experience has proved to produce a very steady recoil: in fact, the ratio of the ball of 32 pounds to the weight of the present gun of that nature, is less by only six times the weight of the shot. But a question now arises of great importance. Are we to lay aside all the ordnance of the calibre of 32 pounds, merely to introduce that of 38 pounds, and thus entail a great loss on the country ? We answer, no ! The present 32-pounder gun of 9j feet long, and 56 cwt, if rebored or reemed out to the calibre of 38 pounds, would still weigh 55.12 cwt., or 162.55 times its new shot, which is very nearly the ratio between the weight of the brass 42-pounder of the Royal George, and its shot. The 32-pounder gun of 8J feet and 49i cwt., might similarly be adapted to the calibre of 38 pounds, with a loss of only 81 lbs. of metal, which would reduce its weight to 142.28 times that of the ball, or nearly the ratio subsisting between the old iron 42-pounder of 55 cwt., and its shot, and which used to be fired with charges of half, two-thirds, or even three- fourths the weight of the shot, instead of the present lower charge of one-third the weight of the shot. This modification would cause but a very slight decrease of thickness of metal in these two guns ; for the diameter of a 38 pound ball is 6.465 inches, and if we add to this the windage now adopted for all calibres of heavy ordnance above 12-pounders, viz., .15 of an inch, we have 6.615 for the diameter of the bore of a 38-pounder gun. Now the diameter of a 32-pounder shot is 6.105 inches, and with the common windage to which these guns are con- structed, we shall have 6.41 inches for the calibre of the present 32-pounder gun : hence this gun can be reemed out for a •38-pounder, with an increase of calibre of .205 of an inch, or a decrease in thickness of metal of .102 of an inch ; a quan- tity too trivial to excite the slightest apprehension of bursting*. * In reeming out the 32-poimder for our purpose, the part of the bore about the charge might be left as it is, and thus preserve the original thickness of metal. The enlarged part of the bore being carried into it in the surface of a hollow conical frustum, so that the shot being forced into it would always have its centre in the axis of the bore, — an advantage 'too obvious to be insisted upon. This idea we owe to M. Gomer, a French artillery officer of distinction, about the middle of the last century ; and M. Paixhans has availed himself of it in a similar manner, as we jnay see in his " Nouvelle Force Maritime." - Force of our Ships of War, 117 From Hutton*s experiments, we may conclude that, in dif- ferent calibres of guns having the same length and windage, the ranges at the same elevation are nearly as the fourth roots of the charges directly, and inversely as the fourth roots of the weight of the shot; hence the range of a 38-pounder of 9^ feet long, with 10 lbs. of powder, is to the range of the 24-pounder of the same length, fired with 8 lbs., as 3.93 to 4.17, a pretty near approximation to a ratio of equality ; but if we consider that the proposed 38-pounder has nearly one half less windage than that hitherto allowed to the 24-poander, we may safely reckon on the usual full range of a 24-pounder being given to the 38 pound balls projected from the middle and upper tiers, with the charge proposed. Indeed, from some recent experiments * made on the windage of guns, such a result cannot be doubted. If, therefore, it should, upon actual trial, be found incon- venient to employ the full service charge of one-third the weight of the shot for these converted pieces, and thereby have an unitij of range, as well as calibre, to our proposed arma- ment J, we may still secure to ourselves, with a reduced charge, all the advantages that arise from projecting a shot of 38 pounds to the same distance as we do at present those of 241bs. and 181bs. from the same decks. The same remarks apply in degree to the use of double-shotted discharges : and we may, in adverting to the use of two shot, remark, that the great un- certainty of hitting the object with double-shotted guns, ex- cepting when very close, should always prevent a ship from throwing away its fire in double shots, at long ranges, with the full service charge. This is a fact, we believe, so fully esta- blished by careful experiment, and so generally admitted by those most conversant in practical gunnery, that we need not insist on it any further than by saying that it is better to * Vide Sir H. Douglas's Naval Gunnery ; wherein it appears that the range of a 12-pounder, whose windage was .1 of an inch, instead of .22 of an inch, (the common windage,) was rather greater with l-6th less powder than the usual charge. t This would be rigorously correct^for two of our guns, as they are of the same length, and very nearly so for the three, as the gun of 49i cwt. is only twelve inches shorter ; and the ranges are nearly as the Jffth ropts Of the lengths, with the same charges and calibres. 118 Observations on the fire only one shot with certainty, than two with the chances of throwing away both. We contend, therefore, that an experiment with the gun proposed of the cahbre of 38, and the present 32-pounders bored out to the same calibre, as also the 32-pounder carronade similarly converted, should be made to ascertain whether it be not possible to introduce the calibre of 38 pounds into our naval service as the sole arm for all ships of the line and heavy frigates ; and that such an opportunity as the present should not be allowed to escape us without making the attempt. M. Paixhans, in his ** Nouvelle Force Maritime," proposes the calibre of 36 pounds^ as the only one for naval service ; but, in adopting his suggestion, we are necessitated, in the smaller vessels of war, to make a sacrifice of range by employing lighter guns than we propose : thus, in the 64 gun frigate he would be obliged to employ the 36-pounder of the same weight as the 24.-pounder it would supersede, but of less power of range, because projecting a heavier shot with only the same charge as the latter gun. This deficiency would become still more ap- parent in the next class of frigates, where he proposes to em- ploy a 36-pounder of the same weight as the 18-pounder, which is the present arm ; and it becomes a matter of grave consideration whether, in such cases, it would be prudent to give up power of range for the increase of calibre, as derived from his system. In advancing our proposition, we do not pretend to original- Kty, as it is only a modification of that of M. Paixhans ; but we possess a singular advantage over him, in point of economy ^ inasmuch as with only one new nature of ordnance we can ob- tain all the advantages to be derived from an unity of calibre, with a corresponding increase of force over our present sea- service ordnance, by taking the maximum calibre at a higher point ; whereas this author is obliged to go to the great ex- pense of introducing two new descriptions of ordnance, besides throwing aside those of 24 and 18 already in use. It may also * This author adopts .the present French 36-pounder, and two others; one of which is 142 times the weight of the shot, and the other 1 1 6 times. Force of our Ship^ of War, ll9 be crt)"S6rved, that the 38-pounder we propose to obtain from the 9J feet and 8 j feet 32-pounder, are much superior in rela- tive weight to the two lighter and shorter 36-pounders of M Paixhans, and, therefore, capable of bearing larger charges, and producing greaiter ranges than his guns. The additional weight accruing from this armament, in a ship of 120 guns, would be nearly 91 tons *, which would cause her to sink about 3j inches more than with the common ordnance equipment. Thus we have proposed a scale upon which our naval ord- nance may obtain the maximum of simplicity, together with an increase offeree, which, if we adopt the calibre of 38 pounds, will amount, in a ship of 120 guns, to nearly half as much metal again being projected at each broadside than is thrown by the usual armament f . M. Paixhans has proposed, with great plausibility, the intro- duction of shells into naval artillery, and his system has been par- tially experimented on with much apparent success J ; but although his proposition opens the door for a fresh modification of sea-service ordnance, we imagine that there are certain ob- stacles arising from the peculiar nature of naval warfare, which will render the adoption of it, to its full extent, very difficult. The great feature in it, besides that of explosion, is the pro- perty of giving hollow shot much larger calibres than our largest solid shot, with less weight than the latter, possess. For instance, the hollow shot of the calibre of 80 pounds, or 8 inches French in diameter, weighs, when filled, only 55 pounds French, or about 60 lbs. avoirdupois ; the hollow shot of the calibre of 150 pounds, or 10 inches French in dia- meter, weighs only 110 pounds French, when filled, or nearly, or 119 lbs. avoirdupois. It must, however, be recollected, that in augmenting the calibre to, perhaps, 10 inches, in the manner proposed by M. Paixhans, there arises a disadvantage in the loss of time ; for * This weight is estimated at the war proportion of ammunition. t A broadside of sixty 38-pounders will project 2280 pounds of metal ; a broadside consisting of sixteen .32's, thirty-four 24 's, six 32 pounder carronades, and four 1 2-pounders, only amounts to 1568 pounds of metal. I See No. 2 of the Naval and Military Magazine, for June, 1827. 120 Observations on the Force of our Ships of War, the size of the projectile and its weight, become again so con- siderable *, that it will require two men to carry it ; and if the sea be agitated, this inconvenience will be still more feltt. It is on this account, chiefly, that it requires to be decided by an actual experiment at sea, whether there would result any real advantage from having an entire battery, say of 68-pounders even, over one of 38-pounders. The former, we apprehend, could only fire, from their relative lightness J, single shot ; whilst the latter would pour in double shot, and more than twice the weight of metal at each discharge, besides making two large breaches, instead of one. We do not say, however, that the 68-pounder may not be advantageously employed when partially adopted, as at present, on the lower decks of our ships of the line ; but the practice brings along with it the evil of having two calibres on the same deck. We should prefer them in midships, and weighing as much as 55 or 60 cwt. Three or four, or perhaps half a dozen, of a side, although slow in their service, would prove, when discharged at a critical moment, for which they might be reserved, a tremendous auxi- liary to ordnance already advanced to the greatest calibre, with- out sacrificing the necessary celerity in working, and powers of range ; and if a separate magazine in midships were con- structed for the ammunition of these pieces, confusion might be avoided in the hurry of action. We shall abstain from making any further remarks on the subject of hollow projectiles for sea-service, because the idea has not yet been sufficiently put to the test of experiment, and certainly not at all to that of actual service. The force of a ship of war is, as we have already said, the first element to be considered in its theoretical construction ; and we might here proceed to explain its influence on the pro- portions and sailing qualities ; but this will more properly be a subject for future consideration. * The weight of an English ten-inch hollow shot, when filled, would be 95 lbs. ; and when empty, about 85 i lbs. t M. Paixhans himself seems to be fully aware of the magnitude of these difficulties. % The new 68-pounder gun introduced by General Millar, weighs only 82 times its shot. ' ^ 121 An Account of a New (jfenus of Plants called Diplogenea. By John Lindley, Esq., F.R.S., Professor of Botany in the University of London. The genus which is the subject of the following observations forms part of a small collection of plants gathered in Mada- gascar, for the Horticultural Society of London, by the late Mr. John Forbes. By permission of the Society it has been allowed to be described and made public in this Journal. The specimens consist of a few shrivelled branches with flower-buds and expanded flowers, but without fruit. From their appearance, it may be presumed that the plant to which they belonged was parasitical. The branches are brown, taper, fleshy, glabrous, very zigzag in direction, when young compressed, with a few dichotomous ramifi- cations ; the joints seem to have been rather tumid. The leaves are opposite, fleshy, spreading, glabrous, entire, oblong, retuse, tapering into a short petiole, triply ribbed, but other- wise destitute of all appearance of veins ; their parenchyma, consist of large irregularly hexagonal cells, many of which are evidently filled with an oily fluid. The flowers are small, and appear in very short, axillary, fascicled racemes ; their colour has probably been white. The calyx is fleshy and superior, with the limb falling off" like a lid, and leaving a sue- culent dilated border behind ; it adheres firmly to the ovarium on all sides, and when the lid has fallen, which happens at an early stage, resembles a truncated calyx ; the coat of the tube distinctly abounds with receptacles of oil. The petals are four, lanceolate, acuminate, fleshy, involute at the apex, and hav- ing a twisted aestivation ; they are inserted on the outside of a flat or concave fleshy disk, which occupies the summit of the ovarium. The stamens are eight, inserted in a single row on the outside of this same disk ; their filaments are ligulate ; their anthers in aestivation inflexed, ovate, acute, with two parallel cells communicating by a single pore at the apex, and having at their base two subulate, falcate spurs, or appendages; when the flower is expanded, the anthers acquire an erect po- sition, and their lobes, which were before turned outwards, have an inward direction, The ovarium is inseparably connected 122 Mr. Lindley on Diplogenea, with the calyx np to the point where it is covered by a flat or slightly concave fleshy disk ; it apparently contains four cells, with numerous minute ovula attached to placentae in the axis. The style is falcate, and thickened upwards ; the stigma is a simple point. Of the fruit nothing is known. It will have been already remarked that in many particulars this genus exhibits the common structure of Melastomaceae, and that in fact it is very nearly related to, if not identical with, Conostegia. But there is a remarkable peculiarity in Diplo- genea, which renders it impossible to associate it with any known genus of Melastomacere. This consists in the presence of re- ceptacles of oil lying under the cuticle among the parenchyma, a character which it has been hitherto supposed that no Me- lastomaceous genus possesses, and which has been always em- ployed as one of the chief distinctions of Myrtaceae. I do not, however, think that the degree in which these receptacles exist in the genus under consideration will much invalidate the character of Myrtaceae, because they are in too rudimentary a state to be actually identified with the transparent cells of that order ; all that I wish to show is, that an evident tendency to produce oily secretions exists in Melastomacese, a tribe in which no such tendency has been before noticed. In the absence of fruit, the characters of this genus can be only imperfectly traced ; but the following will be sufficient to distinguish it from all that have been previously described. DIPLOGENEA. Nat. ord. Melastomacecu ; C onostegiae proxima. Calyx superus, limbo calyptriformi conico deciduo. Petala 4, lanceo- lata, in margine disci carnosi ovarium tegentis inserta. Stamina 8, circa discum inserta ; antheris ovatis, basi bicalcaratis, poro apicis dehiscen- tibus. Ovarium calyci oranino accretum, 4-lociilare, polyspermum, disco magno carnoso coronatum. Stylus falcatus, clavatus. Stigma simplex. Frutex parasiticus ? glaberrimus (Madagascariensis). Rami carnosi, dichotomi,junioribus compressis, Visciferl habitu. Folia oblonga,retusa, tarnosa, triplicostata, avenia, receptaculis olei intra parenchyma latefi" tibus. Flores albi 9 parvi, in racemis brevibus, axillaribus dispositi, Calycis tubus receptaculis olei repletus. 1. D. viscoides. Ad portum Sae. Marise, Insulse Madagascarise, legit Johannes Forbes. iv. s, sp, herb. Soc. Hort, LondO 123 A Dissertation on the JVature and Properties of the Malvern Water, and an Enquiry into the Causes and Treatment of Scrofulous Diseases and Consumption, together with some remarks upon the Influence of the Terrestrial Radiation of Caloric upon local salubrity. By W. Addison, Surgeon, Malvern has for a long period been justly celebrated for its pure and invigorating air, the excellence of its water, and the romantic beauty of its scenery. Dr. Wall^ who wrote some years since a small work upon the efficacy of the Malvern Waters in many diseases, speaks highly of the benefits expe- rienced from a residence at Malvern in scrofulous, nephritic, and many other complaints. Mr. Addison's work is scientific and ingenious ; he attributes the many extraordinary recoveries which have occurred at Malvern, partly to the salubrity of the air, and partly to the purity of the water, which, from the analysis he has given of it, seems to contain much less saline or earthy matter than any we are acquainted with ; and we think he has laboured, with considerable success, to prove that the continued use of a pure water may be a powerful means of removing and preventing many chronic disorders ; his views of the causes of scrofulous diseases, — the circumstances which determine their seat or situation, — and the measures calculated to counteract a tendency to them are in our opinion, extremely creditable to his professional ability. The work contains many clear state- ments, with some accurate reasoning, which we can with confi- dence recommend to our readers. The last section treats upon a subject altogether new in medical science, though the facts to which Mr. Addison refers have been long known to the cul- tivators of chemistry. That the radiation of caloric from the earth will have a very great influence in the production of va- rious diseases we are certainly much inclined to admit, and we feel induced also to believe, with our author, that the activity of malaria may very much depend upon this process. The re- marks and observations which Mr. Addison has made upon dis- eases as they appear in tropical climates, certainly furnish a powerful statement in favour of the views he has taken. We earnestly recommend this subject to the profession of which Mr. Addison is a member; the conclusions he has djawn are, that all those places where the radiation of caloric goes on with rapidity, will oe found subject to great vicissitudes of temperature, to fogs, heavy dews, and other noxious precipitations from the air, tvhereby they are rendered cold, damp, and oftentimes extremely unhealthy, while, cseteris paribus, those situations where the 124 Mr. Meikle on the terrestrial radiation is diminished willhe projwrtionally warmer ^ drier, of a more equable temperature, and more healthy. We have been given to understand that this enquiry will be resumed by our author in a paper, which will shortly appear in one of the scientific periodicals. On Mr. Ivory's Investigations of the Velocity of Sound. By Henry Meikle. In the article on sound inserted in the Edin. Phil. Jour, for October, 1827, I had acquiesced in the theory of the late cele- brated Marquis Laplace, so far as it appeared to go, and only suggested some small additions to it. But since writing that article, I have examined more closely the investigation of that eminent mathematician, given in the Conn, des Tems pour I'an 1825, and Mecanique Cdeste, torn. v. page 119, and am now convinced that it is in itself objectionable in several re- spects, independently of any thing which I formerly hinted : so that my proposed amendments on this theory are as nothing compared with the thorough reform it would require ; the result being neither deduced from correct principles, nor by means of an accurately managed calculus. The like objec- tions attach to Mr. Ivory's view of it, given in the Phil, Mag. for July, 1825, p. 11. To this I shall principally direct my remarks at present, because it is better known in this country, and is given in a more detached form than that of M. Laplace, which, though essentially the same, and, in fact, the groundwork of the other, is curiously interwoven with some untenable speculations regarding heat*. Considerable obscurity pervades Mr. Ivory's investigation, especially in laying down the first principles, which are both inconsistent and defective. Several of the most important circumstances are overlooked altogether ; but, as will be seen from extracts which soon follow, the leading idea by which the * In the Conn, des Terns for 1826, M. Poisson has treated the subject in a more general way, with the view of embracing cases where the me- dium is not uniform. The length of his Memoir would render it tedious fully to discuss its merits; but, so far as regards the ordinary case of sound traversing the horizon, it is not materially different from that about tp be examined. Velocity of Sounds 12Sf process is meant to be regulated is briefly this : — A minute cylinder of air, whose length varies without either changing its mass or diameter, is supposed to be acted on by an accelerating force, till it move over a small space z, and then abandoned to move uniformly with the velocity so acquired along a straight line a?*. This latter motion is intended to represent that of sound, and its velocity is assumed, without either proof or pro- bability, to be always the same, and, consequently, without either decrease or end, in air of the like density and pressure. It is further supposed, that the cylinder always moves over a space equal to its own length during the constant fluxion of time dr, and that it does so whether in passing over z or x. Now without enlarging on the faint enough resemblance between this leading idea and the propagation of sound, it may be observed, before entering on further particulars, that either the space z, no matter how small, must be always of the same magnitude, and therefore the intensity or loudness of sound always the same in air of the like condition, which is contrary to universal observation ; or else, the accelerating force must be everywhere inversely proportional to the space z. Without some condition of this nature, the final velocity with which the cylinder is projected, or the velocity of sound, cannot, as our * This notion seems, in the first instance, to be borrowed from that usually given in elementary books on mechanics ; where it is, in effect, shown that if a series of equal and perfectly elastic bodies, such as cy- linders, be placed contiguous, having their axes in a straight line ; and if an impulse be given to either extreme cylinder, it will communicate an equal impulse to the next, and this to the next, &c., till the whole series be run over. But to this is joined the assumption, that the velocity with which the impulse is propagated along the series is the same as the velo- city of the first cylinder would have been, if alone, or projected by itself, — a coincidence for which I know no reason, nor can I believe it to be pos- sible. But admitting it were true, since, as we shall presently see, the velocity of the projected cylinder must be proportional to the projecting force, how does this consist with the rate of propagation being likewise assumed to be ever the same in the same state of the medium ? Some, perhaps, could tell us that the series of cylinders propagate the impulse, as if they were so many isochronous pendulums ; but where is the proof? and I may again ask, how such a determinate velocity of sound can be aptly represented by the precarious velocity with which the cylinder may be projected ? For, at all events, the calculus is conducted with reference to a projected cylinder. But supposing the investigation were to relate only to " the vibrations of a line of air," it would not be less objectionable ; as, for instance, what could we make of the curious absurdity, to be shortly noticed, of the small cylinders of air being compressed till ?w/?- nitely dense, at the tiurn of each vibration ? 126 Mr. Meikle on the author assumes, be always the same in the same medium. For, to attain the same final velocity, the circumstances must be similar to those of a weight descending an inclined plane of a given height ; where, abstracting from friction or other resis- tance, the accelerating force is inversely as the plane's length. But, in the case before us, the law of the force accelerating the cyhnder must be of a very opposite description 5 for, as we shall afterwards see, in order that the velocity of sound, as de- duced by this sort of investigation, may be independent of the intensity, or of the degree of condensation, the elasticity of the air would require to be either independent of, or to vary in- versely as, the density, which are alike absurd ; but here the elasticity is supposed to vary directly as the | power of the density. That the above are not the only serious charges which may be brought against Mr. Ivory's investigation, will appear from the following extracts ; to which I shall subjoin some remarks, for the purpose of pointing out a few more of the tacit assump- tions and undefined steps, which are not unfrequent, and for setting their merits and mutual relations, which are sometimes curious, in a proper point of view : — '• Conceive a slender horizontal tube of an indefinite length, containing air in a state of equilibrium ; and let x, reckoned from a fixed point in the axis of the tube, be the distance of a small cylinder of air within the tube, the thickness (length) of which is equal to dx. Suppose now that the cylinder is pushed forward by some force to the distance x+z from the fixed point, and that it occupies the length dx+dz in the axis*. It is to be * It is not, however, this movement of the cylinder over the space z that is considered in the sequel of the investigation ; but its retracing of it occasioned by the natural tendency of the air to regain its equilibrium, and which accelerates the cylinder back over the space z towards the assumed point from which the distance x + z was reckoned. A concus- sion or tremor is thus produced in the air, and propagated from atom to atom along the line x ; and it is conceived that this tremor or sound moves uniformly along x with the velocity, whatever that be, which the cylinder has acquired during its acceleration over the line z. This supposed uniform velocity of the cylinder projected along x is further conceived to be the same with the velocity it happens to have, whenever its density equals the mean actual density of the medium. If so, how does this consist with the well known fact, that the series of aerial vibrations conducting sound through the atmosphere always get feebler and feebler as they become more distant Velocity of Sound, 127 observed that dx is invariably of the same magnitude, whatever be the position of the small cylinder of air, and that dz alone varies in different places of the tube, and at different times. It follows, therefore, that x is independent on the time t, and z is a function of x and t. It is to be observed too, that the air is supposed to undergo very small condensations and rarefac- tions in proportion to its original bulk in the state of equili- brium ; that is, dz must be considered as very small when compared to dx*. Let §' denote the density of the air in equU from the sonorous body, and, consequently, the velocities of the atoms slower and slower at those similar points of their vibrations in which the densities of the cylinders become equal to the mean density of the me- dium ? But ample reason may be given for the fundamental fact just stated, though Mr. Ivory has entirely overlooked both it and the reason. For admitting that the motion of the cylinder were, as he assumes, uni- form in a tube, yet in the free air, sound is sent off as from a radiant point, in every open direction not opposed to the wind. Nay, sound reaches many a place by a curvilinear rout, even without being reflected. It is therefore plain, that the area of each wave or spherical shell of air, to which the tremor is communicated in succession, will increase as fast, at least, as the square of its radius, or of its distance from the radiant point. In other words, the number of atoms or the mass to be successively set in motion will, supposing the medium uniform, increase as fast, at least as the square of its distance from the sonorous body. This is a very dif- ferent thing from saying off hand, that ** the cylinder in motion has always the same mass." Hence, as might easily be shown from known princi- ples, the motion of sound computed on projectile principles, instead of being uniform, ought to decrease as fast, at least, as the reciprocal of the distance from its source decreases. Sir Isaac Newton's view of the subject is incomparably more consistent than the one before us. He supposed all the vibrations in the same uni- form medium to be isochronous, or performed in equal times, however different their lengths, and, consequently, however different the velocities of the atoms at like points of their vibrations. Indeed, it is easy to see that there is no way in which the velocity of sound could be uniform, but by the vibrations, however different in length, being isochronous. New- ton, and his earlier followers, were well aware of this circumstance ; but vibrations of different lengths are quite at variance with, and cannot enter as an element into, the refined mode of viewing sound under the emblem of a projected cylinder, going on for ever, as the theory implies, without either decrease of velocity or of loudness. There is, however, no reason to think that every conceivable or possible law of elasticity in air would give isochronous vibrations ; nor am I aware that such has been proved, from legitimate theoretical principles, to hold of even one particular law, far less of that which belongs to the atmosphere. — H. M. * It would be difficult to reconcile almost any of these remarks either with each other, or with the very opposite principles acted on in the rest of this research. As, for instance, by strictly following up the leading principles of the investigation, it appears that dz, instead of being incom- parably smaller than dx^ must occasionally equal it \ and that the con- 128 Mr. Meikle on the librio, and § the variable density of the agitated cylinder ; then, the masses of the two cylinders being the same, their densities will be reciprocally as the volumes : therefore P — c?a? ^ ^ ^ dz p' dx+dz dx* the powers of the small fraction -- being rejected*. This equa- tion, it may be remarked, implies the continuityof the fluid f, since the cylinder in motion has always the same mass. Let P' denote the elastic force of the air in equilibrio, and P the like force of the agitated cylinder ; then, if we adopt the law of Boyle and Mariotte, we shall have -r-; = — ,- : and this equation would lead us to the result obtained by Newton J. But if, according to the observation of Laplace, we reason more densation, in place of being trifling, must be infinite. For, here the length of the cylinder is dx + dz, which binomial is likewise used as the fluxion oi z ; no matter how curious and undefined the notation, which Laplace, however, avoids. But when the cylinder reaches its utmost distance from the assumed point from which x -^ z\s reckoned, and is about to return toward that point, its velocity = ; and, therefore, the fluxion of the space = dx + dz = 0, and dx = — dz. Or, more properly, dx—dz = 0, and dx' = dz. For in this case, the fluxion of the space, or the length of the cylinder, is obviously the difference and not the sum of dic and dz^ because dx is constant. Hence, also, at the turn of the motion, the length of the cylinder is nothing, or its density is infinite ; a consequence, though absurd, yet inseparable from the tacit hypothesis which makes the cylin- der always move over a space equal to its own length, during.the constant fluxion of time dr. It is therefore certain, that the length of the cylin- der cannot consistently represent its velocity, or coincide with the fluxion of the space, as our author so conveniently assumes it to do, without offering the least reason for such illegitimate procedure. It is almost needless to add that the same assumption involves various other incon- sistencies, or to remark that the shattering of windows and crazy build- ings, the shaking of houses at considerable distances, the occasional deafening of persons, with many similar effects, could neither be pro- duced by small vibrations, nor slight condensations ; though infinite ones would be unnecessary. — H. M, * Since, as we have seen, dz sometimes equals dx, this fraction is occasionally considerable, or even equal to unit ; and, therefore, its powers cannot warrantably be rejected, either here, or again a little after in taking the fluxions. — H. M. ']' True, a continuity, but only in one direction through the tube | whereas, in the open air, the continuity is in all directions. — H. M, % We shall afterwards see this to be a mistake. — H. M. Velocity of Sound. 129 agreeably to what actually takes place in nature, and suppose that the elastic force of the agitated cylinder is exerted while it retains the whole of its absolute heat, the preceding formulge (D) * will furnish this equation, P' \ / J dxJ 3 ' dx Take the fluxions making x only variable |, and divide by the equal quantities § (dx-\-dz) and ^'dx ; then rfP ~ - i_ £1 _^ p idx + dz) 3 ' ^' ' dx^ * Now, P is the elastic force of the air in the tube at the dis- tance x+z from the assumed point in the axis, and F+dP is the like force of the air at the distance x+z+dx+dz ; wherefore dP is the effective force urging the intervening cylinder towards the assumed point: and as the mass moved is equal to § (dx+dz), ♦ The formulae referred to make the cube of the pressure vary as the fourth power of the density, which I consider to be the true law, though Mr. Ivory has since renounced it as incorrect, without giving any ad- missible reason ; but when he adopted this ratio, in the place from which he now quotes it, he did so for an erroneous reason, as I have hinted in the Edin. Phil. Jour, for January, ] 827. However, I do not think such a ratio applicable to the investigation of the velocity of sound, especially in the supposititious case of the tube before us. For though, in favourable circumstances, sound be propagated in every open direction from the. sonorous body, yet it does not appear that the air acts there exactly in its fluid character. Because sound which first passes through the tube, and then into the open air, does not proceed from the mouth of the tube, as from a sonorous body, in every direction, which it would do if the particles acted on each other with equal force in every direction. On the contrary, sound, as is well known, diverges but in a small degi-ee after quitting a long tube which merely conducts it ; and I rather doubt if it would di- verge at all, were it not for the friction or resistance which the vibrating particles suffer from their contact with air which is not in the direction of the tube. From this we should be led to infer, that the particles of air conveying sound through a narrow tube, es])ecially the ideal one free from friction, only vibrate in the direction of the axis. If so, the elasticity of air conducting sound through the tube should not be estimated accord- ing to the above law, but more nearly as in the inverse ratio of the squares of the variable longitudinal dimensions ; because, as I have shown on a former occasion, the particles of air repel each other with forces inversely as the squares of their distances. But we have already seen that the actual case of the atmosphere is totally different from that ofthetube.— H. M. t This is a curious injunction, more likely to embarrass and mislead the reader than any thing else ; for the equation in hand does not involve A' at all ; and, besides, Mr. Ivory, in the face of this strict precept, makes both P and dz variable. — H. M. JULY— SEPT. 1828. K 130 Mr. Meikle on the the quotient is the acceleration of each particle, otherwise ex- pressed by — -— ^ * ; wherefore ddz -_ j£ F ddz_ „ dT2 3 * y ' dx"- Were every thing correct about this equation and the mode by which Mr. Ivory has obtained it, the velocity would obvi- ously, as he in effect states it, be dx __ /Ip'" and since both dx and dr are constant, the velocity would be uniform, and always the same in air of the same density and pressure. But another notable error and inconsistency have here evaded notice, by the manoeuvre of twice rejecting the higher powers of dz^ seemingly for the purpose of rendering the calculus manageable, though, as we shall presently see, there was no call or necessity for it on that account. Whether M. Laplace or Mr. Ivory were aware of this circumstance, I could not pretend to say ; but one thing is certain, that further de- fects of the investigation become sufficiently apparent, when none of these powers have been discarded. For in this way we have Z. = ( dx \ F \ dx+dz ) dx+dz * Viz. one of the usual differential expressions for an accelerating force. The second fluxion of the space being ddz, and the undefined symbol dr denoting the constant fluxion of the time. It is from this step that it becomes more particularly obvious that the length of the cylinder is a measure of its velocity, being always equal to the minute space described during the constant moment of time dr. Not the shadow of a reason is either given or supposed necessary to assign why the length of the cylin- der should not rather have had some other relation to its velocity than that just mentioned, which we have already seen to be impossible. But the gratuitous assumptions in this investigation are so numerous and im- portant that they would have rendered it null and void as a mathematical production, although no inconsistency had presented itself. For were such assumptions to be tolerated in mathematics, there is no problem, however difficult, but they could solve with the utmost facility. A curious instance of their irresistible powers is noticed in the Phil. Mag. for Dec. 1822, where I have shown that the demonstration which Mr. Ivory sup- posed he had given of Euclid's 12th Axiom, in the number for March preceding, owes all its virtue to an assumption fully equivalent to tliQ axiom itself, which was the very point to be proved !— H, M. Velocity of Sound. 131 Take the fluxions, making dx and F constant, which gives ff£ = - 1 f ^^ ^T V ^ = - ± (l-Y X — P' 3 Vdr+rfz J dx 3 \p' J dx' Multiply by F and divide by § (c^x+cZa:) = q'dxy as before, and we have Hence the velocity of sound should be t- (jrY X v/(f ) which, though a very different expression from the former, is uniform or independent of the degree of condensation, because dx and dr are constant ; and yet it is affected by the intensity or degree of condensation, because g is so affected. We have thus, even when working more correctly, obtained a result which is evidently contradictory or absurd. Nor can it be admitted as an excuse, to say, that § and §' are nearly equal ; for we have already seen that the principles acted on in this investigation imply that p may exceed p' in any proportion, dx By using unit for the index of , we do not, when •' ^ dx+dz nothing is omitted, obtain Newton's result, as Mr. Ivory alleges, but the very different expression which is just as absurd as the other. Indeed, when in this mode of investigation, none of the powers of dz have been rejected, the velocity can never come out uniform or independent of the degree of condensation, and be at the same time real or possi- ble. For, taking the only two supposable cases, — were the index = 0, neither the elasticity of air, nor sound, which de- pends on it, could exist; and were the index = — 1, the elasticity would vary inversely as the density, which is a perfect contradiction, not to mention that the velocity of sound would come out an impossible quantity. Any further evidence would be superfluous to show that this sort of investigation is not only inefficient, but full of error and incongruity, view it which way we will ; and that it will be K2 132 Mr. Meikle on the alike unfortunate for this theory whether the motion of sound ultimately turn out, from experiment, to be uniform or retarded ; for, independently of that, the result is anything but a fair logical deduction from correct data. I have as yet confined my remarks to Mr. Ivory's investigation in the Phil. Mag. for July, 1825. His other solution grafted on it, and given in that Journal for April 1827, is one way or other liable to all the abovementioned objections. The difference between his two solutions is owing to the innovations of his new law of con- densation — an extraordinary production — the result of at least seven years' researches on the subject *. So far, however, from its being the lie plus ultra of science, as we should have reasonably expected, and as its author has more than once hinted, I doubt if, in point of absurdity, the like has been put on record since the dark ages. A few cases, where it leads to most erroneous results, are noticed in the Edin. Phil. Jour. for April, 1827 ; and I shall now state the law briefly, with an example or two of its unparalleled absurdity. Let r be the temperature on Fahrenheit's scale of an air- thermometer, when a mass of air begins to undergo a change of density ; and § the quotient obtained by dividing the density at the end of the operation by that at the beginning. Then, according to Mr. Ivory, the change of temperature due to such change of density is i - A (448° + t) X ^^. 8 p Among the many extravagant and contradictory conclusions to which this new law leads, there is an obvious one notoriously at variance with observation, — that no compression could raise the temperature of air from the freezing to the boiling point of water ; for, the greatest number we can substitute for §, will always bring out i less than 180°, with r =i 32°. Hence, were all the air which invests our globe condensed into a point, its * During the long period in which Mr. Ivory wrote on this subject, it is curious to observe that, thous^h he is always right, and every one else wrong, he is incessantly changing his creed without giving the reason. Accordingly, this new law of condensation comes forth in February, 1827, without the least hint that the law of July 1825, was either repealed, or had ever existed. Velocity of Sound, 133 temperature could not be thereby raised from 32*^ to 212° ; nor could the ignition of tinder be caused by the heat evolved from air on its being condensed. But though such results be out of all shape, yet the law now stated is, if possible, still more at variance with itself than with facts ; for we soon obtain a very different result, by taking the condensation at several successive steps. Thus, by doubUng the density of air at 32° Fah., or putting t = 32° and g = 2, we obtain i = 90°, which raises the temperature to 122°, Doubling again the density with t = 122° and § = 2, we get i = 106°.875. The density has thus been only quadrupled, and yet the rise of temperature, viz. 90° + 106°.875 =: 196°.875, exceeds the rise due to compressing all the air of the atmosphere into a point, at one operation *. I may remark, by the bye, that so far as is yet known, an elastic fluid cannot be liquefied by condensation, if it lose no heat. If the air, which, by having its density quadrupled, has attained the temperature of 228°.88, be now restored to its original density, ought it not to be, in every other respect, re- stored to its former state ? and, in particular, if it have neither gained nor lost heat, ought it not to resume its original tempe- rature of 32° ? So far, however, from this being the case^ we shall find that by restoring the original density, the resulting temperature will be lower than 32° by the enormous quantity of 564°.6. Thus, putting r = 228°.88 and /? = -^ , (for the law being general, must suit any initial temperature or den- sity,) we obtain i = — 76I°.48. Hence, in place of 32°, the resulting temperature is 228°.88 - 761° 48 = — 532°.6 Fah., or 84°.6 below the absolute zero of those who, with Mr. Ivor}^, insist on an air-thermometer being the standard ! What a striking contrast between such absurdities and the following formula, in which not the slightest inconsistency can be detected, viz. i = (448° + t) (p^ - 1). * It is obvious that we may proceed in strict conformity to this law, and yet vary the result considerably ; nay, in some cases, enormously, at pleasure, according to the number or magnitude of the parts into which we subdivide the whole change of density as taking place at successive steps, 134 Mr. Meikle on the This Mr. Ivory has rejected, without showing cause why. Most probably he did not Hke it after it was well known not to be his own production, and especially after I had advanced so much in its favour. Except the index of 5, it is M. Poisson's formula. The reasons why that index should be ^ are given ia Edin. New Phil. Jour. vol. ii. 333, 391, and iv. 101. I formerly remarked that the notes of music afforded no satisfactory proof that sounds of all intensities are propagated with equal velocities. Another alleged proof, apparently of more weight, has been drawn from the experiments made in France in 1822 ; where the velocity of sound appeared to be the same, whether the guns were charged with two or with three pounds of powder. When, however, as was the case there, the powder has almost nothing to propel, a considerable proportion of it escapes without catching fire, and so much the more as the charge in the same size of gun is greater : so that the re- ports from the two and the three pounds of powder, might not differ materially in sharpness. Nor can I attach any stress to equal or uniform velocities deduced from hypothetical data ; for we have seen that one of the most natural and obvious in- ferences from the projectile theory just discussed, is that the velocity ought to decrease rapidly ; which is curious enough when we recollect that those who follow this mode of investi- gation assume, without hesitation, that it accords with a uni- form velocity. No solution of the problem can be legitimate, if it take for granted an element so important, but so dubious, as uniformity of velocity, — an element which, I presume, can only be settled by experiment. For, I think it will be found that in solutions of this problem, the uniformity of the propa- gation of sound, or its independence of intensity, is, at best, assumed, or not provided for. In some cases, as we have seen, it may be got over quietly by inaccurate working ; by re- peatedly rejecting terms from the calculus, without giving any good reason, or showing that such terms could not have influ- enced the result. If the velocity of sound be really greater when it is more in- tense, then all attempts to bring out a legitimate and definite mathematical result must necessarily prove abortive ; because the intensity, being of an indeterminate character, cannot^ as Velocity of Sound, ]8§ the supposed case would require, be made the basis of mathe* matical investigation. The great Euler, to whose sagacity we owe so much, was of opinion that the motion of sound is affected by its intensity. Lagrange, however, thought it easy to show, from theory, that this could not be the case. But, besides the particulars noticed in the present article, the cir- cumstance, which I formerly mentioned, of wind exercising such an absolute control over the intensity of sound, and which our refined theories do not recognise, sufficiently shows how little confidence is due to theory in any such matters. The excess of the velocity of sound, aided by a very faint breeze, while passing from Montlhery to Villejuif, on the 22d June, 1822, over its motion on the preceding day, rather favours the opinion that wind adds more than its own motion to that of sound. Further experiments are, however, wanted to decide this point. Description of a Regulating Valve for a Gas Establishment, 10] t Mount- Street , Grosvenor- Square, Sir, August 2dth,] 828. The continued and increasing employment of gas, as a source of artificial light, confers a value upon every means which renders its distribution more convenient and economical. As the consumption of gas, during the night is variable, it is desirable that the pressure at the gas-station should be regu- lated according to the demand. I have obtained from Mr. Eastwick (the very intelligent engineer of the Bath gas works) a description of a valve which enables him to adjust the flow of gas into the " main," so as to ensure an economical, yet suffi- cient, supply to the burners at the different periods of the night. If you think it deserving a place in your Journal of Science, it is much at your service : I therefore enclose it for your ap- provaL I am, Sir, yours, truly, R. Addams. To IF, T. Brande, Esq. « Sir, " Gas Works, Bath, June 1st, 1828. '• Agreeably with your request, I send you a drawing of the index of a regulating valve, which I placed on the eight- 136 Regulating Valve for a Gas Estahlishmmt. inch main pipe leading from these works last summer, and which I had the pleasure of showing to you when you were in Bath in January last. " The valve consists of a circular plate of metal, nine inches in diameter, sliding over the mouth of the main pipe, in a chamber. The face of the index is a representation of the valve itself; so made in order that the superintendent may know the precise position of the valve at any time. '* The black disc A is a thin plate of metal attached to a rod coming up from the valve behind the index frame, in which there is a slit for the pin which carries the index to pass. \ The portion of the circle B, which is uncovered by the disc, repre- sents the aperture, or gas-way into the main pipe. D is a pressure gauge connected with the main on the gasometer side Regulating Valve for d Gas Establishment. 137 of the valve, and C, another pressure gauge, also connected with the main on the town side. " There is a burner, supplied from the town side of the valve, placed before the eye of the person who adjusts the valve. '• From repeated inspection of the town lights at all hours of the night, as well as of the burner before the index, the re- quisite pressure is known and regulated ; as the night advances, the valve is lowered more and more, and in the morning (when the lamps ought to be all out) it is depressed to one-tenth of an inch ; that being sufficient to cause the exit of the gas in the lowest situations. *^ The operation of the valve is so well understood, that I have been enabled to leave the management of it to the work- men ever since its erection. *' By this simple, yet effectual, contrivance, the saving of gas has been very great. , *' I have never had occasion to elevate the valve more than -j2^*(jths*, as shown in the drawing, this being sufficient for the escape of upwards of 7000 cubic feet of gas per hour, without the pressure of the gas being reduced more than -ji^th of an inch, (viz. from one inch to -j-yhs after it has passed the valve.) '^ I believe you are aware that, from the nature of the coal used at this establishment, the retorts, after much use, become lined with a hard carbonaceous substance, of so considerable a thickness, as to diminish their capacity to one half and less, on Avhich account a larger number of retorts u'as required ; and from the imperfect conducting power of this incrustation, the decomposing process was slower, and additionally expensive. I am happy to inform you, that I have perfectly succeeded in removing the incrust in the following way : the retorts are left open, and kept at a good heat, by which the carbonaceous lining undergoes slow combustion, and in the course of a week, or more, according to the thickness, it is entirely burnt away. ^' Believe me to be. Sir, " Very respectfully yours, " W. H. Eastwick." '* To R. AddamSy Esq" t When the area of thelunaric aperture is]= 14.733 square inches. R. A, 138 Transactions of the Horticultural Society, Vol. vii. Part II. 4to. London, 1828. [Continued from No. III. p. 175.] The following are the principal contents of this Number, which is illustrated by four copper-plates, two of which are coloured, and many wood engravings. XXIV. Account of a Mode of managing Peach Trees in an early Peach House. By Mr. Walter Henderson. Of all the fruits that are forced into bearing at unseasonable periods, the peach is one of the most delicate, and which re- quires the greatest care and good management. Mr. Hen- derson, who has the reputation of being unusually successful, states, that the mode of treatment he adopts is the following : — The trees are trained on trellis-work at a short distance trpm the glass ; the house is warmed by a single flue running along the middle of the house ; and by a pit between the flue and back wall, filled with decayed leaves, which are continually impart- ing moisture to the atmosphere. The house is shut up about the first of December, and either gently warmed by fire, or not, according to the state of the weather. As soon as the buds swell, as much as possible of the wood that bore the previous season is cut away, and the younger shoots are tied into their places ; not having previously been interfered with, but allowed to grow wild. The best shoots being selected, they are shortened according to their strength, care being taken always to cut them down to a leaf hud. The shoots are eventually laid in at the distance of from six to nine inches, and a great number of flower-buds are rubbed off", the strongest only being allowed to expand. As soon as the peaches are set, their leaves are gently sprinkled in the fore- noon with water, once in every six or seven days ; about the middle of March they are sprinkled in the afternoon. By this time the trees are producing the new shoots which are to bear a crop in the succeeding year : these are reduced in number by thinning and rubbing off", none being preserved except where there is room for them ; such as are left are not tied down, but allowed to grow in their natural way, by which means the shoots on which the fruit is growing are not disturbed. As the season advances, the trees are sprinkled twice each week be- tween four and five in the afternoon ; this, however, is only done in warm, sunny weather. About a fortnight after the young peaches have stoned, the sprinkling is stopped, much Transactions of the Horticultural Society, 139 more air is given to the house, and no fire-heat is maintained during the day ; but if the weather is dark or wet, a httle fire is applied at night ; if the weather is warm and dry, the house is exposed to the air all night without fire-heat. By this ma- nagement, the peaches acquire the unusual weight of half a pound each, and occasionally even that of ten ounces. The trees submitted to this treatment have undergone the same process for twenty-seven successive years, and are still in good health. XXV. Remarks upon the Comparative Advantages of Grafting Pears upon Quince Stocks. By Mr. Thomas Torbron. It is a well known law in vegetable physiology, that in propor^ tion as leaf-buds, or as Darwin called them, viviparous buds, are produced by plants, flowers, or oviparous buds, cease to be developed, and vice versa. Hence it is obvious, that whatever has a tendency to check the former, and favour the produc- tion of the latter, is beneficial to gardeners. Practice has shown that, by grafting fruit trees upon one kind of stock, the ten- dency to produce leaf-buds is increased, and that other stocks exercise a contrary influence. Gardeners in this country have long been well aware how to apply these facts to the cultivation of the apple, but they are little acquainted with the influence of the stock upon other kinds of fruits. The object of the writer of this paper is to show the benefit of grafting pears upon the quince-stock, instead of upon their own species. He states that the increase of produce by that means is on the average as 7.6 to 1 in favour of the quince ; and in one case he found it as 15.1 to 1. Pears grafted upon the quince have also the merit of not occupying so much space as others ; but it is to be doubted whether they be as long lived. XXVI. Description, with Plans, of a Hot-wall. By Mr. John Hay. Without the aid of heated walls, our friends in the North would have little chance of raising many of the good things in their gardens, which are produced with us by the climate alone. To them, we doubt not, these plans will be highly useful. They cannot well be explained without figures ; we must, therefore, refer such of our readers as are interested in the matter, to the work itself. XXVII. Report upon the New or Rare Plants which flowered in the Garden of the Horticultural Society at Chiswick, between March, 1825, and March, 1826. Part II. This is a continuation of former reports of the same nature. The present paper comprehends twenty-seven species, with 140 ^ansactions of the Horticultural Society, numerous varieties of hardy trees and shrubs, of which thirteen species, and ten varieties, are new. Several are highly inter- esting to lovers of gardening. XXVIII. On the Culture of the Mango and Cherimoya. By Thomas Andrew Knight, Esq., F.R.S. Upon a consideration of the failure which has generally attended attempts at cultivating these plants, and the circum- stances under which the mango has succeeded so well in the garden of the Earl of Powis, Mr. Knight is led to the conclu- sion, that being plunged in a bark bed, or in some similar situation, where the roots can be kept in a constant state of humidity, and not exposed to the action of the air, is the secret which it was necessary to discover. This appears to Mr. Knight to be accounted for upon the principles explained by M. Dutrochet, in his work upon the influence of galvanism upon the motions of the fluids of plants; and he does not doubt that the ill success of his former experiments arose from an excessive or injurious action of electric matter upon the roots of his plants, owing to the exposure of the surfaces of the pits to the air. XXIX. Some Account of the Mela- Carla^ Mai- Carle, or Charles Apple. By John Lindley, Esq., F.R.S. This is an account, illustrated by a superb engraving, of a remarkable Italian apple, native of the territory of the Finale, in Liguria. By Gallesio, an Italian pomologist, it is stated to ripen in September, to keep well till the following spring, and even to remain fresh till the succeeding antnmn. In October it is a pale yellowish-green, covered with a bright red on one side, and has a breaking, sweet, high-flavoured flesh ; in No- vember it becomes more tender, and finally its red colour fades a little, its green changes to a waxy yellow, its perfume dimi- nishes, and its flesh becomes extremely delicate, without losing any part of its flavour. In short, it has no equal in beauty, tenderness of flesh, delicacy of flavour or fragrance. Whether in this country it will acquire all these good quali- ties, remains to be proved. A south wall in a warm, dry soil is recommended for it. XXX. A Review of Fifty Kinds of Grapes, described by Mr. Speechly in his Treatise on the Vine. By Mr. Joseph Thompson. This is a capital review of the sorts of vines described by Mr. Speechly in his valuable treatise. Mr. Thompson has charge of the garden formerly under the direction of Mr. Speechly, and his observations have all the weight of the be^t authority. They do not bear curtailment. Transactions of the Horticultural Society. 141 XXXI. An Account of the Species of Calochortus, a Genus of American Plants. By Mr. David Douglas, A.L.S. Three species of this very handsome genus are described by Mr. Douglas, from materials collected by himself for the Horticultural Society ; one other is referred to, of which too little is known to enable it to be recorded ; and Fritillaria barbata of Kunth is cited as being probably a fifth species. The only one in the garden is C. macrocarpus, a most beau- tiful plant, having the habit of Tigridia, with flowers of the same size, but of a deep violet blue. Three species are figured — one from a plant that flowered in the Society's gar- den, and two from dried specimens. XXXII. An Account of some Improvement in the Construction of Hot- beds. By Thomas Andrew Knight, Esq., F.R.S. By means of a simple contrivance of wooden or other pipes, Mr. Knight succeeds in keeping up a constant introduction of fresh warm air into the atmosphere of the hot-bed ; a most important improvement, if we consider what the general nature is of the air of hot-beds. An Attemj)t to prove that Ava ivas the Ophir of Solomon. By John Ranking, Esq. Ophir, Aufer, Aufr, Afer *, is one of the most interesting and remarkable of the uncertainties in historical literature ; *• An ignis fatuus that bewitches. And leads men into pools and ditches t." Peru, Hispaniola, Guinea, Armenia, South Arabia, Sofala, Ceylon, Malacca, Sumatra, have all had their advocates. The last treatise is by Mr. Bruce ; who, following D'Anville and others, contends for Sofala: and which, says Dr. Robertson J, seems to establish the truth. The author of the article " Ophir" in Rees's Cyclopcedia does not agree with that eminent histo- rian ; and the writer of the dissertation in the Encyclopcsdia Britannica, equally in doubt, ends his remarks thus : Subjudice lis est. Bruce's laborious calculations regarding the monsoons are ♦ So spelt by Dr. Doig. t Hudibras. % India, p. 9, 142 An Attempt to prove that Ava found to be blunders * ; and he has confined the cargoes to gold, silver, and ivory : omitting peacocks, monkeys, precious stones, spices, almug-trees, and ebony. BufTon f insists positively that peacocks were not wild in Africa till they were introduced by the Portuguese, and that therefore Ophir could not be in Africa. Alexander the Great, when he entered India, is said to have been much struck with the beauty of the peacocks, never before having seen one J. As to the first five places mentioned above, there are obvious insuperable objections to them all. The three last have, neither of them, ever been known to possess such abundant riches and ivory as were imported by David and Solomon, Four hundred and fifty talents of gold have been brought by one fleet §. Thrones, beds, and benches were constructed with ivory. *' All thy garments smell of myrrh, aloes ||, and cassia; out of the hory palaces^. ^^ *' The houses of ivory shall perish **." "Whatever may be meant by palaces and houses, there can be no doubt that a considerable quantity of ivory was consumed. Thus it does not appear that any one of the above places is free from objection, as not being known to have produced either all the objects imported by the Jews ; nor, several of them, the great quantity of some of the articles enumerated. The writer will now endeavour to prove that Ophir, or Afer, was no other than Ava ; and if that country has always borne the name, which it now does, of Ava ft, and if it has formerly contained, or does still contain, all the articles described as forming the cargoes imported, is it not quite astonishing that that consideration and the name have never led one of the host of critics to the discovery of the undisputed truth ? Another remarkable circumstance attending that rich mart ♦ Rennell's Herodotus, p. ^7(j. t Sonnini's Edit. vol. xlii. % ^lian. § 2 Chronicles viii. 18. II This means the perfume ; it is produced in Ava, ** the aloexylum veruniy much valued for the grateful odour of its smoke." — Rees's Cyc, " Birraan." 1 Psalm xlv. 8. ** Amos iii. 15. •M' This word may be otherwise pronounced in that country j as it is spelt also Aun^wan-r-^QQ Rees's Cyc, " Ava." was the Ophir of Solomon, 143 of ancient times, is, that it was probably known to, and invaded and conquered, by landf by the Turks, not many years after the death of Solomon, as will be seen. It will now be shown that the country in question is noted for all the riches and productions with which the ships were laden. ^' Pegu, in the 16th century, was visited by Gasparo Balbi, a Venetian jeweller; and he relates that the magazines of gold, silver, Ganza, jewels^ &c., were under separate trea- surers ; and that the king was the richest in the world, except the Emperor of China. In the year 1600 the King of Pegu was slain by the King of Tangut, who laded six or seven hundred elephants and as many horses with gold and jewels ; not regarding the silver, which, with all the artillery, was seized by the King of Aracan, to an immense amount. Bonferrus relates that the Peguans are descendants of Solomon's people. The largest elephants in the world are here found in abun- dance, and also apes, parrots, and peacocks.'* See Purchas (vol. i. 33 to 40), who is of opinion that Pegu is Ophir. Ebony is produced in Ava, — the ehenoxylum verum, or true jet black kind. (Rees's Cyc, ** Birman.") Almug wood is said to be cedar, fir, cypress. (Rees's Cyc. ^' Almiggim.") Josephus describes it as " pine wood in abundance, of such great size and beauty, that Solomon had never before seen any that was comparable; not like common pine, but with the grain of the fig-tree, only rather whiter and more glossy : and that it was used as pillars and supporters of the Temple and palaces, and also for harps, psalteries, &c."* Abundance of fir-trees grow at the present epoch in the kingdom of Ava. (See Rees's Cyc, *' Birman.") Spices, Pepper of several kinds f , ginger, cardamums, tur- meric, three or four kinds of capsicum, cassia fistula, cinna- * Josephus, Book viii. ch. 11, •^ Peacocks feed on pepper. The writer, while shooting on the banks of the Luckia river in Bengal, flushed a flock of about twenty of these splendid birds in a field of grass, just high enough to hide them. A more beautiful sight can scarcely be imagined. One which he shot, had in his crop more than a hundred Chili pepper pods, the smallest and hottest kind known, The tail of the bird was full six feet in length, , 144 An Attempt to prove that Ava mon laurel, nutmeg, spikenard, all grow in this country. — (Rees's Cyc. '' Birman.") Elephants and precious stones. No country produces such large elephants ; jewels of all kinds abound in this once opu- lent region. The reader, who has any doubts on these points, may have ample evidence in the 7th chap, of the Wars and Sports of the Mongols and Romans. Josephus, speaking of Saphira whence Solomon had his gold, says that it was a country of India, and not an island, and that it is now called by the name of Aurea *. Ava and Pegu are, in Ptolemy's map, named Argentea RegiOy and Aurea Regio. The city of Pegu was anciently Sahara Civitas ; Persain, or Basseen, was Barabouna Empo- rium. Colonel Symes mentions that the analogy between the Bir- mans and ancient Egyptians, in many particulars, is highly deserving of notice ; that Phra was the name under which the Egyptians adored the sun (before it was named Osiris), and a title for their kings and priests ; and that Praw, or Phraw, in the Birman country, imports lord, and is always annexed to a sacred building, and is a sovereign and sacred title, probably the same as Pharaoh. The temple of Shoemadoo f was founded 2300 years ago J. ** The ruins of the walls of Terrechetteree are of massive thickness, and may be traced through a circuit of ten miles. The enormous masses of brick pagodas in Pegu are of imme- morial age, and approach nearer to the pyramids than any other relic of antiquity. The constant ornaments of the religious edifices are sphinxes, griffins, mermaids, and croco- diles, which are the exact symbols of the religion of the Egyp- tians. Would not this warrant the conclusion, that some * Phil. Trans. 1767, Ivii. 155. t Shoe means golden. There is also a temple called Shoedagoung, or Shoedagon. " Dagon his name, sea-monster, upward man, and down- ward y?*A;' — Milton, Book i. 462. It is well worth inquiry at Rangoon, whether the shape and rites of their god dagon have any analogy with those of the Philistines: and in this enquiry, it will be ascertained, whether there be any reference or connexion with ih^Jish found in those seas called dugong. Some curious information may probably be ol> tained on this subject. t Symes, 8vo. vol. ii. 62—76. ioas the Ophir of Solomon, 145 unknown cause exists for the similarity ? — but this is a wild hypothesis, and very little borne out by probability." (Two Years in Ava, by Captain T. A. Trant. Monthly Mev., Nov. 1827.) If is a curious circumstance that mummy is with the Birmans a favourite medicine * ; but it may possibly mean the Arabian drug so called, which is used as a medicine also. The use of the body as medicine was first introduced by the Jews f . The following subject is not necessarily connected with the above, but it is added because it is short, and probably new to most readers. With regard to the Turks, their first great hero, Oguz, appears to have been a Siberian J. The Ottomans and the Moguls of the race of Genghis Khan claim descent from him§. Oguz was the grandson of Mogul Khan, the founder of that race. The exact epoch of Oguz is obscure ; he is said to have attained the great age of 116 years. '' When Cajumars, Prince of Chorassan, died, his son Haushang was in his mino- rity, and the lords quarrelling for the reins, Oguz marched to Azerbijan, Irak, and Armeen, which countries he conquered ||.*' Caiumaras died, and Husheng succeeded to the throne, ac- cording to Sir William Jones (vol. v. 587), in the year B. C. 865 ; and this is, perhaps, the nearest approach to the know- * Rees's Cyc. ** Birman.'* + Rees, " Mummy." % Strahlenberg was informed by Tartars and Russians at Tobolsk, that to the south-west of tliat city, between the sources of the Tobol and Ischira, which few people frequented, there were great numbers of images cut in stone, of men and beasts, and that the ruins of several cities were discernible in those deserts ; and that this was the place where Oguz Khan the Great had his residence. — Hist, of Siberia, p. 4. Tamerlane, when he was in this neighbourhood, acknowledged it to be the country of Oguz. § There is a great similarity of customs and ceremonies in these two people, who have often been rivals. They have each conquered Siberia and China, and all, or part of India extra Gangem ; they both have pea- cocks as supporters for their thrones. The Chinese wall was built B.C. 221 ; and a century afterwards, Vu-ti, emperor of China, also conquered Pegu, Bengal, (probably Eastern Bangalla, described in Wars and Sports, ch. vii.) Siam, and Cambodia. He divided those countries among the generals who had conquered them ; but they soon contracted the manners of the Tartars, and became the greatest enemies of the mother country. — Du Halde, Wars and Sports, p. 89. II Abul Ghazi, p. 19. JULY— SEPT. 1828. L 146 An Aiiempt to prove thui Ava ledge of the epoch of Oguz that can be obtained ; but the chronology of these heroes and events cannot be very cor- rectly known ; nor is the exact truth in that respect of much importance in this sketch. The 7th century B. C. is generally the epoch assigned to Oguz : some, perhaps, reckon from his birth, and others from his death. Solomon is said to have died about B.C. 975; therefore Oguz would undoubtedly be acquainted with the wealth of the Hebrews, and be inflamed with the ambition to pay a visit to the country which furnished such various and abundant articles of luxury and grandeur. "The Turks had professed the true religion," says AbulGhazi, *' till the reign ofCara Khan, the son of Mogul and father of Oguz ; but at this epoch idolatry had increased so much, that the son would destroy his parent, and the father his child, who showed an inclination to return to the true worship. When Oguz was born, his face shone miraculously like the sun, and he was continually pronouncing the word Allah. When Oguz succeeded to the throne, he resolved to force the subjects of his grandfather, Mogul, to adopt the true reli- gion *. He invaded Dsurdsut (Gurgut or Zinu) on the fron- tiers of Kitay f , and the booty was immense. He was seventy-two years at war, and brought the people back to the true religion. After which he conquered the empire of Kitay J, the city of Dsurdsut, the kingdom of Tangut, and Cara Kitay §, * It is not unlikely that the introduction of the religion of Budda, or Boodh, was the innovation. Boodh was born, says Sir William Jones, B.C. 1027. The subject of Boodh's person and country is very obscure. *• He had curled hair," says Sir William Jones, " was not a native of India, and was probably Sesostris." ** I am inclined," says Herodotus, " to think that the Colchians were descended from the troops of Sesostris, because they are black, and have hair short and curling. They have also similar manners, the same languao:e, and their manufacture of linen is alike." (Euterpe, civ. cv.) If the Peguans have preserved their early history, it will probably clear up some points relating to the Pharaoh's, Boodh, the Turks, and the Syrians. t In the map with Abul Ghazi, Zinu is in north lat. 32°. At this epoch Singan was the capital of Kitay, which never means more than the northern half of China. 1 B.C. 777. A torrent of Tartars distracted China. — ^Vide Du Halde, vol. i. p. 1 63. § Cara (black). Cathay is on the map in lat. 23 to 30, now partly Assam. Other territories have borne this name from the colour of the' rich soil; it may in this case designate the black people. was the Ophir of Solomon, 147 about the lake Mohill*, where tlie people are as black as Indians. From hence, passing behind Kitay, he found on the sea-coast, among the mountains, very warlike people, whose khan was called Itburac, and who, with a good army, received him so bravely, that he was constrained to go back and post himself in an advantageous camp between two great rivers. Oguz and his chief officers carried their wives with them. Seventeen years afterwards, Oguz conquered the dominions + of Itburac, and put him to death. Cabul, Gazna, Cashmere, Damascus, Turquestan, Great Bucharia, Bale, &c. fell to this great conqueror, who, at his decease, made a just distribution of his empire among his numerous relations J. By the above short essay, some perhaps may be induced to conclude that Ava was the true Ophir. With regard to the navigation, it was more approachable than some of the places mentioned ; and on that point those who have contended for Malacca and Sumatra will have nothing to oppose. The facts are too remarkable not to attract the attention of literary gentlemen in Bengal and Ava ; and further enquiries in those countries will very probably lead to curious discoveries on this question. On the Sap of the Rose Tree, Communicated by R. Addams, Esq. A FEW weeks since I had an opportunity of collecting a consi- derable quantity of sap from a rose tree, and I was induced to submit it to a chemical examination. The following are its characteristics : — It was transparent, and colourless when viewed as drops, but in large portions it appeared a little opalescent. It was tasteless and inodorous. Specific gravity 1.001. It contained no uncombined acid or alkali. * In the map, lat. 27°. t A note says this means Tonquin and Cochin China ; but the posi- tions of those countries beyond so many large rivers, seem to warrant the conclusion that Assam, Ava, and Arracan, were the territories conquered by Oguz, as has been mentioned in page 89 of " Wars and Sports ;" and this conjecture is strengthened by the circumstance of Boodh having in- troduced his religion first into AiTacan, and thence into Ava. — Bees's Cyc. " Boodh." J Abul Ghazi, (a descendant from Genghis Khan.) Vol. i. p. U,ch.ii, L2 14S On ihe Sap of the Rose Tree. Sub-acetate of lead and oxalate of ammonia each occa- sioned a precipitate. Twelve fluid ounces were evaporated, and afforded 7.25 grains of solid matter (a), which, being tested by sulphuric acid, evolved fumes of acetic acid. To this (a) water was added and heat applied, apart only dis- solved : the insoluble portion (6) weighed, when dry, 2.9 grs. ; it was not acted upon by muriatic acid. Supposing it to be oxalate of hme, a part of it = 0.3 of a grain was heated to redness on platinum foil ; it left a white powder possessing all the properties of lime. The remainder of the insoluble por- tion (6), viz. 2.5 grs., was boiled in carbonate of soda, and thus decomposed into oxalate of soda and carbonate of lime, the latter weighed 1.9 gr., containing 1.064 of lime, being, nearly, the equivalent of lime in 2.5 o( neutral oxalate, or 1.094. To the soluble part of (a) oxalate of ammonia was added, until it ceased to give a precipitate; this being separated, weighed 0.9 gr. ; it was oxalate of lime, and equivalent to 1.097 of acetate of lime in the soluble part of (a). The remaining fluid yielded, by evaporation, a brownish viscid mass ; this was digested in alcohol (sp. gr. 0.823), and it left insoluble matter, which, dried and weighed, was = 2.1 grains, and proved to be principally gum and extract. The alcoholic solution, when concentrated, gave indication of potassa, by the application of muriate of platinum ; it was then evaporated, and weighed 0.8 gr. When tested with sul- phuric acid, the presence of acetic acid was manifested. It was now heated to redness on a silver capsule, then acted upon by water, filtered, and evaporated ; it left a little more than 0.5 gr. of carbonate of potassa, equivalent to 0.7 gr. of acetate of potassa. Therefore, collecting the results, it will be — Oxalate of lime . . 2.9 grains Acetate of lime . . J. 097 Acetate of Potassa . 0.7 Gum and extractive matter 21 Soluble in alcohol (sugar, &c. ?) 0.1 Loss 0.353 7.25 On the Sap of the Rose Tree. 149. I should not have considered the foregoing of sufficient im- portance to communicate, if tliere had not been some circum- stances, relative to the collecting of the sap, which, inde- pendently, may be thought interesting, and which, perhaps, may justify my wish to see this inserted in the Journal of Science and the Arta, The tree which supplied the sap in question is the Rosa ruhiflora, growing in a garden at Hammersmith. July 29th, it was deprived of its branches by sawing off its head, leaving a stem 3J feet high, and 2J inches in diameter. I was in- formed the sap began to flow almost immediately after decapi- tation. I did not see it until the following day, when the exu- dation of the sap was so profuse, that I collected an ounce measure of it in forty minutes. The temperature of the air at the time was 67°. The saw-cut was made inclined to the horizon ; hence the fluid accumulated at the lowest part of the section, and I occasioned it to drop into a suspended phial bottle, by a piece of twine fastened to the tree in such a man- ner as to act the part of a conductor. The " bleeding" continued uninterruptedly, a few hours more than a week; during this period I procured 31 ounces, or nearly a quart ; this, together with that which escaped be- fore my attention was directed to it, and the loss by evapora- tion, probably exceeded three pints. The discharge diminished in quantity from the time 1 first observed it. The tree is now living, and vigorously protruding young shoots. Having at my disposal an abundance of sap, I repeated the analysis upon six ounces collected on the fourth day, but in- stead of obtaining from it corresponding products, it furnished, by evaporation, scarcely one grain of residuum, consisting of about 0.25 grains of oxalate of irnmnrMt. a trace of acetate of lime, the remainder being gum. ^ A third quantity = 6 ounces of the last portions collected, was also examined : in this trial the solid matter was quite equal to the last, but it differed materially in constitution, for nothing could be separated ; it was entirely gum. Some of the sap had been reserved, and by keeping, even three or four days, it is found to generate acid, its presence being detected by litmus paper ; therefore, in all similar cases, 150 On the Sap of the Rose Tree, it is advisable to examine such productions in their most re- cent condition. September 6th, 1828. Statistical Notices suggested by the actual State of the British Empire, as exhibited in the last Population Census, By Mr. Merritt. (Read before the Literary and Philosophical Society of Liverpool.) The Essay of Mr. Malthus, hke the immortal work of Adam Smith, for some years after its appearance, rose slowly and almost imperceptibly into public estimation. Like its great precursor, it has at length attained the dignity of a class-book, and is now studied in schools and colleges ; quoted by sena- tors, and appealed to by writers, as an authority which scarcely any living author has hitherto reached. I am far from doubt- ing the grounds on which this consent of public opinion has been obtained. I am satisfied that he has made out his main propositions with a certainty more nearly approaching to the demonstrative evidence of the exacter sciences, than can often be attained, or, indeed, expected, in subjects which are in their nature so controvertible. I am equally forward to admit that his dignified and dispassionate candour is equal to his clear and logical precision. The arguments of Mr. Malthus, how- ever, it is well known, have been repeatedly and violently opposed, both here and abroad. It would have been wonder- ful if they had not. When we consider that the most assi- duous and persevering research of some of the ablest men in Europe have scarcely established a single axiom in political economy which is not disputable, it is less surprising that his system has been attacked, than that his opponents have been so few and feeble as scarcely to merit the trouble of refu- tation. This concession, however, is to be understood as applying only to the leading positions on which the system is founded : such as the natural tendency of population to increase beyond the ratio of subsistence ; the consequence of this disproportion ; and the inevitable alternative of preventive or positive checks, Actual State of the British Empire. 161 such as he has described. These principles being founded on the very constitution of human nature, I should suppose can never be shaken by any future discoveries or argumentations. They seem to have been at all times sufficiently obvious, and yet they have been so little recognised, that the manner in which Mr. Malthus has developed them, has advanced the science of political economy more than all the efforts of his predecessors, and has thrown broad sunshine on some of the most perplexed phenomena of civilized society. But when this gentleman begins his examination of the remedies which have been proposed for these alarming evils, and especially when he brings forward his own grand proposi- tions of practical alleviation, he then, I presume, enters on more debatable ground. This observation, perhaps, might be variously illustrated ; but in the few remarks which are here loosely thrown together, I shall confine myself to two points of acknowledged importance — ^the question of emigration and the abolition of the poor-laws. From the first appearance of this great work, it always struck me, that the chapter on emigration was the vulnerable part of the book. To use a vulgar, but very expressive parliamentary phrase, he always appeared to me a little disposed to blink that essential part of the enquiry. Apparently his object is to shew that the evils which have always preceded and accompanied emigration, are necessarily greater than those which they were meant to relieve. He has made a formidable array of the obstacles which present themselves to every new settlement, and has detailed some of the most disastrous attempts of this kind, which have been recorded in different ages. He has endeavoured to shew, that in almost every conceivable case, whether the object is to colonize an uninhabited country, or a territory claimed, but not occupied by other governments, the suffering and waste of life will, in most instances, exceed the operation of the positive checks which drove, the superfluous population from home. On these grounds, therefore, emigra- tion is not to be considered as a remedy, but as a substitution of one evil for another equivalent to it, with the gratuitous trouble and expense of a change of residence. But these conclusions are not inevitable. The sufferings 152 Actual State of the British Empire, which usually attend the formation of a new settlement may be avoided or mitigated by that degree of prudence and fore- sight, without which no difficult undertaking can be expected to prosper. As the relief of an excessive population is a na- tional affair, all governments are bound to consider it as such, and no expenditure of their revenues can be more useful and legitimate than that which is employed to maintain the due proportion between the number of the people and the means of their subsistence. It ought, therefore, to be a standing object of national policy, to provide the resources, and facili- tate the means of a periodical emigration. Being thus in con- stant readiness, whenever the symptoms of a redundant popu- lation begin to manifest themselves, they can be promptly ap- plied, before the positive checks, with all their horrible train, have made much progress. Most of the disasters which Mr. Malthus enumerates were the necessary effect of insuffi- cient means, defective information, or rash enterprise. Many of the obstacles, moreover, which oppose or retard the esta- blishment of new colonies, have disappeared, by the progress of colonization itself In those parts of the world which admit and demand the greatest increase of inhabitants, the difficul- ties which attend a first settlement are already subdued. These communities then become strengthened by the admixture of new settlers, and the population diff'uses itself by the mere expansive force of additional numbers. It is sufficiently demonstrated that there exists in mankind a power of increase far beyond what was wanting to keep up their numbers to any stationary amount. Mr. Malthus not only admits but maintains that this prodigious power was given for the purpose of replenishing the earth ; which, from reason and revelation, we have every reason to believe was originally peopled from a very small number. He there- fore cannot deny that the command of " increase and multi- ply" is of human as well as of divine obligation, so long as any considerable parts of the earth remain unpeopled. Yet so imperfectly has this command been hitherto obeyed, that there is reason to suspect that no progress whatever in replenishing the earth has been made for the last 2000 years. Is not this U; palpable contravention of the plainest designs of Nature ?ind Actual State of the British Empire, 153 Providence ? Do we not wilfully retard, if we do not studiously promote the great scheme of creation, if we omit to furnish inhabitants wherever the means of sustenance are found ? Does it not indicate some gross defects in human contrivance, when we contentedly labour under the dreadful ills of a redun- dant population, at the time when the greatest part of the habitable globe is wasting its annual produce in the desert air? But projects of emigration on a large scale, it will be said, would entail on governments such an intolerable expense, that no nation would be willing to endure it. It is lamentable that the imbecilities of human management should thus encounter us at every turn. What an inconsiderable part of the sums habitually wasted in the pursuits of national ambition or resent- ment, would gradually people all the wilds of America and Africa ! But as these diseases of our nature are, perhaps, to be reckoned amongst those which are the most desperate and incurable, it would not be wise to found any scheme of exten- sive good on the prospect of their removal. There is no need to reckon on any such chance of improvement in public affairs. Under the actual circumstances of the European nations, the means of carrying off their superfluous population might be provided without any sensible addition to their public burthens. But the horns of Mr. Malthus's dilemma encounter us on every side. Supposing, what he is far from admitting, that all the herculean difficulties of this scheme of emigration could be finally surmounted, you only remove the evil for a century or two. It then returns upon you with more force than ever, because it is universal and illimitable. It is undoubtedly true^ that the enemy, though defeated, is not destroyed : though driven from the field at present, it is only to recover strength for another struggle. But admitting this, we obtain, at all events, an indefinite postponement of the mischief; and when at last it actually approaches, and the world is completely filled, it will then be time enough to debate on the application of hazardous or desperate remedies. May we not hope that the same Providence, which gave to the fructifying power of man its superabundant energy, will provide in the progress of human civilization some remedy for its excesses. As this progress, when once in activity, proceeds with an accelerated motion, we 154 Actual State of the British Empire. may expect that the lapse of two or three more centuries will produce effects on which, at present, it is impossible to calcu- late. Before that time, we may hope that universal diff'usion of instruction will enable mankind more effectually to under- stand their interests, and to regulate their passions. It is also probable that an increased taste for luxuries, and an improved sense of enjoyment, will render men more fearful of poverty and its consequent privations. They will then act more on foresight and calculation, and when that spirit is once aroused, the busi- ness is accomplished. In fulfilling the grand primeval command of replenishing the earth — the express injunction of nature and revelation — there can be no doubt that the countries already peopled would be greatly benefited by the new nations which they successively sent out. The young and vigorous offspring would generally improve on the parent stock. The science of government, which is more in a state of infancy than almost any other, might be advanced, like the rest, by repeated and success- ful experiments. A degree of enterprize in this particular, which old states are afraid to hazard, can be undertaken by new governments without material danger. They are not encumbered by old, and corrupted, and feudal institutions, or checked by the fear of a wealthy aristocracy, or alarmed by the clamours of an ignorant populace, pent up in large cities. Besides these advantages, they start with all the lights, and all the experience of the mother-country, and of all other coun- tries. In a society where the population is no where dense, where few are discontented and none are superfluous, the greatest degree of practical freedom may be safely essayed. We see this in the instance of America. A degree of licen- tiousness which would endanger the safety of an European state, is there found to be very compatible with public tran- quillity. Her remote position, her security from hostile attack, her superabundant produce, and her consequent exemption from many of the vices and miseries of an old nation, admit a relaxation of vigour in the government, which in the perilous politics of modern Europe would inevitably prove fatal. In general, I very greatly admire the government of the United States ; but it cannot, I think, be denied, that the superior Actual State of the British Empire, 155 happiness of their people is more to be ascribed to these circumstances than to anything in their positive institutions. I shall now, in the second place, say a few words on Mr. Malthus's great remedy for the magnitudinous evil which he has so ably displayed — the gradual abolition of the poor-laws^ The authority of this eminent writer, and of some distinguished individuals, in and out of parliament, who have adopted his doctrines, have propagated a general belief that the system of our poor-laws is the great radical evil of the country. After all the other trials which we have suffered and survived, this domestic sore is, it seems, that which is destined at last to con- sume our vitals : our system of parish relief is described as a sort of hydra, with a power of self-propagation so prodigious, that it must soon lay waste the whole land, and finally leave nothing to be devoured. All the mighty evils inseparable from the principle of population are, according to Mr. Malthus, in- creased by this system to a degree of tenfold aggravation. By it all the benefits of the preventive check of moral restraint in respect to marriage are stifled at their source. Yet by this alone can the multiplied horrors of the positive checks of vice and misery be prevented or retarded. No man, it is said, will be induced to put any restraint upon his inclination when he knows that the parish is bound to maintain all the children which his improvident marriage may bring into the world. For the same reason he never thinks of making any provision, in seasons of youth and prosperity, for those of adversity and old age. The increase of parish paupers diminishes their sense of shame, and degrades their habits of independence ; and the disease in this way, like a conflagration, extends itself on all sides, and gathers strength by every extension. The Report of the House of Commons labours to show that the theory of Mr. Malthus is more than borne out by fact and experience. They infer, from the rapid increase of the poor's- rates, which they describe to be in an accelerated ratio, that they must gradually absorb the whole property of the country, convert us into a nation of paupers, and finally reduce the functions of government itself to those of overseers and church- wardens. In confirmation of this alarming doctrine, they produce instances of some parishes where the rent of all the 156 J dual State of the British Empire. land is insufficient to support its poor, and where the soil has consequently been abandoned. It is not at all surprising that these reports have spread an universal anxiety, and a general sense of insecurity amongst persons of property. Every pro- ject for the abolition of the poor-laws is, of course, eagerly entertained. It will not be difficult to show, without much consumption of time, that these apprehensions are as much exaggerated as the remedy they would suggest is inapplicable, unjust, and im- practicable. The whole argument rests on a hollow founda- tion. About a twelvemonth ago I transmitted to a periodical work a statement respecting the gradual rise of the poor- rates, in which I endeavoured to show that the public were under great misapprehensions on this important subject. My object was to prove that the augmented amount of the poor- rates was not more than commensurate with the change in the value of money, and the increased amount of our population, especially of that part of our population which nourishes and sustains the mighty mass of pauperism. This position I en- deavoured to support by a comparison of the sums expended on the poor, the value of money, and the extent of the na- tional population, at a period of forty or fifty years ago and at the present time. These points, however, have been stated with much more accuracy and detail in a pamphlet published a short time since by a gentleman of the name of Barton, Adopting as a datum what I presume will not be disputed, that the value of money is to be estimated by the relative price of corn, he has reduced the contribution of every indi- vidual to the poor-rates into its proper value in Avheat, and has found that the charge per head on the whole population of the realm was, in 1776, forty-four pints of wheat ; in 1785, fifty-three pints of wheat ; and in 1815, fifty pints of wheat. There is, therefore, a small advance from 1776, but a decline from 1785, in the real relative amount of our assessments to the poor. But this statement, striking as it is, does not by any means show the extent of our misapprehensions. It is well known that the late rapid increase of our population has taken place principally in great towns, or in manufacturing and com- Actual State of the British Empire. 157 mercial districts. There is great reason to believe that (he rural population has been nearly stationary; for though the cultivation of wastes, and the inclosure of commons, have necessarily caused an increase of agricultural employment, yet the reduction of small farms, and the improvement of ma- chinery and implements, have diminished the demand for manual labour. Our increased population, therefore, has arisen in those classes of the community in which the seeds of poverty and misery most naturally take root. In almost all the districts of the country, purely agricultural, the poor-rates are comparatively low. The true inquiry, therefore, would be, not whether pauperism has increased, with reference to the entire mass of our population, but whether it is increased with reference to that part of it which furnishes the regular supply of indigence. On that comparison, which is strictly fair, we may safely assert that it has not increased ; but, on the con- trary, very considerably diminished. Yet it is on this false assumption of the rapid and constant advance of the poor-rates, that Mr. Malthus, and a majority of the members of both Houses of Parliament, have founded their alarming list of grievances, and their still more alarming remedies. The irfundamental propositions are — that our system of parochial relief tends, inevitably, to create and extend the evils it professes to remove ; that it destroys all self-respect, and extinguishes the spirit of independence amongst the poor ; and that pauperism, when thus sustained, possesses an in- herent power of self-propagation so immense, that it must soon swallow up the great bulk of our wealth, power, and popula- tion. Mr. Malthus, who usually applies all the phenomena of society to his great problem, maintains, as I have mentioned before, that all the evils of a redundant population derive their worst aggravation from this source. The simple statement just exhibited will show, on the con- trary, that all these calculations and anticipations are purely illusory. The relative portion of our collective w-ealth, devoted to the relief of the poor, is not increased, but diminished. The self-dependence of the poor, and their salutary terror of overseers and workhouses, is noty if we are to believe the evi- dence of facts, extinguished, or even impaired. There is no 158 Actual State of the British Empire, reason to infer, from past experience, that the poor-laws ope- rate as a bounty on pauperism ; that the prospect of reUef creates the necessity for it ; or that our support of the poor furnishes the supply of poor to be supported. Is it not per- fectly astonishing that enlightened men can found such infer- ences as these, and a thousand others, on an inattention to two circumstances so well known, as the change in the value of money, and the amount and character of our population. If these opinions were purely theoretical, and, like a new system of geology or cosmogony, framed merely to occupy the speculations of retired philosophers, they might be safely com- mitted to the lapse of that dull oblivious stream which swal- lows up, in turn, the errors of successive ages. But such tenets as these are neither intended nor calculated to lie idle. Mr. Malthus boldly proposes to found upon them the most important innovation that was ever attempted in civilized society, and it is plain that the House of Commons are fast arriving at that state of mind which can contemplate it with- out horror. He would instantly commence a gradual, but complete, abolition of the whole system of poor-laws, by a public declaration, that no child, born after a given period, should be entitled to parish relief, in any case whatever. He thinks this would strike at the root of all the existing evils. By recreating a spirit of self-dependence, and by deterring the> indigent from improvident marriages, it would bring his pre- ventive check into full activity. The prevalence of moral restraint would then diminish so materially the existing stock of poverty and misery, that private benevolence would easily supercede the necessity of public relief. But before we determine upon this desperate project, we must prepare our minds and our senses for such trials as they have never yet undergone, even in contemplation. We must prepare to see our fellow-creatures perish befoje our eyes, by thousands, of famine and disease. The idea, that the prospect of parish relief operates as an incentive to marriage, or that the removal of all such hopes would act as a restraint upon it, are, in my opinion, equally fallacious. It would be quite as vain, I believe, to ex|:)ect from that source any considerable improvement in the moral conduct of the poor, or in their Actual State of the British Empire. 159 economical and prudential habits. If I may presume to men- tion the result of my own experience amongst the poor, which is not inconsiderable, I should say, that the most remarkable and uniform feature by which they are characterized is their reckless and incorrigible improvidence ; — their total inattention to the casualties of futurity. Speaking on sober calculation, I do not believe that any reflection on the existence or aboli- tion of the poor-laws would, in any important point, influence the conduct of a poor man in one case out of a thousand. Dr. Johnson's jocular account of the matter is, I believe, after all, pretty near the truth. ** I am already as poor as I can be," (a young man says to himself,) " I cannot possibly be any worse, and so Fll even take Jenny." I would not, however, omit any justifiable means of augmenting and extending the preventive check; for though a system of emigration should, be organized, complete in ail its provisions, yet before this dernier expedient is resorted to, much previous suffering will always be endured. The suggestions of our townsman, Mr, Henry Booth, on this point, are highly deserving of attention* The necessity of restraining from such marriages as do not afford a reasonable prospect of providing for a family, ought, he thinks, to be inculcated by every practicable means, as a moral duty of the first class. He would have it enforced from the pulpit, and from the press ; by private remonstrance, and public exhortations. None of these means, perhaps, ought to be rejected ; but from none of them is any consider- able effect to be expected. They must be estimated at a very small amount in any public or legislative measure which may hereafter be adopted. The support actually awarded to the poor, though enormous in its aggregate amount, is barely sufficient to preserve them from immediate starvation. I use the expression immediate starvation, because it is not sufficient to prevent them from perishing by that lingering and imperceptible decline, which is frequently induced by excessive privations. Besides this scanty allowance, there is no other alternative but the work- house ; and their horror of both is so great, that, with respect to prospective influence, an entire abolition of parish relief ■would scarcely act upon their minds with any additional force. 100 Actual State of the British Empire. A young couple, who marry with the ardent hopes and san- guine temperament of youth, disdain to contemplate the pos- sibility of ever being reduced to depend on any other help than their own. It is a matter wholly aloof from all their cal- culations. But the worst feature of Mr. Malthus's innovation is, that it reduces to one indiscriminate mass of immediate distress the profligate and the industrious ; the young and the old ; the sturdy beggar, and the blind and crippled mendicant. On this sweeping plan, a family, whose whole life has been an incessant course of steady industry, and who, on the approach of old age, are deprived of the fruits of their earnings by unfore- seen misfortunes, and rendered incapable of labour by growing infirmities, are entitled to no more support from the country they have served and enriched, than the desperate spendthrift who never looked beyond the gratification of his appetites. The destitute widow, the hapless orphan, lameness, blindness, mental imbecility, casual insanity, and all the other innumer- able infirmities of our common nature, which reduce the strength of manhood to the feebleness of infancy, are to be condemned to slow starvation, or to the forlorn hope of casual benevolence. I am well aware that any attempt to appeal to the charitable sympathies of our nature, in such a discussion, would be idle and impertinent. This grave question is not to be examined as a matter of feeling, but of calculation. I wish to make no appeal but to the results of plain facts and obvious experience. The efforts of private charity, it has been alleged, would become so much more active and extensive by the abolition of the poor-laws, that they would quickly be found an efficient succedaneum for that pernicious system. There is, it has often been said, a fund of benevolence in the British nation, always adequate to every claim upon it which may successively arise. That this fund is very great, and that it seldom fails to rise with the occasion which demands it, I have had sufficient opportunities of witnessing. Without such an aid, many of the parishes of this kingdom, in the fatal winter of 1816, must have been half depopulated. But this resource is, in its very nature, precarious and incidental. As an auxiliary it may Adaai State of the British Empire. iCl safely be depended on, but not as a principal. ** He that runs against time,**' says Johnson, " has an antagonist not subject to casualties ;" and the same may be said of him that strives against want. The supply and the demand being totally differ- ent in their nature, can never be made to quadrate with each other. They are things which are not in the same category. The most benevolent temper will become wearied of applica- tions perseveringly continued, or impatient of claims which are never remitted, or negligent of wants which are diffidently urged. To count upon such a resource, as a regular and never-failing supply, correspondent to the cravings of human wants, would argue a gross ignorance of human nature, and of civilized society. In rural situations, where every individual instance of distress obtrudes itself on the notice of the neigh- bourhood, it might happen that private charity would often be found adequate to its object ; but the case would be far other- wise in great cities. It is in these vast receptacles of poverty and crime that we are to seek for the deep and fathomless recesses of human misery. It is there where poverty retires to its cellar or garret to perish unseen ; where no eye witnesses its decline, and no ear listen to its complainings. In great towns, the most unquestionable and self-evident claims could never depend on receiving that regular supply which, to the human frame, even for its essential wants, is absolutely indis- pensable. But to all these objections, and many others which might be urged against the abolition of the poor-laws, a triumphant answer is given, by appealing to the instance of Scotland, and many other countries where no such system has ever been introduced. Here, say they, is a direct appeal to fact and experience, the only test which that class of reasoners who call themselves plain, practical men, will admit to be valid. That fact and experience are the surest guides of human con- duct no one will attempt to deny ; but we must always be sure that the experience we cite is applicable to the case in question, and that the facts which are forced into comparison are really analogous. The case of Scotland is, in many impor- tant respects, a complete anomaly in the history of nations. The system of parish education there established, diffuses JULY— SEPT. 1823. M 162 Actual State of the British Empire, amongst the lower classes those habits of mental application and moral restraint, which produce in manhood a character of prudence and self-command ; for the sacrifice of the present to the future is at once the object and the means of all just educa- tion. This admirable institution, which has no parallelin ancient or modern times, could not fail to produce its proper effect, till the period when Scotland became a commercial and manufac- turing nation. This is the true source, " Hinc illae lachrymse'* of parish taxation. A vsystem of poor-laws grows as naturally and necessarily out of the body-politic of a great commercial state, as fungi from a rich soil, or tumours from a diseased animal. This is the price and the compensation of our flou- rishing cities and our enormous trade. It is a price which can- not be evaded, without incurring the punishment which follows every gross violation of justice. In all the operations of nature, as W'cll as in the affairs of man, a system of compensation is generally cognizable, and it is no where more palpable than in this instance. I do not mean to affirm that commerce and manufactures do not produce benefits which overbalance their concomitant evils, but merely to affirm that we cannot expect to receive these advantages pure and defecated. They not only, in their periods of prosperity, force up population beyond its natural level, and plunge it into distress by their perpetual vicissitudes, but they introduce every species of habit which is adverse to sober calculation and moral restraint. The great masses of people which they necessarily congregate, ferment with the leaven of intemperance and licentiousness, till the corruption becomes universal. Thus debihtated in body and mind, when the season of adversity arrives, it finds them for the most part helpless, and without resource. Nothing but the intervention of the poor-laws could save their families from the most wasting destruction. This truth has been made evident even in Scotland, where trade and manufactures have already begun to produce their usual effects. In most of the populous districts, municipal regulations, analogous to the English poor-laws, have been generally established, and they are constantly extending them- selves. A late eminent Scottish writer earnestly deprecates 'these fearful beginnings, and adviseS; at all hazards, to havQ Actual State of the British Empire, 163 the mischief checked in its bud. But such advice is vain, as well as pernicious. If we are determined to force the growth of our people in the hot-bed of our national wealth, we cannot abandon them in the weakness to which our processes may reduce them. I am aware of only one more consideration on this subject which is deserving of much attention. Our contest with the poor-laws, it is said, is a '* helium ad inter necionemy* and that we have to do with an enemy, which, if we do not destroy it, ■will eventually destroy us, and afterwards itself. According to the progress which the system is now making, we are told that, at no very distant period, the whole produce of the soil, and the productive labour of the country, must be absorbed ia parochial taxation. This anticipation, I presume, is sufficiently removed by the calculations in a preceding part of this Essay, by which it is shown that scarcely any virtual increase has taken place in the poor-rates during the last half-century. Some persons, who are unwilling to go the whole length of abolishing the poor-laws, and yet are alarmed at the danger which they conceive to be impending, would limit the future amount of the poor-rates to a definite sum, which should not, in any case, be exceeded. Nothing could be more cruel and unjust than such a regulation, considering the fluctuations to which the value of money and the prices of necessaries are constantly liable. If, however, it is resolved to legislate further in this very difficult subject, I should prefer a statute which enacted that no more than a certain fixed proportion (the pre- sent amount of the poor-rates, for example) of the annual rental of the real property of the country should hereafter be devoted to the support of the poor. By such a law the danger of unlimited increase would be removed, and the changes would, in some degree, be provided for, which are constantly taking place in the value of money, of labour, and of commo- dities. I suggest this idea, however, with the greatest hesi- tation, not being, probably, aware of half the objections to which it is liable ; but of this I am thoroughly satisfied, that the abolition of the poor-laws, in the present condition of the empire, cannot be attempted without the risk of greater miseries than have been witnessed in Europe since the revival M9 1G4 Actual Slate of the British Empire. of civilization, It cannot be too often repeated, that the great remedy for this evil, as for all other evils of modern society, is only to be sought for in the gradual and general education of the poor. Proceedings of the Horticultural Society. March Uh. An account was read of the manner in which an orchard of cherries belonging to P. C. Laboucliere, Esq., is protected from the attacks of birds. This orchard is of considerable extent, and is covered over completely with net-work, strained from poles to poles, which are placed among the trees ; a noble instance of a disregard of cost in effecting a useful object. A paper was also laid before the Society upon the mode of training vines at Thomery, near Fontainebleau, where the famous grapes are produced that supply the Paris market. The method appears to consist in allow- ing the plants very little room to grow either with their branches or their roots, and in keeping the latter very near the surface of the ground ; in the practice at Thomery, each vine is only allowed to occupy a space of about six feet, so that the walls are supplied by a multitude of plants instead of by a few, as with us. Several interesting varieties of seeds and cuttings were distributed ; and the table was covered with a profusion of flowers and fruit. Among the latter, the most remarkable were some oranges from the open air, which had been produced in the garden of the Rev. J. L. Lus- combe, upon trees protected in the winter with nothing more secure than wooden shutters. March ISth. A paper by Mr. Sharp was read, upon the advantages of heating hot-houses by the combination of steam and hot water. This it was proposed to effect by introducing steam pipes into troughs of water, by which means larger masses of heating fluid might be prepared at very considerable distances from the boiler. It was anticipated that in this method the advantage of permanent heat, which is attendant upon the use of hot water, might be com- bined with the power of heating rapidly and at points far more distant from the boiler than is practicable with water alone. The paper was illustrated by a fine model. Some asparagus of extra- Proceedivgs of the HortlcuUurat Society. 165 ordinary size was exhibited ; this had been procured in the g^arden of the Society in the open air, by heating ordinary asparagus beds with dung placed in the trenches, and putting wooden pipes about an inch in diameter over each sprout as soon as it made its appearance above ground. In this manner the shoots were twelve or fourteen inches long, and tender and eatable their whole length, a circumstance which never takes place in common culti- vation. This plan is not, however, materially better than that of forcing the asparagus in open beds with dung linings, without the use of pipes. April \st. A paper was read describing several new varieties of pears which had been raised by Mr. Knight. From this it appeared that the object of procuring fine-flavoured keeping pears, capable of bearing abundantly as standard trees, had been successfully accomplished ; of the great importance of these varieties our successors will judge better perhaps than ourselves. Fresh specimens of the fine mountain Rhododendron of India, with scarlet flowers, were exhibited ; they were from a conservatory, as have been all that have yet appeared in this country. This should convince the public that they have been deceived in supposing that this splendid variety will succeed in the open air in this country. It is true that the very name of Rhododendron seems to indicate something pre- eminently hardy, and it is also true that severe cold is endured by the Indian variety upon its native hills ; but it must also be borne in mind that this cold, which is by no means so intense as that which we often experience, universally succeeds a season the isotherial temperature of which is almost tropical. The tables were covered with specimens of other flowers, and with choice fruits. May bth. This was the first meeting after the unanimous re-election of the president and officers of the previous year. Mr. Knight was in the chair. Another f^te was announced to take place at the garden on the 21st of June. Notices were read of the award of a number of medals of the Society by provincial horticultural societies. Among the subjects exhibited was an extraordinary fruit of the Madras citron, which had been raised by Mr. Wells of Redleaf. It was fully as large as a child's head, and excited much curiosity. Jvne 3rd. Among a variety of beaytiful flowers and f^xiit, with which th^ 166 Proceedings of the Horticultural Society. tables were ornamented, the most remarkable objects were som6 specimens of Persian melons, grown in the garden of Sir Thomas Frankland. These were of great beauty, and their flavour was as perfect as we imagine melons to be capable of attaining. It was stated that they also possessed the merit of being more easily cultivated than many of the Persian melons. When it is considered how far more beautiful and delicious these kinds are than the common red-fleshed, thick-coated, indigestible varieties with which our markets are supplied, it is really matter of surprise that the latter can find either cultivators or purchasers. July \st. Mr. Knight laid before the meeting his observations upon th(i cultivation of the potatoe, the result of which was, recommending the plants to be very close in the rows, but the rows very distant from each other. He argued, that as it is a certain fact in vege- table physiology that the quantity of matter elaborated by the leaves and sent down by them towards the roots, depends upon their being exposed to as much light as they can have consistently with the due performance of their other operations, the placing such a plant as the potatoe in circumstances under which one half of the leaves is shaded and kept in comparative darkness by the other half, must of necessity be absurd. But by letting the plants be close in the rows, and the rows distant from each other, the greatest possible facility is given the plants for arranging their stems in such a way as to expose the whole of their leaves to the hght. We have no space to enumerate the endless varieties of strawberries, pines, cherries, nec- tarines, raspberries, and flowers, with which the meeting room was ornamented. July \bth. We were much struck by the model of a bee-hive, which had been received from a Mrs. Griffiths, of New Brunswick, in New Jersey. It consisted of a square wooden box, opening at the bottom, and fixed upon a framed stand ; a shallower box was adapted to the top of this, into which the bees were to work when the lower part was filled. The bottom of the box was in the figure of a truncated inverted pyramid, and sloped off" so as to drain the interior effec- tually. August bih. A long paper was read from Mr. Tredgold upon the theory and practice of applying hot water to heating stoves. The writer treated Proceedings of the Horticultural Society, 167 his subject in a philosophical, as well as practical manner, and fully described the mode to be followed of making the calculations re- quired in determining the quantity of apparatus necessary to raise a house to a given temperature. We trust to have an opportunity of saying more upon this subject when Mr. Tredgold's paper shall have been printed in the Transactions of the Society. August I9th. An account was read from Mr. Knight of the method he prac- tised in growing pine-apples without the aid of tan. It was stated from the chair that the paper had been accompanied by specimens of pines cultivated in the manner described, which were exceedingly well grown and high-flavoured. We chance to know this to be strictly true, having had an opportunity of seeing these pines ; and we have no difficulty in stating that they were not only unexcep- tionable in every respect, but very uncommon specimens of excel- lent cultivation: they were handsome, heavy, well grown, extremely high-flavoured, and remarkably tender, which last quality all growers of pines know to be the most difficult of all to attain. We were particularly glad to hear this paper read, because it served at once to silence an ignorant clamour that has been raised against Mr. Knight's attempts at deviating from the routine of cultivation which certain persons have thought fit in their wisdom to prescribe. It has been pretended that pine-apples cannot be cultivated suc- cessfully without the aid of a tan-bed, as if there were some magic in that material, or as if they had such a medium to root in when wild. Nature has provided nothing for the support of pine-apple plants but heat, fight, moisture, and the ordinary principles which all vegetables derive from the soil. These can be administered with the greatest accuracy artificially, and without a tan-pit ; all that can be said of the latter is, that it is a clumsy contrivance to do that which we can effect far better without it. It may serve to screen the blunders of gardeners, or to save them trouble on one hand, while it certainly doubles both trouble and risk on the other; but nothing can be so absurd or unphilosophical as to say that such an agent is necessary to the cultivation of any thing. 168 ASTRONOMICAL AND NAUTICAL COLLECTIONS. i. Elementary View of ifA^ Undulatory Theory of Light, By Mr. Fresnel. [Continued from the Number for April.] Of Double Refraction and Polarisation, When we throw a luminous pencil on one of the natural faces of a rhomboid of calcarious spar^ it divides itself within the crystal into two other pencils, w^hich follow different paths, and then present two images of objects seen through the rhomboid. This phenomenon has been distinguished by the name of double refraction, with many others of the same kind that are exhibited by other crystals, especially when they are cut into prisms, in order to render the separation of the images more sensible. This bifurcation of the light, however, is not the most re- markable circumstance belonging to double refraction ; each of the pencils, into which the incident rays are divided, is pos- sessed of some singular properties which make a distinction between its sides. In order to describe tlie phenomena in question with precision, it is necessary to employ, and to explain, some particular expressions. In such crystals, as exhibit the laws of double refraction in their simplest form, there is always a certain direction, about which every thing occurs in a similar manner on all sides ; and this direction is called the axis of the crystal. It must not be considered as a single line : for there may be as many axes as there may be lines parallel to each other, and yet crystals of this kind are denominated crystals with a single axis, if, in all other respects, the optical phenomena are the same in all directions round it : so that the word is merely synonymous with a fixed direction. It must be supposed that the direction of the axis depends on the crystalline arrangement of the particles of the medium, and that it must hold, with respect to the faces, or their lines of crystallize^^ Astronomical and Nautical Collections* 1 69 tioiij a determinate position, which is always the same for the same crystal, however it may be presented to the incident rays. There are some crystals in which the perfect resemblance of all sides of the axis is not strictly observed, and in which there are consequently two particular directions more or less inclined to each, which are possessed of properties resembling those which belong to a single axis in the simpler form of the phenomenon : and these are called crystals with two axes ; but we shall consider, in the first instance, crystals with one axis only, the optical properties of these being simpler and more easily understood. A plane drawn through the axis, perpendicularly to the surface of the crystal, is called its principal section. The present object not requiring an explanation of all the differ- ent manners in which the rays of light are bent by the crys- tals, but merely of their mode of propagation in these me- diums, and the optical properties which they acquire in them, we may suppose, for the sake of simplicity, that the incident rays are always perpendicular to the surfaces of the crystal, and contained in the plane of its principal section : and when it becomes necessary to study their progress in different di- rections with respect to the axis, we may imagine in each case that the surfaces of their admission and emersion are made perpendicular to these directions. This being premised, we may observe, in the carbonate of lime, which has a very conspicuous double refraction, that one of the two pencils becomes oblique to the surface when the in- cident light is perpendicular ; while the other proceeds with- out being bent, in the manner of ordinary refraction: and this ray is considered as ordinarily refracted, and the former ex- traordinarily : the pencils are also called respectively ordi^ nary and extraordinary ; and the images, which they form, ordinary and extraordinary images. A similar bifurcation takes place under the same circumstances in other doubly refracting crystals, such as rock crystal, but the separation is so slight that a considerable thickness is required to render it sensible. It becomes more easily observable, when the crystal is so cut, that the surface of emersion is inclined to that of admission, which causes the two pencils to emerge at 170 Astronomical and JVautical Collections. different inclinations, and so become further separated as they proceed. But without entering into the details of experi- ments, which establish the laws of double refraction, it will be sufficient to explain the principal results to which they have led. It is remarkable, in the first place, that, when the incident rays are perpendicular to the surface of the crystal, the de- viation of the extraordinary pencil always takes place in the plane of the principal section ; and in the next place, that this deviation vanishes whenever the pencil is either parallel or perpendicular to the axis. It has been demonstrated by observation, that when the rays are parallel to the axis they not only follow the same direction, but pass through the crystal with the same velocity ; and it is when they are perpendicular to the axis that their velocities differ the most^ although they follow the same path. The velocity of the propagation of the ordinary rays is the same in all directions : and for this reason they are subject to the ordinary laws of refraction. The velocity of the extraordinary rays is different according to the angle which they make with the axis^ and this velocity is deter- mined, in the system of undulation as well as in that of emana-» tion, from the flexure which they undergo at their admission or emersion in oblique directions, which enables us to find the proportion of the sines of incidence and refraction. The ex- periments of Huygens, of Dr. Wollaston, and of Malus, on the carbonate of lime, and the numerous observations of Mr. Biot, on rock crystal, in which the angular measures of dou- ble refraction have been carried to the greatest possible pre- cision, demonstrate that the difference of the squares of the velocities of propagation of the ordinary and extraordinary rays is proportional to the square of the sine of the angle made by the extraordinary ray with the axis, if we compute the velocities according to the doctrine of emanation, as the celebrated author of the M^canique Celeste has done : and in the theory of undulations, this same ratio is observed in the reciprocals of the squares of the velocities ; for the velo- cities are always reciprocally related in the two systems* This important law, the discovery of which is due to the Astronomical and Nautical 'Collections; 17 J genius of Huygens, affords us, as its consequences, the facts which have been explained : the two kinds of rays possess the same velocities in the direction of the axis, because in this case the sine vanishes, and the difference of the velocities increases gradually with the sine, as we go further from thq axis, until it becomes greatest in the direction perpendicular to it. This difference of velocity is positive in certain crystals, and negative in others ; that is to say, in the one class the ordinary rays advance more rapidly than the extraordinary, and in the other less rapidly. The carbonate of lime, or cal? carious spar, affords an example of the first case, and rock crystal of the second. Such being the general principles of the progress of the ordinary and extraordinary rays, we may now return to the physical properties which they exhibit after their emersion, when they are made to pass through a second crystal, capa-* ble, like the first, of dividing the light into two separate pen^ cils. It may here be remarked, that the word pencil will be employed for a system of waves separated from another by difference of direction, or simply of velocity, though pro- perly borrowed from the system of emanation, as implying v^ ^W7?t//e of distinct rays. We may first consider the state of the ordinary pencil which has been transmitted through a rhomboid of calcarious spar : and which, upon being transmitted through a second rhomboid, produces two new pencils of equal brightness, when the principal section of the second rhomboid forms an angle of 45° with that of the first : in all other positions the two pencils, and the images which they form, are of unequal brightness, and one of them even vanishes entirely when the principal sections are parallel or perpendicular : when they are parallel, the extraordinary image vanishes, and the ordinary image attains its greatest brightness ; when perpendicular, the ordinary image disappears, and the extraordinary acquires its maximum of intensity. The extraordinary pencil, on the contrary, transmitted by the first rhomboid, exhibits exactly contrary appearances in passing through the second rhomboid: the ordinary image, that it affords, vanishes when the princi- 172 Agronomical and Nautical Collections. pal sections are parallel, and becomes brightest when ihey are perpendicuLir ; and then the extraordinary image va- nishes. Thus each pencil is unequally divided, except in the case when the sections make an ancrle of 45° with each other: but when they are either parallel or perpendicular, each of them will undergo a single refraction only, which is the same with the former when the sections are parallel, but of a con- trary nature when they are perpendicular to each other. It follows from these facts, that the two pencils, produced by the double refraction, have not the same properties in va- rious directions about their axes or lines of motion, since they undergo sometimes ordinary and sometimes extraordinary re- fraction, accordingly as the principal section of the second crystal is directed parallelly or perjoendicularly to another given plane. Supposing, then, that we draw right lines per- pendicular to the rays in these planes, and conceive them to be carried by the system of waves in its progress, they will show the direction in which it exhibits opposite optical pro- perties. The name of polarisation was given by Mains to this singu- lar modification of light, according to a hypothesis which Newton had imagined in order to explain the phenomenon : this great mathematician having supposed that the particles of light have two kinds of poles, or rather faces, enjoying different physical properties : that in ordinary light the si- milar faces of the different particles of light are turned in every imaginable direction ; but that, by the action of the crystal, some of them are turned in the direction of the prin- cipal section, and the others in a direction perpendicular to it, and that the kind of refraction, which the particles un- dergo, depends on the direction in which their faces are turned. It is obvious, that some of the facts may be ex- plained according to this hypothesis. But without particu- larly discussing it, and showing the difficulties, and even con- tradictions to which it leads, when closely examined ; I shall only observe, that the differences of the optical properties exhibited by the two pencils, in directions at right angles to each other, may also be comprehended by supposing transverse motions in the undulations which would not be Asttonomical and Nautical Collections. 173 the same with respect to different directions : as they would if the particles of the medium oscillated backwards and for- wards in lines perpendicular to the directions of the rays. But it is better to abandon all theoretical ideas of this kind until we have entered more fully into the phenomena. It is not merely by passing through a crystal, which di- vides it into two distinct pencils, that light receives this remarkable modification ; it may also be polarised by simple reflection at the surface of a transparent body, as Malus first discovered. If we throw on a plate of glass a pencil of direct light, inclined to the surface in an angle of about 35°, and then place a rhomboid of calcarious spar in the way of the reflected ray ; we remark, that the two pencils into which it is divided by the crystal, are only of equal in- tensity, when the principal section of the rhomboid makes an angle of 45° with the plane of reflection, and that, in all other cases, the intensities of the two images are unequal : this inequality is the more sensible, as the principal section is further removed from the angle of 45°, and finally, when it coincides with the plane of incidence, or is perpendicular to it, one of the two images disappears : the extraordinary image in the former case, and the ordinary in the latter. Thus we see that the light reflected by glass, at an inclination of 35°, is similarly affected with the ordinary pencil, transmitted by a rhomboid with its principal section in the direction of the plane of reflection. The reflected pencil is said to be pola- rised in the plane of reflection ; and in the same manner the ordinary pencil transmitted by a rhomboid is said to be po- larised in the plane of the principal section of the crystal ; and we are obliged to say, on the other hand, that the extra- ordinary pencil is polarised perpendicularly to the principal section, because it exhibits in that direction the same proper- ties which the ordinary pencil possesses in the plane of the section. The surAice of water completely polarises light by reflec- tion at the angle of 37° ; and at the surface of other trans- parent bodies, in general, when the incidence is such that the reflected may be perpendicular to the refracted ray. For the discovery of this remarkable law, we are indebted to Dr. 174 Astronomical and Nautical Collections. Brewster. We are not yet certain whether this law is rigorously correct, or merely an approximation ; but the lat- ter supposition seems to be the most probable. At other incidences, the polarisation is only partial ; that is to say, in turning the rhomboid round, the image never wholly disappears. The images vary indeed in brightness, but their minima, which always correspond to the directions of the principal sections, do not become equal to nothing. In short, when the incident rays are perpendicular, or nearly parallel to the surface, the reflected light no longer exhibits any traces of polarisation ; that is to say, the two images are always of equal intensity in every position of the rhomboid. Many opaque bodies, which are not too highly refractive, such as marble, and black varnishes, are capable of completely polarising the rays which are regularly reflected at their sur- face ; while other bodies perfectly transparent or semitrans- parent, but highly refractive, such as diamond and glass of antimony, never polarise it completely. But the metals are the least capable of polarising the light which they reflect, even in the most favourable circumstances. It is to be re- marked, that the incidences, which correspond to the maximum of polarisation, approach so much the more to the surface as the reflective body is more refractive ; if at least we may judge by the abundance of light reflected, when the body is completely opaque, like the metals. Transparent bodies do not polarise light by reflection only, but by refraction also, and the more completely as their sur- face is the more inclined to the rays ; but it is never com- pletely polarised in this manner, unless it is caused to pass through several polarised plates in succession : and so many the more plates are required as they are the less inclined to the incident rays. Ma.lus, to whom we are also indebted for the discovery of this mode of polarisation, demonstrated that the transmitted light is polarised in a direction opposite to that of the polarisation of the reflected rays ; the one being polarised in the plane of incidence, the other perpen- dicularly to this plane. Mr. Arago has found, by some inge- genious experiments which afi*orded him a very correct test, that the quantity of light polarised by reflection, at the sur- Astronomical and Nautical Collections. 175 face of a transparent body, is always equal to that which is polarised by refraction. The enunciation of this remarkable principle may be made still more general, if we say that whenever light is divided into two pencils, without any absorption, the same quantity of light, that is polarised in the one, is found to be polarised in a perpendicular direc- tion in the other. Having now studied the principal means of polarisation, we are next to apply ourselves to the singular phenomenon presented by polarised light, when it is thrown on the sur- face of transparent bodies ; and it is to Malus also that these important discoveries are due. We have seen that the light reflected by glass at an angle of 35° was completely polar- ised : this property is universal, and independent of any anterior modifications of the light ; and, in fact, light which has been polarised in any other manner is always found, like common light, after the reflection, completely polarised in the plane of incidence. Now w^e have remarked that a po- larised pencil exhibited but one image in passing through a rhomboid of calcarious spar, the principal section of which was either parallel or perpendicular to its plane of polarisa- tion ; that is, the ordinary image in the former case, and the' extraordinary one in the other ; or the image of which the plane of polarisation coincides with the principal section : hence a pencil polarised in one plane cannot furnish, by any immediate subdivision, an image polarised in a plane perpendi- cular to it: and, generalising this principle, we must conclude that a polarised pencil, thrown on glass at an inclination of 35°, with a plane of incidence perpendicular to its plane of polarisation, is also incapable of furnishing any light polar- ised in the plane of incidence, since this is perpendicular to its own plane of polarisation : but the rays reflected at an inclination of 35° are always polarised in the plane of inci- dence ; consequently the incident pencil, which is polarised in a direction perpendicular to this plane, can afford no reflection. This conclusion was justified by the important experiments of Malus ; and in the case which we are con- sidering, there is no reflected light, the whole being trans- mitted. But if, without changing the inclination of the 176 Astronomical and Nautical Collections. plate of glass to the light, it be made to turn round the ray as an axis, and to assume different azimuths, reckoning the azimuth as the angle which the plane of incidence forms with the primitive plane of polarisation, as the word is used by astronomers : in these changes of azimuths it is observed that the reflected light begins to appear the more sensibly as the plane of reflection is further removed from that which is perpendicular to the former plane of polarisation : there is a maximum when it becomes parallel to this plane, and then the reflection diminishes till it disappears entirely, after half a revolution of the plate round the ray. These phenomena are evidently analogous to those which have been observed in each of the two images produced by a polarised pencil which passes through a rhomboid of calca- rious spar, when it is turned round the ray. It is also by the same formula that Malus has represented, in both cases, the variations of intensity of the images and of the reflected light. If we apply the character i to the angle formed by the primitive plane with that of reflection, or with the prin- cipal plane of the double refraction to be considered ; and if we call the maximum of brightness unity, the brightness of the image and of the reflected light will both be expressed by cos H. We may examine this formula in the case of a polarised pencil passing through a rhomboid of calcarious spar ; and making i the angle which the plane of polarisation of the ordinary image, that is, the principal section of the crystal^ forms with the primitive plane, the angle formed with the plane of polarization of the extraordinary image will be 90° — i; so that since cos'e represents the intensity of the ordinary image, that of the extraordinary image will be expressed by cos ^ (90° — z), or by sin ^i. When i =. 0, sin*t = 0; that is to say, when the principal section coin- cides with the primitive plane, the extraordinary image vanishes, and all the light passes to the ordinary image, because, in this case, cos*i= 1. When z == 45°, sinV and cos ^i become equal each to | ; and the two images are of equal intensity: lastly, when z = 90°, sin^'z— 1, and cos ^2 = 0, >yhich implies that the ordinary image vanishes, and all the Astronomical and Nautical Collections^ 111 light passes to the extraordinary image; and the same eifects are repeated in the other quadrants. It is obvious that these consequences of the formula agree with the observa- tions. In order that it should be considered as fully demon- strated, it would be necessary that it should be directly verified with intermediate values of t : but it has been sub- jected, in such cases, to several indirect criterions, which, without being perfectly decisive, very greatly increase the probability of its accuracy ; besides that we are encouraged by analogy and by mechanical considerations to conclude that it is rigorously correct. In examining the fundamental principles of the theory of undulation, we have found that the intensity of the light must be supposed proportional to the living force or energy of each undulation, or simply, for the same medium, to the sum of the squares of the forces of the different points of the undulation, and must consequently be proportional to the square of the common coefficient of these velocities : conse- quently if cos H is the intensity of the light of the ordinary image, cos i is the common coefficient of the velocities of oscillation in this image, and represents their magnitude ; and in the same manner, sin^e being the intensity of the liglit of the extraordinary image, sin i represents the velocity of the oscillations in the system of undulations which has under- gone the extraordinary refraction. We see then that the decomposition of the velocities of oscillation of the primitive polarised pencil, which is resolved into two others at its entrance into the crystal, are proj^ortioned exactly in the same manner as if the oscillatory motions, instead of being in the direction of the rays, were in a transverse direction, and either parallel or perpendicular to the plane of polarisation ; for in this case the two velocities conceived to have been united, and to be separated, would be proportional to sin i and cos i, according to the principle of the composition and resolution of the small motions of a fluid, which must be con- formable to the laws of statics. The formula of Malus appears, therefore, to imply, that the oscillatory motions of the ethereal particles are performed in directions perpendi- cular to the rays : and this hypothesis is rendered still morq JULY— SEPT. 1828. N 178 Astronomical and Nautical Collections. probable, by other remarkable properties of polarised light which remain to be explained. Mr. Arago and myself, in studying the interference of polarised rays, discovered that they exert no influence on each other when their planes of polarisation are perpendicular to each other, that is to say, that in this case they produce no fringes, although all the conditions, which are commonly necessary for their appearance, are scrupulously fulfilled. I shall mention the three principal experiments which served to establish this fact ; beginning with that which was made by Mr. Arago. It consists in causing the two pencils, emitted by the same luminous point, and introduced through two parallel slits, to pass through two very thin piles of transparent plates, such as those of mica, or of blown glass, sufficiently inclined to polarise almost completely each of the two pencils, taking care that the two planes, in which they are inclined, should be perpendicular to each other : in this case no fringes are observable, whatever pains we may take to compensate the difference in the paths, by causing the inclination of one of the piles to vary very slowly ; although, when the planes of incidence of the piles are no longer per- pendicular to each other, we always succeed in this manner in obtaining the fringes ; and the same result is obtained with much thicker plates of glass, provided that proper care be taken to form and polish them very correctly ; and to vary their inclination very slowly, in order that the fringes may not pass unperceived. In proportion as the planes of the two piles are further removed from parallelism, the fringes are weakened, and they wholly disappear when they are at right angles, provided that the polarisation of the rays have been tolerably perfect. It follows, from this expe- riment, that the rays of light, polarised in the same plane, interfere with each other in the same manner as rays not modified ; but that this influence diminishes as the planes are separated, and disappears when they are at right angles. A similar conclusion may be inferred from the following experiment. We take a plate of sulfate of lime, which, though Dr. Brewster has shown that it has two axes, yet, when divided into plates parallel to their common plane, Astronomical and Nautical Collections. 1% affects the rays of light in the same manner as if it had one axis only in an intermediate direction ; or a plate of rock crystal parallel to the axis, and of very uniform thickness ; this plate we cut into two pieces, and place one of them oft each of the parallel slits. Supposing now the halves to be 60 placed, that the edges which were separated remain pa- rallel to each other, the axes will also be parallel ; and in this case we observe but one system of fringes in the middle of the enlightened space, as before the division of the plates. But if we turn one of the pieces in such a manner as to destroy the parallelism of the axes, we form two other groupes of fainter fringes, one on each side of the former group, and completely separated from them, in the white light, when the plates of either crystal are about the twenty- fifth of an inch in thickness : and it is to be remarked, that the number of breadths of the fringes comprehended between the middle of one of these groups and that of the central group is proportional to the thickness of the plates, for cry- stals of the same nature, or in which the double refraction is equally marked, as in rock crystal and the sulfate of lime. In proportion as the angle formed by the axes increases, the new groups of fringes become more and more distinct, and acquire their greatest brightness when the axes of the two plates are perpendicular to each other : in this case the central group, which had gradually become fainter, altogether dis- appears, and is succeeded by a uniform light ; so that we must conclude that the rays which produced it by their inter- ference, are no longer capable of acting on each other. It is easy to infer, from the situation of these fringes, that they were formed by the interference of the rays which had under- gone the same kind of refraction in the two plates, since, having passed through them with equal velocities, they must have arrived at the same instant at the middle of the en- lightened space, the plates being supposed to be of equal thickness, and to remain perpendicular to the light ; and these central fringes were consequently formed by the inter- ference of the ordinary rays of the first piece with the ordi- nary rays of the second ; and by that of the extraordinary rays of the first, with the extraordinary rays of the second. N3 180 Astronomical and Nautical Collections. The two lateral groups, on the contrary, depend on the interference of the rays which have undergone different refractions in the two pieces ; and the ordinary rays moving the most rapidly in both the crystals which have been men- tioned, the left hand group of fringes must be formed by the combination of the extraordinary rays of the left hand plate, with the ordinary rays of the right hand plate, and the re- verse for the right hand group. We have now to consider the direction of the polarisation of the pencils which interfere, in order to determine the effects of the polarisation on the interference. It is natural to suppose, that the polarisation must be, as in thicker cry- stals, in the direction of the principal section, and in a direc- tion perpendicular to it : but since this supposition is con- trary to an ingenious theory of one of our most celebrated natural philosophers, it is necessary to confirm it by an ex- periment ; which may be done by cutting one of the edges of the plates obliquely, and obtaining a prismatic sepa- ration of the rays, which may then be directly shewn to be polarised according to the supposition : and if this were not reckoned sufficient proof, we might obtain it from the con- sistency of the solution which it affords, with the first experi- ment of Mr. Arago. It follows of course, that when the axes are parallel, the rays of the same refraction are polarised by each in the same direction, and those of each refraction are capa- ble of interfering respectively in the middle. When the axes were at an angle of 45° the rays of contrary descriptions were capable of producing some effects on each other, as well as the rays of the same description : so that there were three groups of fringes. Lastly, when the axes are perpendicular to each other, the rays of the same refraction are polarised in directions perpendicular to each other, so that the central group, which was formed by them, disappears, while the or- dinary rays of the left hand plate are then polarised in the same direction with the extraordinary of the right hand, which causes the right hand group, produced by these rays, to attain its maximum of intensity : while the left hand group acquire the same magnitude from the opposite refractions. There is a third experiment, which still further confirmjj Astronomical and Nautical Collections. 181 the inferences, which have been drawn from the first. I took a rhomboid of calcarious spar, polished on two oppo- site faces, which were carefully made parallel, and sawed it perpendicularly to these two faces, so that I had two rhom- boids exactly equal in thickness, and in which the paths of the rays were consequently of equal lengths at equal incli- nations. I placed them one before the other, so that the rays which passed perpendicularly through the one passed in a similar manner through the other : the principal section of the one was also perpendicular to that of the other, so that there were only two pencils which pervaded them, the ordi- nary pencil of the first being extraordinarily refracted in the other, and the reverse. Now it resulted from this arrange- ment, that the differences of the paths depending on the dif- ferent velocities of the ordinary and extraordinary rays, were compensated in each of the pencils. The pencils crossed each other in a very small angle, so that the fringes which they would have formed must have had a much greater breadth than was sufficient for their being visible ; and yet, notwith- standing that all the conditions necessary for the production of fringes, in common cases, were strictly observed, I could never succeed in obtaining them. While I looked carefully for them, with a lens in my hand, I caused the direction of one of the rhomboids to vary slowly, moving it sometimes to the right, and sometimes to the left, in order to compensate for the effect of any difference in the thickness, if it existed : but although I repeated this trial a number of times, I still observed no fringes ; and indeed they were not to be ex- pected, considering the experiments which have been related, since the two pencils emerging from the rhomboids were po- larised at right angles. It was not for want of a correct adjustment that the ex- periment did not succeed ; since I easily obtained the fringes, if I employed light which had been polarised before its entrance into the rhomboids, when the polarisation is again changed after its emersion. It is therefore completely demonstrated, by the experiments which I have just related, that rays po- larised at right angles cannot exercise any sensible influence on each other ; or in other words, that their coiribination 182" Astronomical and Nautical Collections, always affords the same intensity of light, whatever may be the difference in the routes of the two systems of undulations which interfere. Another remarkable circumstance is this ; that when they have once been polarised in rectangular directions, it is no longer sufficient that they be brought back to a common plane of polarisation, in order to exhibit appearances of in- fluencing each other. In fact^ if in Mr. Arago's experi- ment, or in that which I have described after it, we cause the rays which have been transmitted by the slit, and which are polarised at right angles, to pass through a pile of inclined plates, we perceive no fringes, in whatever direction we turn the plane of incidence. In place of such a pile, we may em- ploy a rhomboid of calcarious spar : and if we incline its principal section in an angle of 45° to the planes of polarisa- tion of the incident pencils, so that it may divide the right angles v/hich they form into two equal parts, each image will contain the half of each pencil ; and these two halves, having the same polarisation in the same image, ought to produce fringes, if it were sufficient to restore the plane of polarisa- tion in order to renew the mutual influence of the pencils. But it is impossible to obtain fringes in this manner, except when the light has been polarised in some one plane, before it is divided into two pencils polarised at right angles. When, however, the light has undergone the preliminary polarisation, on the contrary, the interposition of the rhom- boid restores the fringes. The most advantageous direction, that can be given to the primitive plane of polarisation, is that which divides into two equal parts the angle of the orthogonal planes, in which the light is at last polarised, be- cause, in this case, the light is equally divided between them. We may suppose, to assist the imagination, that the plane of the primitive polarisation is horizontal, the planes of the two polarisations which follow being inclined to it in angles of 45°, the one upwards, the other downwards, so that they may be perpendicular to each other. We may obtain this orthogonal polarisation either by means of the two small piles employed in the experiment of Mr. Arago, or by two plates, with their axes in orthogonal directions, or with a single cry- Astronomical and Nautical Collections* 1§^ stalllzed plate : and this last case is the best fitted for om* purpose, the others affording only phenomena which are pre- cisely similar. In order to divide the light into two pencils which inter- sect each other in a small angle, and which are thus fitted to afford fringes, the apparatus of two mirrors is in general preferable to the screen with two slits, because it affords more brilliant fringes ; besides, it has here the advantage of giving to the pencils the previous polarisation required for the; experiment. It is sufficient for this purpose that the mirrors should be of unsilvered glass, and inclined about 35° to the incident j'ays: and care must be taken to blacken them on the back, in order to destroy the second reflexion. We place near them, in the path of the light, and perpendicularly to its direction, a plate of sulfate of lime, or of rock crystal, cut parallel to the axis, and a tenth or twentieth of an inch in thickness ; inclining the principal section in an angle of 45^ to the plane of primitive polarisation, which we have sup- posed to be horizontal. The apparatus being thus arranged, we shall only see a single group of fringes through the plates as before its interposition, and occupying the same situation. But if we put before the lens a pile of glass, inclined either to the horizontal or to the vertical direction, we shall dis- cover, on each side of the central group, another group of fringes, which will be so much the more remote from it as the crystallized plate is thicker. If we substitute for the pile of glass a rhomboid of c^lcarious spar, of which the principal section is in a horizontal or a vertical direction, we observe, in each of the two images that it produces, the two additional systems of fringes which had been before formed by the in- terposition of the pile ; and it is remarkable, that these two images are complementary to one another ; that is to say, that the dark stripes of the one correspond to the bright stripes of the other. We see in this experiment a new confirmation of the prin- ciples which are demonstrated by the foregoing. The rays, which have undergone the contrary refractions, cannot affect each other ; because, when they emerge from the same plate, in the case that we are considering at present, they 184 ^Astronomical and Nautical Collections, are polarised in orthogonal directions; and consequently the groups of fringes on the right and left cannot exist, un- less we restore their mutual influence by reducing them to a common plane of polarisation : and this is done by the inter- position of the pile of glass plates, or of the rhomboid. The fringes thus obtained are so much the more marked, as the two contrary pencils which produce them are more equal in brightness ; and it is for this reason that they are best dis- tinguished when the principal section of the rhomboid makes an angle of 45° with the axis of the plate. When this prin- cipal section is either parallel or perpendicular to that of the plate, the rays refracted ordinarily by the plate, pass intirely into one of the images, instead of being divided between the two ; and all the extraordinary rays pass into the other image : so that the rays of the separate descriptions do not interfere with each other ; and the additional groups disap- pear : each image presenting only those fringes which are derived from rays of the same kind, that is, those which form the middle group. These two groups of additional fringes exhibited by po- larised light, in the first position of the rhomboid, furnish one of the most accurate modes of measuring double refraction, and of studying its laws. In fact, their eccentric position depends on the difference of the paths of the ordinary and extraordinary rays which have passed through the plate, and we may judge of the number of undulations that the extra- ordinary rays of the pencil have been left behind the ordi- nary rays, by the number of breadths of fringes compre- hended between the middle of the right hand group and that of the middle group : and this difference in the paths is still better measured by the interval comprehended between the middle points of the lateral groups, which is twice their distance from the middle of the central groups. It is most convenient to employ white light for these experiments : first, because it is the brightest, and secondly, because it renders the middle point of each group more easily distinguishable. It is true, that we only measure in this manner the double re- fraction of the brightest rays, that is, the yellow ; but this is precisely the mean, double refraction, and besides, that of the Astronomical and Nautical Collections, 185 other rays differs in general very little from this. And if we compare the thickness of the plate with the difference of the paths thus formed, we may compute from it the difference of the velocities of the ordinary and extraordinary rays. With this apparatus, Mr. Arago and myself made an ex- periment on a plate of rock crystal parallel to the axis ; and the result of our measurements gave us the same difference in the velocities of the ordinary and extraordinary rays as Mr. BioT had found by direct observation of the diver- gence of their rays in prisms of the crystal. Mr. Biot's method is equally accurate with ours, when it is required to determine the refraction of crystals which have great powers of separation, such as carbonate of lime, rock crystal, and sulfate of lime : but the method furnished by diffraction is far preferable for substances in which the difference is less sensible : for if we take a pretty thick plate, we can determine the difference of the velocities of the two kinds of rays with a degree of accuracy almost unlimited ; and it is not even necessary that the plate should have any considerable thickness, in order that a very high degree of accuracy may be attained : for it is easy to perceive a differ- ence of one-fifth of an undulation, that is, of four millionths of an inch, in the lengths of the two paths. The same experi- ment might be applied equally well to the purpose of veri- fying, in the most delicate manner, the law of Huygens, as re- lating to rays passing very nearly in the direction of the axis. The agreement, thus obtained, between our results and those of Mr. Biot, is sufficient to show the multiplicity of relations which the principle of interference establishes be- tween those phenomena of optics, which appear at first sight to be the most diversified in their nature. We have supposed the rays of light to be polarised in the same manner in these crystalline plates as in the thickest crystals, that is to say, that the rays which are transmitted by the ordinary refraction are polarised in the principal section, and the others in a direction perpendicular to it. This hypothesis, deduced from the most direct analogy, ought not to be abandoned, unless it were found to be in positive contradiction with the phenomena j and, in following the 188 Astronomical and Nautical Collections consequences, to observe what pencils ought to influence each other, and to produce fringes, we have always seen the results of observation agree with it. Besides, the plates employed in our experiments, being always at least four hun- dredths of an inch in thickness, were capable of having their edges cut obliquely, and producing by these means the sepa- ration of the ordinary and extraordinary pencils, which are then found polarised in directions parallel and perpendicular to the principal section. It i^ not at all probable that this mode of polarisation should be determined by the very slight inclination of the two faces of the crystal, which divides the light into two distinct pencils when this angle is of only ten degrees : in short, a prism of glass of an equal angle gives but a slight degree of polarity to the light by the obliquity of its surfaces, which, even if it were more consi- derable, would only cause a polarisation perpendicular to the plane of incidence. Thus, if we consider the polarising action of the prism of crystal as generally composed of two parts, the one depending on the inclination of its surfaces, and the other on its double refraction, we can only attribute to the latter a polarisation of the two pencils in the directions which are parallel and perpendicular to the principal sec- tion, and we must conclude that they undergo the same kind of polarisation when the parallelism of the faces prevents us from distinguishing them, since this parallelism makes no change in the laws of the double refraction. These consequences, however conformable they appear to the rules of analogy, have, however, not been admitted by Mr. BioT, who supposes light to receive, in thin crystallized plates, and even in such as are a tenth of an inch in thick- ness, a form of polarisation wholly different from that which it exhibits when it emerges from a crystal thick enough to separate it into distinct pencils. The opinion of so respect- able a natural philosopher was of sufficient importance to induce me to establish, by some new experiments, the true direction of the polarisation of the ordinary and extraordi- nary rays in crystallized plates : but the results which I have obtained were always conformable to the general analogy of double refraction. Astronomical and Nautical Collections. 187 Having placed the two halves of a plate of sulfate of lime, about one twentieth of an inch in thickness, before two slits cut in a screen, and turning these plates in such a man- ner that their axes were perpendicular to each other, I examined, by means of a rhomboid of carbonate of lime, the direction of the polarisation of each of the two groups of fringes which they produced. We have seen that the right hand group results necessarily, according to the known laws of interference, from the combination of the extraordinary rays of the right hand plate with the ordinary rays of the left, since these latter move the more rapidly in the sulfate of lime : this group must therefore be polarised perpendicu- larly to the principal section of the right hand plate, since this is the direction of the polarisation both of the ordinary rays of the left, and of the extraordinary on the right, ac- cording to the actual arrangement of the plates : and since, besides, direct experiments on the interference of rays po- larised in any plane, show always that the fringes are polarised in the same plane. In the same manner, the group on the left, resulting from the interference of the ordinary rays on the right with the extraordinary rays on the left, will be polarised perpendicularly to the principal section of the plate on the left. Now these consequences of our hypo- thesis are perfectly conformable to experiment : for we find when the principal section of the rhomboid, placed before the lens, is parallel to the axis of the right hand plates, the ordinary image contains no other than the left hand fringes, and the extraordinary image the right hand fringes; and on the contrary, when the principal section of the rhomboid is parallel to the axis of the left hand plate, or perpendicular to that of the right hand plate, it is the left hand group that has disappeared from the ordinary image, and the left hand from the extraordinary. We see that the ordinary and extraordinary rays are here distinguished, not by their direction, as when the crystal is cut into the form of a prism, but by the difference of their effects of interference. Thus, for example, in the space occupied by the fringes of the right hand group, which re- sult from the interference of the extraordinary rays of th^ 188 Astronomical and Nautical Collections. right with the ordinary on the left, there arrive at the same time ordinary rays from the right hand and extraordinary from the left, which, being polarised in a common direction, neces- sarily influence each other, but produce no sensible fringes? on account of the too great difference of their routes, or on account of the too great distance of the point from the central stripe, which for these two pencils is on the left hand : for we have seen that, in white light, it is only possible to dis- tinguish a very limited number of fringes, beginning from the middle stripe, and that beyond the seventh or eighth order the combination of the two pencils produces uniform light only. The ordinary and extraordinary rays of each plate are always found together at the same point of the enlight- ened space ; but some of them form sensible fringes, by their interference with rays of a contrary description coming from the opposite plate ; while the others constitute a white light only ; and from this distinction we are able to examine them separately, and to determine the direction of their polarisation. When two pencils which interfere are polarised exactly in the same direction, the fringes which they form possess the same character: but when the directions of their polarisation form an acute angle with each other, the fainter fringes, which they now produce, appear to be polarised at once in both directions, since they disappear from the extraordinary image when the principal section of the rhomboid is turned either in the first or the second direction ; one of the pencils being excluded in either case, so that the interference can no longer take place, and the light must remain uniform. Having shown that these phenomena of interference con- firm the general hypothesis, it remains to be proved that they are inconsistent with the ingenious theory of moveable polarisation, the fundamental principles of which it is neces- sary to explain. Mr. BioT supposes, that when a polarised pencil passes through a doubly refracting crystal, of which the principal section is situated obliquely with respect to the primitive plane of polarisation, the axes of the luminous particles, which had been situated in this plane, undergo, at theirentrance into the crystal, certain oscillations, which carry them alter- Astronomical and Nautical Collections. 189 nately to the right and left of the principal section, sometimes arriving at the primitive plane, and sometimes at another plane situated at the same angular distance on the other side, or at the azimuth 2i, calling the angle formed by the two first planes i. For example, if the principal section makes an angle of 45°, with the primitive plane of polarisation, the axes of the particles vibrate through an arc of 90°, which is now 2t. Mr. Biot supposes that these oscillations are repeated a very great number of times before the particles attain a fixed polarisation, which arranges their axes, so as to make them either parallel or perpendicular to the principal sec- tion : and a thickness of some tenths of an inch, or perhaps of some inches, is required, according to this able experi- menter, in order that the moveable polarisation should become fixed in the sulfate of lime, at least while the paral- lelism of the two surfaces prevents the separation of the ordinary and extraordinary pencils, which is always accom- panied by the fixed polarisation. But when the faces are parallel, and the thickness of the plate does not exceed the limit, the particles of light which pass through it, instead of being polarised in the principal section, and in the direction perpendicular to it, are polarised either in the primitive plane, or at the azimuth 2z, accordingly as the last oscillation of their axes was directed towards the first or the second plane, and this whether it was finished or only begun at the time of their emersion; at least, according to Mr. Biot, they are affected by the rhomboid which is employed for analysing the emergent light, as if their last oscillation had been finished. The time occupied by one of these oscillations, or the thickness of the crystal in which each of them is per- formed, is supposed to be constant for particles of the same nature, but variable in the different kinds of light, in pro- portion to the length of the ** fits" [imagined by Newton.] Let us now examine the consequences of this, and consider the case of the two halves of a plate of sulfate of lime, about the tenth of an inch in diameter, placed before two mirrors of black glass in the path of the reflected rays. Let us sup- pose that the mirrors, disposed in such a manner as to pro- duce the fringes, are inclined in an angle of 35° to the rays which proceed from the luminous point, so that they may b^ 190 Astronomical and Nautical Collections, completely polarised by reflection before their introduction into the crystallized plates, as in the apparatus already described : and let us suppose that the axes of the two plates are perpendicular to each other, and each make an angle of 45° with the plane of reflection. According to the theory of moveable polarisation, all the emerging rays must b6 polarised in a direction parallel or perpendicular to this plane, which is that of the primitive polarisation : thus each of the two groups of fringes, which are observed to the right and left, results from the interference of the two pencils polarised both in this plane, or both in the direction per- pendicular to it : consequently, if the two groups of fringes could exhibit signs of polarisation, it could only be in one or the other of these orthogonal directions : now the experiment is as opposite as possible to this consequence, since it is pre- cisely when we place the principal section of the rhomboid in one or the other of these directions, that the two images of each group possess the same intensity : and in order that one of them may vanish, it is necessary, on the contrary, that the principal section of the rhomboid should make an angle of 45° with these directions, that is to say, that it should be parallel or perpendicular to the principal sections of the two plates. When it is parallel to the left hand plate, it is the left hand group that disappears from the ordinary image, and the reverse. It is obvious that the direction of the polarisation is the same as in the experiment last related, in which the incident light had not undergone any previous polarisation, before it passed through the crystallized plates. Thus, whether we employ direct or polarised light, the ordinary and extraordinary pencils into which it is divided in passing through a crystallized plate, are always polarised, the one in the plane of the principal section, and the other in a direction perpendicular to it. We have hitherto employed plates not less than a twentieth of an inch in thickness, and we have constantly found, in the ordinary and extraordinary rays, the same direction of pola- risation as they manifest when they are separated into distinct pencils. It was, however, interesting to ascertain also, by means of interferences, whether the same mode of polarisation was also to be found in much thinner plates, such as those Astronomical and Nautical Collections. 191 which give colours to polarised light, when it is analysed at its emersion, by means of a rhomboid of calcarlous spar : for it is this production of colours that led Mr. Biot to a con- trary supposition. For this purpose, I took a plate of sul- fate of lime, about one hundredth of an inch in thickness, which exhibited strong colours, and yet was in no danger of having the different groups confounded : and having divided it into two pieces, I placed them in the manner already described. The two groups of fringes, instead of being entirely separated, as they had been when the plates were three or four times as thick, were mixed a little in the inter- mediate space ; tut it was easy, nevertheless, to distinguish in each of them the stripes of the three first orders, and to ascertain that the right hand group, for example, was pola- rized perpendicularly to the axis of the right hand plate ; for when the principal section of the rhomboid was turned in this direction, it disappeared entirely from the extraordinary image ; and when, instead of the rhomboid, a pile of glass, sufficiently inclined in its direction, was placed before the lens, the left hand group only was discernible, and was in this case perfectly free from the niixture of the colours of the right hand group, exhibiting the usual appearance of a single group. And when the experiment was made with two me- tallic mirrors, the slight polarisation which they occasion in the reflected rays, being destroyed by a pile of three or four pieces of glass, properly inclined, before their passage through the plates, the same direction of the polarisation is still found for each of the groups of fringes. It is therefore fully proved, that in one of these cases, as well as in the other, the thin plates polarise the ordinary and extraordinary rays in directions parallel and perpendicular to their axes. Having shown that the hypothesis of moveable polarisation is contradicted by facts, whenever it is possible to distinguish the ordinary from the extraordinary rays, I shall now pro- ceed to a particular description of the phenomena of the colours of crystallized plates, which led Mr. Biot to this hypothesis, and I shall show that it is by no means neces- sary to their explanation. [To be continued in our next Number.] 192 Astronomical and Nautical Collections, ii. Principal Lunar Occultations of the fixed Stars in the months of November and December, 1828, and January, 1829, calculated for the Royal Observatory at Greenwich. By Thomas Henderson, Esq. Date. Names of Stars. Magni- tude. Immersion and Emersion. Mean Time. Apparent Difference of Declination. Point of Moon's Limb, H. M. S. ,^ . n Nov. 21. ^ Tauri 4.5 Imm. 12 30 55 15 41 N. 6R. Em. 12 43 1 14 56 N. 27 R. 26 A' Cancri 6.7 Imm. 11 1 41 5 4S. 150 L. Em. 12 8 2 3 S. 52 R. Dec. 21 u Geminorum 5.6 Imm. 9 1 20 4 16 N. 112 L. Em. 10 12 9 4 26 N. 42 R. 25 9r Leonis 4.5 Imm. 10 19 42 8 6 N. 96 L. Em. 11 3 56 13 14 N. 11 L. Jan. 8 9- Aquarii 4.5 Imm. 6 1 47 11 36 N. 17 L. Em. 6 59 1 16 N. 123 R. ») q Aquarii 6, Imm. 7 39 47 10 35 S. 94 L. Em. 8 7 52 16 16 S. 151 L. 18 X Geminorum 4.5 Imm. 8 50 21 10 41 S. 167 L. Em. 9 51 21 8 35 S. 104 R. The explanations of the colu mns are tl le same as in the preceding Numbers. An error of 11 seconds in tl moon and star will be sufficien the 21st of November, into an i le comput t to conve ippulse. ed difference of declination between the rt the predicted occultation of V^ Tauri on An occultation of o Piscium by calculation at 15^ 30" mea moon's southern limb. The Greenwich. may possi n time, th star will bly happen on the 18th of November ; for e star is only 27 seconds distant from the be occulted to places further north than [To be c ontinued.] 193 MISCELLANEOUS INTELLIGENCE. § I. Mechanical Science. 1. Tulley*s New Catadioptric Microscopes. — Mr. W. Tulley, stimu- lated by the example and success of Amici, has invented a reflecting microscope, the optical principle of which is, we believe, entirely iiew and original ; the objective part consists of an elliptic metal, and a perforated plane one of corresponding dimensions, forming an angle of forty-five degrees with it. A section of a cylinder is introduced into the hole of the plane metal, in such a way as to allow light to pass towards the elliptic metal, but to exclude it in every other direction, so that no false rays can enter. The manner in which the instrument operates is as follows : — The object to be viewed is placed nearly whole in the plane, through which its rays diverge towards the elliptic metal, from which they are reverberated to the plane metal, which reflects them at right angles to the eye-piece, by which the image they form is viewed in the usual way (the object of the section of the cylinder is to exclude false light). This instrument has its good and evil properties, like all others. It has been duly executed by Mr. Tulley, and may be considered in its optical principle and its performance, equal to that of Professor Amici, over which, indeed, it possesses the advantage of being capable of receiving an unlimited angle of aperture. The objection to it is that the diagonal metal does not permit the ap- proach of an object to the focus of the elliptic one, with the facility necessary for practical purposes. Only very small objects can be viewed, which must be mounted in a particular manner, having to be introduced as it were into the external part of the hole in the plane, where no latitude of motion can take place ; sliders, aquatic live boxes, &c. are wholly inadmissible : these defects, will we are afraid, confine this instrument to the cabinets of the curious. There is a great difficulty in executing the plane metal, for that part immediately about the hole must be perfect, and the sharp edges of the aperture are a great obstacle to correct execution (which, however, has been conquered by Mr. T.). There are impedi- ments also in the adjustment of the plane, which is apt to lose its figure, being made as thin as possible to admit the approach of the object to it. The other microscope forms its image by one reflection only. Opaque objects are mounted upon a small arm, and presented to the focus of an elliptic metal inserted at the end of a tube, at the other extremity of which the usual eye-glasses are placed, while the illumination is effected from an aperture in its side. Transparent objects are illuminated by means of light, furnished by a small plane metal placed diagonally behind them, being in fact exactly similar to that which is employed in the Amician JULY— SEPT. 1828. O 194 Miscellaneous Intelligence, microscope, to co-operate in forming the image, but which is here used only as an illuminator, being removed beyond the focus of the concave metal. Any Amician instrument may, of course, be easily modified into this form, for it will be merely necessary to draw its plane metal further back, and to perforate a fresh hole in the side of the tube to admit the light, with some additional contrivance to present the object in its proper place. This reflector, considered only with reference to its optical principle and performance, is at once the most simple and the most perfect of the whole family of compound microscopes, but has nearly the same inconveniences as the other, relative to the application of objects. To those who regard not the difficulty at which they procure perfect vision, this instrument must be highly valuable, and probably will long retain a place among microscopes as a verificaior or proof engiscope ; for there can be no doubt that the vision it affords is of the purest and most un- adulterated nature. 2. Carpenter*s Aplanatic Solar Microscope. — This is the first solar instrument which has ever possessed achromatic object-glasses regularly worked to correct diverging rays. The experiment of converting telescopic object-glasses of short foci to the purpose of forming an image for the solar microscope has been oflen made, but of course without any good effect ; it is as rational to expect that such glasses should answer both for divergent and parallel light, as that the same medicine should cure a diabetes and a dropsy. The pictures of microscopic objects given by the present instrument are totally freed both from chromatic and spherical aberra- tion, and in consequence of which the coloured fringe which forms the outline of all objects shown with common object glasses is re- moved, together with that nebulous indistinctness which causes the image to appear a mere shadow when inspected closely, and, there- fore, fit to be viewed only from afar. The observer may boldly proceed up to the very screen on which the picture is formed by the achromatic glasses, and will find that the image instead of losing by this close scrutiny developes those minute details which were invisible at a distance. But it is chiefly when opaque objects are viewed that the incontestable superiority of the achromatic shines forth in all its splendour (especially if con- trasted with the effects of common glasses, which, it is well known, give an image of radiant bodies, which is a mere jumble of aberra- tion of both kinds, not fit for public exhibition.) Those who fancy that aplanatic glasses are no better adapted to the nature of a solar microscope than to that of a camera-obscura, would do well to examine Mr. C.'s instrument ; in fact the public voice has already decided the question, The frame of this instrument is on a gigantic scale, the illuminat- ing lens being a foot in diameter, with everything else in proportion. Mechanical Science. 195 The immense body of light condensed together by it gives a won- derful richness and vivacity of colouring to the image wliich, com- bined with its sharply-defined outline and vast dilatation, distends the faculties with surprise and pleasure, frequently surpassing the most lively anticipation. Upon the whole there would be nothing to wish for or to find fault with about Mr. C.'s instrument if it possessed aplanatic object- glasses of sufficiently short foci to developethe tissue of animalcules and other regular microscopic objects. Nothing certainly can exceed the perfection of its combined double treble achromatic, the power of which is also admirably adapted for exhibiting large popular objects, but far too low to show those curious and difficult minutia which gratify a connoisseur. Such an objective as that famous deep sextuple one lately worked by Mr. W. TuUey, which demonstrates the most difficult test objects with such incomparable facility, would complete the effectiveness of this really respectable and scientific engine of public instruction and amusement. This deficiency is shortly to be supplied. 3. Improvement in the Barometer. — An improvement has been made in the barometer of Gay-Lussac by M. Bunten, which has been submitted to, and received the approbation of, the Academy of Sciences at Paris. Its object is to prevent the introduction of bubbles of air, which almost inevitably takes place when the barometer is carried either on foot or horseback, or in a carriage, in a horizontal posi- tion. It consists in expanding the glass in one part of the wide tube, so as to form it into a chamber, from the centre of which a capillary tube of a certain length descends perpendicularly, by which the mercury must necessarily pass, either when rising or falling. If a bubble of air enters, it necessarily moves up by the surface of the large tube, and is stopped at the top of the chamber, producing no error in the observation made whilst it is there. When the barometer is inverted the bubble escapes of itself. This invention, the reporters observe, does away with the only inconvenience attend- ing the use of Gay-Lussac's barometers, without adding anything to their fragility. — Revue Ency. xxxviii. 536. 4. Effect of the Moon upon Barometric Pressure. — M. Flauger- gues has added his efforts to those of the persons who have endea- voured to ascertain the effect of the moon's attraction upon the atmosphere of our globe, endeavouring to elucidate the subject by a very close and continued series of barometrical observations made daily at mid-day since 1808. The column of mercury in the baro- meter was 2.46 lines in diameter, and in the cistern 37.89 lines in diameter. The height was marked off" to the -j^^th of a line, and corrections made for capillarity, variations of the external level, temperature of the mercury both in the tube and in the cistern. The following is the table of the mean height of the mercury drawn 2 1&6 Miscellaneous TnteUigence, up from daily observations from 19th October 1808 to 18th October 1827, a period of nineteen years. The observations were made in the observatory at Viviers, 2^ 20' 55. "5 loncritude east of Paris, and 44° 29' I" north latitude. The basin of the barometer was 56.78 metres (186.3 feet) above the level of the Mediterranean. Mid-day was chosen for the time of observation, because the height of the barometer is not sensibly affected at that time by the sun. T ... Number of Mean heie-ht in Lunar positions. Observations. millimeters. General mean height 6915 755.44 New moon or conjunction 234 755.39 First octant 234 755.37 First quadrature 234 . 755.37 Second octant 235 754.65 Full moon or opposition 234 755.23 Third octant 234 755.70 Second quadrature 234 756.32 Fourth octant 235 755.48 Northern lunistice 258 755.73 Southern lunistice 258 755.42 Lunar Perigee 252.; 754.72 Lunar Apogee 252 755.82 The conclusions drawn by M. Flaugergues are — 1. That the ba- rometer rises from the second octant when it is lowest, to the se- cond quadrature when it is highest, and then again descends to the first point: the total variation is 1.67 miUimeters (.0657 of an inch). Thus in a lunar day, the barometer is lowest when the moon is 135° from the meridian towards the east; i. e., 9 hours 18j minutes of mean time before its passage across the meridian, or 6 hours 12j minutes after its passage. 2, The action of the moon is stronger when its declination is southern than when it is .northern, contrary to the theory of Laplace. 3. The difference between the actions of the moon at the apogee and perigee, is 1.1 millimeter of the latter greater than the former. The author finally concludes that the number of rainy days is greater when the barometric pressure is diminished than when it is augmented. — Bib. Univ.t Dec. 1827. 5. — On the Arravgeinent of JVater Pipes in Streets. — The effect of temperature upon iron pipes, used for the conveyance of water, and also some other circumstances have been investigated by M. Girard: he has arrived at the following conclusions. 1. According to the effect produced by change of season and temperature upon pipes of this metal placed in subterraneous galleries, they altered in length for each centesimal degree (1.8 degrees of Fahr.), 0.0000985, a quantity about -^ less than it would have been if they had not been confined on their supports by friction. 2. Although this effect is less when the pipes are put in the ground, it is still sufficient to occasion rupture, leakages, and other unpleasant accidents. 3. If the Mechanical Science, 107 joints are not made by bolts, but one end of a pipe is inserted into the mouth of the next pipe, then the space for the interposed sub- stance should be as small as possible, and the substance one which swells when in contact with water. 4. The lenj^th of the joints should be considerable, both to prevent the escape of water and the flexure of the system of tubes. 5. To ensure tightness, the stuffing* should be confined between a ring fixed to the end of the pipe, and a move- able ring sliding on the tubes. 6. That this precaution may be dispensed with by laying the pipes down in the coldest part of the season. 7. That pipes put into the ground should be supported at intervals by firm props of masonry, to prevent those inflexions which otherwise occur, and form ruptures. 8. That in large towns it is advantageous to place these pipes in subterraneous galleries, either such as are made on purpose, or else in the sewers. 9. That galleries have been tried advantageously for 20 years, and therefore should be resorted to, that those derangements of the pavement and inundations from broken pipes which are consequent upon the ordinary mode of proceeding, may, from henceforth, be avoided. — Globe, April 16, 1828. 6. — New Razor Straps. — A new kind of razor strap, invented by M. Ferrot, has received the name of euthegone. From the flexibility of leather, a round edge is given to the blade, for which reason paper is used in the new strap. Two kinds of very fine paper have been manufactured purposely, with fine and homogeneous pulp, mixed in the one case with fine emery, and in the other with very fine rouge. These papers are then steeped in melted tallow, after- wards pressed to give them a smooth surface, and then cut into bands, and mounted on pieces of wood properly shaped. Each strap has therefore two faces, one gray, on which the razor may be rendered very sharp, and the other red, which, polishing the edge, renders it extremely smooth. The razor must be laid very flat upon these straps — they improve by a few days use. When ineffectual from age, the surface should be rubbed with a very smooth piece of pumice, or with a little pumice powder on marble or ground glass ; being then wiped with a piece of cloth, they are brought to their first state. — Bull. Soc. Encouragement. 7.— On the Fusion of Tallow.— The Council of Health at Nantes has been engaged in an investigation of the best means of fusing tallow, so as to avoid the injury and annoyance which arises from an abundant liberation of vapours, when the ordinary method is used. Much pains has been taken in acquiring all the information possible, and numerous experiments have been made both on a large and small scale. The best process which the Council has instituted appears to consist in using, according to M. D'Arcet*s suggestion, a certain proportion of sulphuric acid, and operating in close vessels. By the use of the acid, the fumes always evolved are very much altered and ameliorated in quality, at the same time 198 Miscellaneous Intelliyenee, that the fused tallow is improved in quality and increased in quan- tity, the fusion very much quickened, and the use of a press dis- pensed with. By the use of close vessels, the fumes evolved can be either conducted to a fire-place to be burnt ; or, if that may be thoupjht dangerous, in consequence of the occasional boiling over of the melting tallow, can be conducted into a condensing apparatus^ which is found readily to condense them. M. D'Arcet uses 100 parts of crude tallow in small pieces, 50 parts of water, and 1 part of sulphuric acid, sp. gr. 1.848. In some small experiments a digester was used, having a pierced copper plate near the bottom to avoid the necessity of stirring ; 1500 (31b. 5oz.) parts of crude tallow, 750 of water, and 124 of oil of vitriol were used, and the fumes conveyed by a pipe into afire-place ; half an hour's ebullition completed the fusion. The infusible matter when pressed in a cloth, weighed only 96 parts, and was slightly acid. The tallow was white, hard, and sonorous, and not acid. Without the acid, the same effect was not produced in an hour. A tallow manufacturer then tried the experiment with 2 cwt. of tallow, using the acid, but operating in open vessels ; 92 per cent, of fused tallow was obtained, and 8 of loss occurred : in the ordinary way, 15 per cent, of loss occurred. In a second large experiment with acid, only 5 of loss occurred. The residue does not require the use of a press, but cannot be made into cakes for cattle, unless pre- viously freed from acid by washing. Experiments made on the condensation of the vapour was found to succeed very well, and thus all fear of injury from fire is avoided. The Council propose conducting the vapours into the drains of the works and so condensing them there ; no annoyance being appre- hended from the occasional return of the vapours into the building, as that effect can be counteracted by the use of stink traps. — Ann. de V Industrie, i. 295. 8. Method of hardening Plaster Casts and Alabaster. — The fol- lowing process is described by M. Tissot who has patented it in France. The piece of plaster or alabaster after being shaped, is put for 24 hours into a furnace. If the piece is only 1 8 lines thick, 3 hours in the furnace, heated up to the temperature required for baking bread, is sufficient ; if thicker, it is left in for a propor- tionably longer time. At the end of the time, it is withdrawn with caution and cooled, after which it is put for 30 seconds into river water, withdrawn for a few seconds, and then again immersed for a minute or two, according to its thickness. The piece is then exposed to the air, and at the end of three or four days, has acquired the hardness and density of marble. It may then be polished. — Bull, Univ. E. x. 26. 9. Injurious Co/owrs.— The Government of Lombardy has issued /• '(f^emical Science, ^ law, which, under penalty of confiscation, forbids the use of any venomous substance, such as arsenic, zinc, lead, and other mineral colours in the printing or dying of fabrics which are intended for clothing, or may come in contact with the human body. Many cutaneous affections, it is said, of which the cause has hitherto been unknown, are occasioned by the absorption of deleterious dying substances. — Nouveau Journal de Paris, 1828, p. 2. 10. Method of preventing Milk from turning sour. — Put a spoon- ful of wild horse-radish into a dish of milk ; the milk may then be preserved sweet, either in the open air or in a cellar for several days, whilst such as has not been so guarded, will become sour. 1 1 . Infernal change in the Position of Particles in Solids. — If a cer- tain quantity of the prismatic crystals of sulphate of nickel be enclosed in a bottle and then exposed to the heat of the sun, it frequently happens that though their external form is preserved, so that they may be measured, yet if broken they are found formed of a multitude of octoedral crystals with square bases. This change requires two or three days. These crystals by analysis appeared to contain 2.93 parts per cent, less of water, than the prismatic salt containing 7 proportionals. This is another striking instance of the internal motions of the particles of solid bodies. — Mitscherlich, Ann. de Chimie, xxxviii. 65. § II. Chemical Science. 1 . Conducting Power of Metals for Electricity. — The following are the results of M. Pouellet's researches on this subject, and are highly interesting, especially as regards the effect of alloys on the metals ; for even small quantities of foreign substances exert great influence on the conducting power. The purity of the silver is ex- pressed by the proportion of pure silver per cent, present in the alloy ; the column of figures represents the conducting power : — Silver of 98.6 ... 860 Red copper . . 224 Red copper ... 738 Brass. ... 194 Silver of 94.8 . . 656 Iron .... 121 Fine gold .... 623 Gold of 18 car. fine 109 Silver of 80 . , . 569 Platina ... 100 M. Pouellet finds, 1. That the conducting power is very exactly proportional to the section of the wires from the smallest diameter to that of three lines : 2. That it is in the inverse ratio, not of the length of the wire, but of the length increased by a constant quan- tity X. This quantity X, unchangeable for various lengths of the same wire, changes with the nature of the metal, and for each metal is in the inverse ratio of the section of the wire. M. Pouellet therefore believes that the conductibility is truly in the inverse ratio of the length of the wires, provided that the resistance opposed 1^00 Miscellaneous Intelligence. to the electricity in traversini^ the fluid in the cells of the pile and the different conductors which carry it to the experimental wire could be taken into account. — Bull. Univ. A. x. 59. 2. Conducting Power of different Fluids for Voltaic Electricity. — The following table is drawn up from the experiments of M. Foerstemann. The first column of fijrures indicates the specific gravity ; the second, the quantity of electricity conducted by the different substances in equal times; and the third, the time required for the conduction of equal quantities of electricity. Muriatic acid . 1.126 2.464 0.410 Acetic acid 1.024 2.398 0.423 Nitric acid 1.236 2.283 0.438 Ammonia 0.936 2.177 0.459 Sol. muriate of ammonia 1.064 1.972 0.509 Sulphuric acid 1.848 1.737 0.575 Sol. potash 1.172 1.709 0.585 Sol. common salt . 1.166 1.672 0.598 Sol. acetate of lead 1.132 1.560 0.632 Distilled water 1.000 1.000 1.000 Kastner's Archiv. iv. 82. B71II. Univ. A. x. 49, 3. Influence over the electric Powers of Metals. — In addition to the cases which have been pointed out by Avogadro, Marianini, De la Rive, and others, of a change produced in the electric powers of metals by various circumstances, the following striking one by Van Beek may be quoted. A plate of copper and a plate of iron con- nected by a platina wire were immersed separately in two vessels containing sea water, the portions of fluid being communicated by moistened cotton. Things were left in this state for forty-seven days, during which time of course the copper underwent no change ; after that period, the platina wire was cut, and it was then expected that the copper would be corroded, as will happen to a plate of copper put in the ordinary manner into sea water for a single day only. This effect however did not take place ; the copper remained bright, and the liquid clear, against all expectation, even though the cotton also was removed, and continued so after twenty days. This effect was not because the water had lost its power, for a portion of it, in w^hicli a, piece of ordinary copper had been immersed, caused corrosion in a single day ; and the copper itself being put into an- other portion of sea water, was instantly attacked by it. Hence it appears that the preservation of the copper for so long a time without action on the sea water must have been due to the mutual condition of the metal and solution, induced under the previous cir- cumstances of an existing electric current, and not altogether to a change cither in the one or the other. — Bib. Univ.., Mars, 1828. 4. Onihe secondary Piles of Rilier. — A long experimental memoir Chemical Science, 201 by M. Marianini on this subject is terminated by the following conclusions, which give the result of his investigations. 1. The electro-motive power in Ritter's secondary piles is not ])roduced by the difficulty which they oppose to the passage of the electricity ; since they acquire a polarity contrary to that of the voltaic piles with which they have been put in communication ; because the more rapid is the current the more readily do they arrive at a given state of tension, and also because in varying the nature of the plates the piles also acquire more or less readily a certain electro-motive power. 2. The developement of piles of the second kind in Ritter's columns have little or no influence on their activity, for on turning and changing the humid layers which would make them, the polarity of the whole is not changed. 3. The polarity of these secondary piles arises solely from the alterations produced by the electric cur- rent on the metallic surfaces in contact with the humid conductors ; for the plates being washed and dried still preserve their power of putting electricity in circulation if moistened pieces of cloth be put between them. The fact otfers a ready explanation of all the phe- nomena produced by these piles. — Aim. de Chimie, xxxviii. 40. 5. Comparison of the Tourmaline and had electro- conductors. — M. Becquerel has been engaged in examining the effect of heat upon bad conductors of electricity, and comparing them with the effects of heat upon the tourmaline, for the purpose of elucidating the electric states of the latter body, and of bodies in general. Heat which diminishes the conducting power of metals, increases that of glass, gum-lac, and bad conductors of electricity. The eflects which are produced when the temperature of glass is diminished, were those first examined. A small glass tube, .04 of an inch in dia- meter and between three and four inches in length was suspended to a fibre of silk and hung in a glass cylinder, the bottom of which was closed by a metallic plate : by heating the plate the temperature of the tube could be varied, and the effects observed. When the tube is dry and at common temperatures, it is powerfully attracted by an excited stick of gum-lac held near it ; but leaving the tube exposed to air, it soon becomes damp, and the attraction ceases. If again heated to 68° or 77° Fahr. nothing happens ; for the heat is not suffi- cient to dissipate the moisture on the surface ; but then, on remov- ing the lamp and allowing the temperature to fall, peculiar effects are noticed ; for the tube is immediately attracted, and continues to be so as long as the cooling proceeds. Again, raising the tempe- rature to 77°, the tube is not only attracted, but acquires two poles, which disappear on the removal of the electrified gum-lac; whilst on the contrary, when they are produced immediately on the re- moval of the lamp, they continue during the whole time of cooling. "When the temperature is raised to 212°, polarity is not occasioned in the glass tube under the influence of the excited electric until the moment when the thermometer begins to fall. When raised to 202 Miscellaneous Intelligence, 802°, polarity is not manifested until the temperature has fallen 2 or 3 degrees. In all these cases, it remains to the end of the cooling ; but if at any time the temperature of the air about the glass tube is raised 2 or 3 degrees, polarity disappears. These effects are analogous to those produced by the tourmaline under the same circumstances of heat, except that in the glass they are determined by the excited electric, and in the tourmaline by the peculiarities of crystallization. A small cylinder of gum-lac used in place of the glass tube was rapidly attracted by the excited electric at the moment of cooling from 68° or 77° ; but the polar state was very difficult to produce, and continued for a very short time. In these experiments the excited electric should have a nearly constant state ; one of the poles of a dry pile answers the purpose very well. M. Becquerel considers the theory of M. Ampere as accounting for some of these effects very well, but not for the permanency of the poles during cooling. The theory supposes atoms to have an electricity which is proper to them ; which, acting as neighbouring bodies, decomposes their natural electricity or electricities, attracting that of a different name, and repelling that of the same name, as in the Leyden bottle ; then these atoms become surrounded by an electric atmosphere, which partly hides the electricity proper to each, &c. M. Becquerel finds that the electric effects of tourmalines vary with their length, and he concludes, doubtless, with their breadth ; so that the intensity of the electricity developed may well be con- sidered as a function of these two quantities. Small tourmalines become more highly and readily electric than large ones. Large tourmalines which could not be electrized by heat alone, when broken gave fragments readily rendered electric. Admitting that this law is applicable, however much the size is reduced, it results that the integral molecule, should acquire an intense electric polarity for very feeble variations of temperature. Some facts induce M. Becquerel to suppose that the colouring matter of tourmalines may modify their electric properties. — Ajin. de Chimie, xxxvii. 369. 6. Electro-magnetic Current from heated Fluids. — M. Nobili connects the two ends of his galvanometer wire with the saline solution in two cups, and then these cups with two others contain- ing more of the same solution, by bundles of moistened cotton. Two small cylinders of clay are then made, and, when necessary, connected with the cups by moistened cotton, so as to constitute the ends of the arrangement. When one of these cylinders is dried, then strongly heated, and suddenly thrust two or three inches deep into the other soft and moist cylinder, the needle of the galvano- meter deviates as much as 80° from its natural position. This Chemical Science, 203- experiment is considered as bearing upon the theory of the globe, or at least upon that theory which supposes a central fire, since, by contact with the cold, damp superficial parts, the fire may be the active agent in producing magnetic currents. — Bib. Univ., 1828. 7. Purity of Metals tested by the Galvanometer. — Mr. (Ersted proposes the galvanometer as an indicator of the comparative oxidability of metals, and ako of their comparative purity. The metals in contact with the ends of the galvanometer wire are to be brought together with a portion of some proper fluid between them, and the relation of the two used, one to the other, will be indi- cated of course by the way in which the needle moves, and the extent of the motion. The needle is to be governed not by the magnetism of the earth merely, but by two magnets placed at a proper distance. The quantity of copper in an alloy of that metal with silver, may in this way be instantly ascertained. A series of metallic plates are to be prepared, from the purest silver down to mere copper, and of known composition ; then the piece of silver to be tried is to be applied to one or another of these, and both to the galvano- meter, until that plate is found which has the same electro-motive power with the piece of metal : they will then both have the same composition. Muriatic acid slightly diluted is the fluid to be used : it may be placed between the two metals by a piece of linen or well-washed amadou. The surfaces of the two pieces of metal for contact with the acid should be very clean, and exactly of the same size. — Jahrb. der Chemie, 1828. 8. Construction of Magnetic Needles. — According to M. de Legey, steel for magnetic needles should not be selected from amongst springs, for such steel is formed of fibres more or less hard, which, by the action of the hammer, has had different directions and une- qual hardness given to them. M. Legey prefers German laminated steel plate, from which he cuts a strip in the direction of the length, and then draws it out, so as to close the pores, till it is very brittle. From this plate he cuts the lozenge intended for the needle. All the operations should tend to lengthen the fibres in parallel direc- tions. The steel is then to be hardened, after which it is to be moderately tempered, then polished on the wheel, and finally magr netized to saturation. Before magnetizing the needle, it is examined, and usually found to have two poles. Whatever may have caused them, M. Legey regards the needle as more apt to receive magnetism, according to the position of these poles, than in any other direction, and there- fore endeavours to preserve them in every operation to which the needle is subjected; thus, in the polishing it should always be done in the direction of the length of the needles, and the southern pole should be held opposite to the course of the wheel ; a pro- ^04 Miscellaneous Intelligence. cceding' which it is affirmed preserves the position of the poles. When the needle is magnetized, the same attention to its previous state is to be given. — Bvll. de la Sec. Encourage^ 1827, p. 249. 9. Alteration of Brass Wire in the Air. — M. Cagniard de la Tour stated to the Academy of Sciences, that when long brass wires were stretched for some days in the open air, especially in wet weather, they became so brittle as to break with great facility v/hen bent to a moderately acute angle. 10. New Solar Phosphori, by M. Osann. — The solar phos- phori, prepared in the following manner, are described as being far more powerful in their effects than those previously known: — 1. Oyster-shells are to be calcined ; the whitest and most porous are to be selected, to be cleansed from all impurities, and then packed into a crucible in the following manner. The bottom of the crucible is to be covered with a thin layer of finely pulverized sulphuret of antimony, then an oyster-shell is to be put in, this is to be covered with more sulphuret, after which, a second shell is to be packed in, and so on, until the crucible is full. The pow- dered sulphuret should be spread uniformly by means of a fine sieve, and each layer of it should be about half a line in thickness. The crucible being closed, is then to be heated red hot for an hour. "When cold, the upper and lower shells, if spotted, are to be rejected, and the rest preserved. When exposed to sun hght, and then taken into a dark place, it shines brightly at every part, with a greenish-white light. A red heat applied for a long time causes the light to be white. 2. If the powder used be red sulphuret of arsenic (realgar), instead of antimony, the light of the phosphorus produced, after exposure to the sun's rays, is blue, like that of a sulphur flame. The phosphorescence is not so universal as with the preceding, but takes place only upon the white parts. Points occur here and there producing light of a fine reddish purple colour. If heated highly for a long time, the light produced by phosphorescence is then white. 3. Arseniate of baryta and gum, made into a paste, and heated to redness for half an hour, produces a yellowish-gray substance, which by phosphorescence yields a red light ; if heated more than half an hour, the light is yellow ; if for a long time, the light is white. Weaker phosphori are produced by using the following sub- stances with the oyster- shells : mosaic gold, light bluish; cinna- ber, light yellow ; white arsenic, light yellowish-blue ; blend and sulphur, light bluish. All the phosphori may be preserved in jars closed by bladder; even in the air they do not change rapidly : three weeks' exposure did not diminish their power. When the lime falls to powder, their effects are diminished. Those prepared Chemical Science. ^)5 with antimony anil realgar lose in the intensity of the colour when lonjr exposed to light, so that they should be preserved in black- ened bottles. Cold favours the absorption of light ; heat favours the dispersion ; boiUng water destroys the phosphorescence. Exposed to solar liglit for a minute, and then taken into a dark place, some Bo- lognian phosphorus shone for 4 minutes ; the third of those above, for 34 minutes; the first (with antimony) for 149 minutes; and at this period that prepared with realgar shone as brightly as it did one hour before. A red heat applied for several hours destroyed the power of the realgar preparation, very much weakened that with antimony, but did not affect that of the arsenic compound. The light of an electric spark passed one inch above these phos- phori makes them luminous. These phosphori shone even in the daylight, but their light then appears white. — Kastner's Arch. Bull. Univ. A. x. 50. 11. Preparation of Iodine by M. Souberan.>— The following is the process recommended by M. Souberan, by which he has obtained as much as -^^th part of iodine from mother liquors, that would yield none by the ordinary process. The mother liquors from the soda works, are to be diluted with 4 or 5 times their weight of water, and solution of sulphate of copper added, until precipita- tion ceases. The deposit will consist of iodide of copper and sul- phate of lime, and is to be separated. Large iron fihngs, or turn- ings, are then to be put into the liquid and agitated, until all smell of iodine has disappeared, by which process, the remaining portion of iodine will separate as an iodide of copper, mixed with metallic copper and the iron turnings, but easily separated by washing over. These two precipitates are then to be acted upon separately, in one of the following ways : 1. The iodide is to be mixed with two or three times its weight of peroxide of manganese, and a sufficient quantity of concentrated sulphuric acid, and then distilled, when all the iodine will rise with some aqueous vapour ; or 2. The mixture of iodide and oxide of manganese is to be heated in a retort to a high temperature, when pure iodine will come over ; the residue is pul- verulent, and can easily be extracted without breaking the vessel. — Ann. des MineSy N. S. iii. 102. 12. Action of Ammonia on heated Metals. — We gave an account in our last volume of M. Savart's experiments on this subject. M. Despretz claims the honour belonging to a prior discoverer on the following points. The diminution in density of copper, iron, and platina, after these metals have been employed in decomposing hydrogen gas. This fact he had published in his lectures, and in printed leaves, as early as December, 1827 ; and also the following, that during the decomposition of bi-carburetted hydrogen by heat, fusible white crystals were obt«ine