ཎ།འetup ft c (1999 557 MISCELLANEA. DEATH OF MR. MARSH, THE IN- In noticing the melancholy death of one of The value of Marsh's invention can hardly be fully appreciated by those who have not noticed the great services it has rendered to medical jurisprudence; but the rewards and distinctions bestowed by states seldom fall to the share of the labourers in the field of science, and yet such men have deserved more gratitude from their fellow-creatures than the bravest leader of an army, or the greatest hero that ever trod a quarter-deck. We extract the following paragraph on this subject from the Daily News, and earnestly hope the intention therein alluded to will be successfully carried out : that in a short time a sum will be raised sufficient to place the family above the imme. diate reach of want. Memorials have been forwarded to the various learned societies ciety of Arts (amongst others) having voted with which he was connected, the Royal SoMr. Marsh their silver medal for his test for the detecting of minute quantities of arsenic." GUN SAWDUST. MR. George Turner, a Leeds correspondent ON THE OLFACTORY POWERS OF "THE LATE MR. MARSH.-We have received the following suggestion for the benefit of the widow of this eminent but ill-paid chemist :-' Dr. May, of Rathfriland, suggests most respectfuly that a European sixpenny collection, in aid of the widow and family of the late chemist, Marsh, of arsenical test notoriety, should be at once set on foot. What would be better than every medical man, every chemist, every philanthropist forwarding his six postage stamps to a person that will be kind enough to receive the same, and a committee to consult what would be the best use to convert the sum into, for the aid of the widow and family? Who, after reading his various papers, would for a moment think of delaying a plan for the relief of all that was dear to departed worth and neglected talent?' Our correspondent will be glad to learn that a public subscrip-guided by the sense of smell, but that it is tion for the widow and family of this distinguished chemist has been originated at Woolwich, to increase the pittance of 201. voted by the Board of Ordnance to Mrs. Marsh. The Woolwich Consumers' Gas Company, of which Mr. Marsh was the superintendent, have granted the sum of 201, and Mr. Barlow has contributed 217., and it is expected BY N. MENDENHALL, M.D. IN reference to the sense by which the turkey-buzzard is guided in the search of its food, the experiments of Audubon, &c., would appear to be conclusive, inasmuch as they seem to prove that this bird is not led by the sense of sight only. I am not aware of the precise circumstances under which these experiments were conducted, yet, from facts which are known to myself, I cannot but infer that there must be some fallacy in the conclusions to which they lead. *American Medical Examiner. It is a very common practice in our part | doubt that the buzzards were attracted toof the Union, when any animal dies, to drag wards it by some other sense than that of it into some deep ravine in the neighbour- vision. hood, and there let it putrify and be devoured by the buzzards. These ravines or hollows are generally surrounded by bushes and trees of a very luxuriant growth, and notwithstanding the foliage is so thick that the rays of the sun cannot penetrate it, thus rerdering it in the highest degree improbable that anything under them could be distinguished by a bird in the air, yet we find the dead animal surrounded by buzzards-so far as I know, never before, but as soon as it begins to emit a perceptible odour. I could relate instances, too, of snakes and other small animals being killed and thrown out into a thicket of bushes and weeds so dense as to render any small object invisible at the distance of two or three feet; yet, whenever the smell of putridity became marked, these vultures were attracted to it in considerable numbers. What makes me more certain that they were led to it by the sense of smell only is the fact that, when they arrived within a short distance of the dead animal, they would alight and look about, and, not finding it, make shorter and shorter gyrations, until, seemingly, led on by a stronger and stronger scent, they reached the spot where they could gratify both their sight and taste. The arguments given above, however, are not absolutely conclusive, for it may be said that we are not positively certain that the buzzard was not here directed by the sense of sight, though this is in a very high degree improbable; and I will therefore give another instance on the authority of my roommate (E. B. Clark), which, it seems to me, added to the circumstances before mentioned, and others of a similar kind, ought to put this matter at rest. A number of swine, and among them a brood of little pigs, were in the habit of lying under an old barn. The barn had in a good measure lost its roof, but the floor of the part under which the swine slept was complete, and, moreover, piled up with boards, &c., so as to render it impossible that anything could be seen from above; and it was raised only about eighteen inches from the ground. One of the pigs died in this situation. Some short time after the workmen were engaged in hauling hay by this barn, and seeing a good many buzzards perched on a fence near it, which returned after being frightened away, and, on coming still nearer, perceiving the smell themselves, they were led to inquire into the source of it. After considerable search the dead pig was found far under the floor-so far, that in this instance there can be no Nor do I think that the observation of the English professor (Owen), alluded to by you, is of small weight in determining this question, not saying, by-the-way, that the question itself is of any great importance. I believe it is a principle very generally conceded, that the amount of sensibility in any part is in direct proportion to the amount of nervous matter distributed to that part, at least when the nerves are in a state of health. When, then, we consider the beautiful uniformity which prevails in the works of creation, and at the same time recollect that the Almighty architect formeth nothing in vain, we cannot but conclude that whatever the observation of Audubon, &c., may have shown in respect of the vision of the bird alluded to, its sense of smell is in a high degree acute, and that frequently it is guided by this alone. In relation to this subject may be cited the following remarks of the distinguished naturalist, Mr. Charles Darwin, M.A., F.R.S., in his "Journal of Researches into the Natural History and Geology of Coun tries Visited During the Voyage of H.M.S. Beagle Round the World":"When an animal is killed in the country (Chile), it is well known that the condors, like other carrion vultures, soon gained intelligence of it, and congregate in an inexplicable manner. In most cases it must not be overlooked that the birds have discovered their prey and have picked the skeleton clean before the flesh is in the least degree tainted. Remembering the experiments of M. Audubon on the contracted smelling powers of carrion-hawks, I tried, in an enclosed garden, the following experiment. The condors were tied, each by a rope, in a long row at the bottom of a wall; and having folded up a piece of meat in white paper, I walked backwards and forwards, carrying it in my hand at the distance of about three yards from them, but no notice whatever was taken. I then threw it on the ground, within one yard of an old male bird; he looked at it for a moment with attention, but then regarded it no more. With a stick I pushed it closer and closer, until at last he touched it with his beak: the paper was then instantly torn off with fury, and at the same moment every bird in the long row began struggling and flapping its wings. Under the same circumstances it would have been quite impossible to have deceived a dog. The evidence in favour of and against the acute smelling powers of carrion-vultures is singularly balanced. Professor Owen has demonstrated that the olfactory nerves of the turkey-buzzard (Cathartes aura) are highly developed, and, on the evening when Mr. Owen's paper was read at the Zoological Society, it was mentioned by a gentleman that he had seen the carrion-hawks in the West Indies, on two occasions, collect on the roof of a house where a corpse had become offensive from not having been buried in this case the intelligence could hardly have been acquired by sight. On the other hand, besides the experiments of Audubon and that one by myself, Mr. Bachman has tried in the United States many varied plans, showing that neither the turkey-buzzard (the species dissected by Professor Owen) nor the gallinazo find their food by smell. He covered portions of highly offensive offal with a thin canvas cloth, and strewed pieces of meat on it: these the carrion-vultures ate up, and then remained quietly standing, with their beaks within the eighth of an inch of the putrid mass, without discovering it. A small rent was made in the canvas, and the offal was immediately discovered; the canvas was replaced by a fresh piece, and meat again put on it, and was again devoured by the vultures without their discovering the hidden mass on which they were trampling. These facts are attested by the signatures of six gentlemen, besides that of Mr. Bachman." metric water. The remaining 46.60 grains were steeped in the mixed acids, washed, dried, and weighed, and found to have increased to 79 grains. The acids used were then examined, and it was found that the sulphuric acid was not at all diminished in quantity. By saturating the acids used with carbonate of soda, it was found that the cotton had taken up, or saturated, equal to 28 grains of soda, equivalent to 48 grains of dry nitric acid, the quantity which had combined with the 46.60 grains of cotton, forming the 79 grains of gun-cotton. The synthetical composition was then stated as46.60 parts cotton, less 15.60 water, taken away by the sulphuric and nitric acid, leaving cotton deprived of a portion of its constitution-water. oxygen equal to 48 parts dry nitrogen nitric acid. 35.55 12.45 79. ,, 19 or, 39.25 cotton, deprived of a portion of water. 45° oxygen. 15.75 nitrogen. 100 parts. From these experiments it was shown that it would require 114.75 parts of saltpetre, or 99.10 parts of nitrate of soda to form 100 parts of gun-cotton. CHEMICAL SOCIETY OF LONDON.* THE members of this society held their first meeting this session, at their rooms, John-riments related only to such gun-cotton as Mr. Teschemacher repeated that his expestreet, Adelphi, on Monday evening, the 2d instant. T. Graham, Esq., president, in the chair. An analysis of a Peruvian alloy was communicated by Mr. H. Howe, as illustrative of the state of the science of alloying, at the era to which it belonged. Mr. Teschemacher read a paper on guncotton. He states that he was induced to enter into the examination of the synthetical composition and formation of gun-cotton, with a view of obtaining some data by which an opinion could be formed how far the possible introduction of this substance, in the place of gunpowder, was likely to affect the production and consumption of saltpetre and and nitrate of soda. The gun-cotton examined was made by Mr. Taylor's process of mixed acids, and the experiments are, therefore, entirely confined to such gun-cotton. the same time, directed attention to the large was made by Mr. Taylor's process; but, at quantity of oxygen, viz., 45 parts in every 100, which must be derived from some ex traneous source, for combination with the cotton. In conclusion, he stated, that he nation of nitric acid in a similar manner with had made experiments also upon the combiother vegetable substances, such as flax, sawdust, &c.; he found that 50 grains of flax increased in weight to 72, but that the combustion of the substances was less perfect and less rapid than that of gun-cotton. Mr. Teschemacher could not give any idea of the relative strength of gunpowder and gun-cotton, as that was a subject which still remains to be examined. his opinion, that the degree of its exploMr. Taylor, on being called on, stated, as mercury and gunpowder. The suddenness sive force lay between those of fulminating of its explosion, he considered to be unfa Mr. Teschemacher dried fifty grains of South American cotton over a water-bath, and found it lost 3:40 grains, being hygro-vourable to its use as a projectile agent, com *Pharm. Times. pared with the slower action of gunpowder. Nitric acid was liable to be too rapidly dis 560 engaged, which was another disadvantage in its use, and it was observed, that when the cotton was pressed very tight the whole was not consumed. Mr. Warrington stated, that experiments had been made under the direction of the Hon. the East India Company at their depôt, which had shown considerable superiority of the cotton to gunpowder. Mr. Taylor invited the attention of the society to the remarkable fact, that, in explosion, the fibrous structure of the cotton remains unchanged, except as being rather harsher to the touch-a fact from the investigation of which new results might be expected. At the close of this discussion the meeting broke up. THE SOLUBILITY OF LEAD IN ALL PREVIOUS to the year 1757, A.D., lead-colic gas. THE EARL OF ROSSE'S TELE- WHEN Dr. (afterwards Sir William) Her- * Christison on Poisons. | received the highest power of which it was The The specu steam-engine of three-horse power. The polisher, moved by the same machinery, was connected to it by means of a ring of iron, which loosely surrounded it; and, instead of either the speculum or the polisher being stationary, both were contrived to move with a regulated speed. The material employed to wear down the surface was emery and water, a constant supply of which was kept between the grinder and speculum. This operation, which lasted six weeks, together with the casting and polishing, were all completed under the personal superintendence of Lord Rosse, and, by means of his untiring energy and skill, without the occurrence of any accident. The telescope, as now completed, consists of a tube of deal one inch thick, and hooped with iron, of the enormous length of fifty-six feet, including the speculum-box. On the inside, eight feet apart, are placed rings of iron of substantial thickness, for the purpose of strengthening the sides. The tube, seven feet in diameter, is fastened to stout masonwork in the ground, so contrived as to permit its free motion in every direction. Immediately in the meridional line, on either side of the telescope, are built two walls seventy-two feet long, forty-eight high on the outer side, and fiftysix on the inner, and twenty-four feet asunder, the tube being twelve feet distant from each wall; between these two walls is placed the machinery for adjusting the movements of the tube, which, when directed southerly, may be depressed till almost on a level with the horizon; but, when directed to the north, the arrangements preclude its motion further in that direction than in a position parallel to the earth's axis, that is to say, pointing to the pole of the heavens; its movements, laterally, are confined by the walls to a view comprising fifteen degrees. GUN-COTTON; ITS MANUFACTURE, ADVANTAGES AND DISADVANTAGES. THE following are the results of a series of experiments undertaken at Paris by order of Government, and communicated to the Academy of Sciences : With respect to the manufacture, it is necessary, in order to obtain a satisfactory result 1. To steep clean cotton in a mixture, composed of equal parts of nitric and sulphuric acids. 2. The length of time it is immersed appears to be of little moment; the best specimens were those which had been steeped for from 10 to 15 minutes. 3. We may employ a mixture, in which cotton has already been immersed, by reviving it, if necessary. 4. The cotton must not be above the level of the liquid. 5. It is necessary to dry the cotton slowly, and to avoid submitting it to a temperature exceeding 212° F., especially while still moist. 6. Its energy is somewhat increased by washing it in water saturated with saltpetre, but it is scarcely worth the extra expense. With respect to its use, gun-cotton possesses both advantages and disadvantages. The advantages are, cleanliness, rapid combustion, without a solid residue, the N.S., VOL. IV, absence of a bad smell, its lightness, being able to handle it without danger, of course at a distance from the fire, no possible dust or siftings, an incontestible power, which at present may be calculated at triple the force of an equal weight of gunpowder. Its disadvantages are, its volume, and, consequently, the difficulty of preparing it, and transporting it as a munition of war ; the production of a great quantity of watery vapours in the fire-arms, which is, perhaps, more troublesome while firing, than the incrustation left behind by common powder. As to the cost price, and the effects of this substance on fire-arms, these are subjects yet to be studied. What we have already acquired, is the knowledge of a new power, this is incontestible. This power exists, we can produce it; we have still to learn how to utilise it. There is no doubt we shall succeed in this attempt, and, at the same time, we shall be able to cause some of the disadvantages to vanish, which are at present visible. It is also to be presumed, that when we know better how to proceed, the cost of a substance, which can be manufactured in a loft, will not be alarmingly high. The experiments are being continued by the ordnance authorities. REMARKABLE PHENOMENON. THE Hon. Fox Strangways writes home :"In the immediate neighbourhood of Alexandersbad, near Wansiedel, a few miles south of the road from Bayreuth to Eger, in the Fichbelgebirge, is a mountain, called now the Louisenberg, formerly the Luchsberg, which is much visited by strangers on account of some of its natural curiosities. It appears not to cousist of any mass of rock, in situ, but to be an enormous heap of disconnected but rounded fragments of granite, thrown confusedly upon each other, and having arches, passages, and grottoes of various sizes, wherever the interstices have not been piled up with smaller pieces. The whole is overgrown with wood, so that, excepting where paths are made, it is difficult to penetrate. One of the caverns or chambers, formed by a single flat block of granite, resting horizontally as a roof on other masses, is nearly an exact circle of sixty feet English in diameter. Many that penetrate deeper into the rocks are mere crevices, but they present a remarkable phenomenon, which is not observable in the more open ones. This phenomenon consists of a pale but beautiful greenish yellow phosphorescent light, which, as the observer proceeds into 4 C |