THE BRITISH CRITIC, For JULY, 1806. Οὐκ ἔσι γῆρας τῶν σοφῶν, ἐν οἷς ὁ νῆς SOPHOCL The wife can ne'er grow old: th' immortal mind ART. 1. Philofophical Transactions of the Royal Society of 176 PP. FIFTEEN papers, from the 9th to the 28d inclufively, form the contents of this fecond part of the volume of the Philofophical Tranfactions, for the year 1805.-The fubjects of those papers are the following. IX. Abstract of Obfervations on a Diurnal Variation of the Barometer between the Tropics. By J. Horfburgh, Efq. This paper, on the movements of the barometer, is rendered peculiarly interefting from two circumftances; 1ft. It contains the refult of a barometrical journal, kept at fea, where the barometer has hardly ever been obferved with regularity and perfeverance. 2dly. It manifefts a very re. markable daily period in the rifing and falling of the mercury at fea, but not upon land. Mr. Horfburgh ufed two marine barometers of the best conftruction. They were fituated in the fhip's cabin, where A BRIT. CRIT, VOL, XXVIII, July, 1806, their their bafons flood at about thirteen feet above the level of the fea." "The hours," he fays, "at which the heights of the barometers and thermometers were taken; viz. noon, 4, 10, 12, 14, and 19 hours, were chofen, because at thefe times the mercary in the barometer had been perceived to be regularly ftationary between the tropics, by former obfervations made in India in 1800 and 1801. It was found that in fettled weather in the Indian feas, from 8 A. M. to noon, the mercury in the barometer was generally ftationary, and at the point of greatest elevation; after noon it began to fall, and continued falling till 4 in the afternoon, at which time it arrived at the lowest point of depreflion. From 4 to 5 P.M. the mercury rofe again, and continued rifing till about 9 or 10 P. M. at which time it had again acquired its greatest point of elevation, and continued ftationary nearly till midnight; after which it began to fall, till at 4 A. M. it was again as low as it had been at 4 afternoon preceding; but from this time it rofe till 7 or 8 o'clock, when it reached the highest point of elevation, and continued ftationary till noon.” "Thus was the mercury obferved to be fubject to a regular elevation and depreffion twice in every 24 hours in fettled weather; and the loweft ftation was obferved to be at about 4 o'clock in the morning and evening. I remarked that the mercury never remained long fixed at this low ftation, but had a regular tendency to rife from thence till towards & in the morning, and about 9 in the evening, and from thofe times continued ftationary till noon and midnight. "In unfettled blowing weather, efpecially at Bombay during the rains, thefe regular ebbings and flowing of the mercury could not be perceived; but a tendency to them was at fometimes obfervable when the weather was more fettled." P. 178. It appears likewife, from the obfervations mentioned in this paper, that the abovementioned periodical movements of the mercury in the barometer, are obfervable in the torrid zone, and as far as a few degrees beyond the tropics. Alfo that thofe periodical movements take place at fea, but not upon land, as Mr. H. particularly remarked in those parts of India and China where he had the opportunity of landing. X. Concerning the Differences in the Magnetic Needle, on Board the Inveftigator, arifing from an Alteration in the Direction of the Ship's Head. By Matthew Flinders, Efq. Commander of His Majefly's Ship Investigator. Captain Flinders, being employed in furveying along the fouth coaft of New Holland, obferved a very remarkable 3. irregularity irregularity in the magnetic needle; namely, that the direction of the needle was not the fame, when the fhip's head was turned one way, as when it was turned the contrary way. He took every precaution to remove whatever ap peared capable of influencing the motion of the needle; but all in vain; for the needle's direction continued to vary according as the fhip's direction was changed; and the difference, in fome cafes, amounted to about four degrees. The paper contains tables of his various obfervations; from which this author deduces the following inferences. ift. That there was a difference in the direction of the magnetic needle on board the Inveftigator, when the fhip's head pointed to the caft, and when it was directed weftward. 2d. That this difference was cafterly when the ship's head was weft, and wefterly when it was east. 3d. That when the fhip's head was north or fouth, the needle took the fame direction, or nearly fo, that it would on fhore; and fhowed a variation from the true meridian, which was nearly the medium between what it fhowed when eaft and when weft. 4th. That the error in variation was nearly proportionate to the number of points which the fhip's head was from the north or fouth." P. 191. This author then, with much propriety and diffidence, proposes the following conjectures in explanation of those phenomena. "ift. I fuppofe the attractive power of the different bodies in a fhip, which are capable of affecting the compafs, to be collected into fomething like a focal point or centre of gravity, and that this point is nearly in the centre of the fhip where the fhot are depofited, for here the greatest quantity of iron is collected together. 2d. I fuppofe this point to be ended with the fame kind of attraction as the pole of the hemifphere where the thip is; confequently, in New Holland, the fouth end of the needle would be attracted by it, and the north end repelled. 3d. That the attractive power of this point is fufficiently ftrong in a ship of war to interfere with the action of the magnetic poles upon a com pafs placed upon or in the binnacle." Ib. The latter part of the paper contains fome obfervations concerning the influence which Pier Head, upon the coast of New Holland, has upon the magnetic needle. XI. The Phyfiology of the Stapes, one of the Bones of the Organ of Hearing; deduced from a comparative View of its Structure, and Ufes, in different Animals. By Anthony Carlifle, Efq. F.R.S. The principal object of this paper is to give a more accurate defcription than had been before given, of that bone belonging to the organ of hearing, which has been denominated Rapes, Haffa, Rapha, or flapeda. Mr. C. juflly obferves, that, as the accurate anatomical defcriptions of the eye, which have been furnished by the ingenuity of profeffional perfons, have contributed to the advancement of optics; fo it may be reafonably expected, that a thorough examination of the ftructure of the organ of hearing will improve the fubject of acoustics for the benefit of the human fpecies. After a general, but concife, defcription of the principal parts belonging to the organ of hearing, this author gives a very particular and accurate defeription of the human tapes, with its various meafurements, and its ufual weight; and defcribes likewife the ftructure of the fame bone in various other animals. A plate, which accompanies this paper, exhibits various views of the huinan ftapes, and the ftapes of the hedge-hog, of the mole, of the mufk ox, of the elephant, of the tiger, of the dog, and of feveral other animals. Thefe defcriptions are accompanied with feveral judicious remarks, refpecting the peculiar difpofitions of the abovementioned animals, the different acuteness of their hearing, the different elements they live in, &c. "In man," Mr. C. fays, and the moft numerous orders of the mammalia, the figure of the tapes is an accommodation to that degree of lightnefs, which, throughout the feries of officles feems a requifite condition. It is alfo a conductor of vibrations in common with the other officles: but most efpecially it is defigned to prefs on the fluid contained in the labyrinth by that action which it receives from the ftapedeus mufcle, and the hingelike connection of the ftraight fide of its bafis with the feneftra veftibuli; the ultimate effect of which is an increase of the tenfion of the membrane clofing the fencstra cochleæ. "It does not appear that any degree of motion ever fubfifts between the officula auditus as wholes, which bears any relation to the peculiar vibrations of founds; but rather, that the dif ferent motions of thefe bones only affect the membrana tympani, and alter the degrees of contact in their articulations, fo as to influence the intenfity of violent impulfes; founds of lefs impetus, not requiring fuch modulation, are tranfmitted through the conducting feries by the vibrations of the integrant parts of thefe bones, unaccompanied by mufcular action. "This reafoning is fuggefted by the columelle in the aves and amphibia: and as many birds are known to imitate a variety of artificial founds with great accuracy, it may be inferred that they they hear fuch founds as acutely, and with the fame diftinctness as mankind. "It feems that all the muscles of the officula auditus are of the involuntary kind, and the peculiar ftimulus to their action is found. The chorda tympani, which fupplies them, is a gan. gliated nerve: if this fuppofition be true, then the mufcles should be confidered as all acting together, and it is well known that perfons who hear imperfectly are more fenfible to founds in a noily place, as if the mufcles were, by that means, awakened to action. "The office which the bafis of the ftapes holds, and which the ftapedeous mufcle is efpecially deftined to perform, feems to throw confiderable light on the ufe of the cochlea. It cannot be allowed that the preffure of the watery fluid in the labyrinth is a requifite condition to produce the fenfation of hearing, fince all birds hear without any mechanifm for that purpose, but as fuch preffure muft ultimately give increafed tenfion to the feneftra cochleæ, it follows that we inquire, at this part, for the principal ufe of the ftapes. "As the membrane of the feneftra cochleæ is expofed to the air contained within the cavity of the tympanum, it appears adapted to receive fuch founds as pafs through the membrana tympani, without exciting confonant motions in the feries of officula auditus." P. 206. XII. On an artificial Subflance which poffeffes the principal characteristic Properties of Tannin. By Charles Hatchett, Efq. This paper commences with a concife hiftory of the original difcovery of the tanning principle, and of the fublequent obfervations made by various ingenious perfons, relative to its origin, its properties, its exiftence in the various vegetables, which are, on that account, fubfervient to the tanner, &c. This author then fays, that in the course of his experiments, he was convinced that a fubftance poffefsing the chief characteristic properties of tannin, may be eafily formed, not only from vegetable, but even from mineral and from animal fubftances. He defcribes the experiments he made under the influence of that conviction, in confequence of which he difcovered an artificial method of forming a fubftance capable of precipitating glue from its folution in water, and of tanning leather. The fact in fhort is" that a fubftance, very analogous to tannin, which has hitherto been confidered as one of the proximate principles of vegetables, may at any time be produced, by ex |