will be pleased with recollecting, on this occafion, the ceremonies of his college-the cafe frondeæ pro tabernaculis, in the window recefles of the Lower School, and the arbours in Long Chamber, for which, if I miftake not, a waggon-load of boughs is provided at the expenfe of the college; and this happening at the time of the annual election of candidates for the univerfity, feem referrible to this, and may be remains of the old northern cuftom of electing under the bough? And I hope it may not be deemed too fanciful, if I fuppofe that Thefeus elected his magiftrates at the feaft of the Bough, at the fummer folftice, that they might enter upon their office at the firft new moon." P. 118. 1. THE Croonian Lecture. On By the Irritability of Nerves. Everard Home, Efq. F.R.S.-II. The Bakerian Lecture. On the Mecha nifm of the Eye. By Thomas Young, M. D. F. R.S.—III. On the neceffary Truth of certain Conclufions obtained by Means of imaginary Quantities. By Robert Woodhoufe, A. M. Fellow of Caius College.-IV. On the Production of artificial Cold by Means of Muriate of Lime. By Mr. Richard Walker.-V. Ac. count of a monstrous Lamb. In a Letter from Mr. Anthony Carlisle, to the Right Hon. Sir Jofeph Banks, Bart. K. B. P. R. S.-VI. An anatomical Description of a male Rhinoceros. By Mr. H. Leigh Thomas, Surgeon.-VII. Demonftration of a Theorem, by which fuch Portions of the Solidity of a Sphere are affigned as admit an algebraic Expreffion. By Robert Woodhoufe, A. M. Fellow of Caius College, Cambridge.-VIII. Account of the Difcovery of Silver in Herland Copper Mine. By the Rev. Malachy Hitchins.-IX. Ac count of an Elephant's Tufk, in which the Iron Head of a Spear was found imbedded. By Mr. Charles Combe.-X. Defcription of the Arfeniates of Copper, and of Iron, from the County of Cornwall. By the Count de Bournon.-XI. Analyfis of the Arfeniates of Copper, and of Iron, described in the preceding Paper; likewife an Analysis of the red octaedral Copper Ore of Cornwall; with Remarks on fome particular Modes of Analyfis. By Richard Chenevix, Efq. M. R.I.A. Appendix. Meteorological Journal kept at the Apartments of the Royal Society, by Order of the President and Council. EXTRACTS. ON THE IRRITABILITY OF NERVES, BY EVERARD HOME, ESQ. F.R.S. "THE nerves have been hitherto confidered as chords that have no powers of contraction within themfelves, but only serving as a medium, by means of which the influence of the brain may be communicated to the mufcles, and the impreffions made upon different parts of the body conveyed to the brain. attempt to inveftigate the real state of the nerves in the living body, and the impoflibility of acquiring any informa tion upon this fubject after death, may be urged in excufe for this opinion having been fo univerfally received, fince it will be found, from the following experiments and obfervations, to be void of foundation. "The difficulties which attend every knowledge refpecting the irritability of "The only means by which any the operations in furgery performed nerves can be procured, must be from upon nerves, either in a healthy ftate, or under the influence of disease; or from experiments made upon animal bodies before they are wholly deprived of life, and instituted for that particu lar purpofe. My attention was directed to this fubject by the following cafe, which ing the actions of the nerves when unexplains many circumftances respectder the influence of difeafe, and gave rife to the experiments and obfervations contained in this Paper. "A perfon Philofophical Transactions of the Royal Society of London, for 1801. 447 "A person thirty-fix years of age, naturally eager and anxious in his difpofition, whofe ftomach was peculiarly irritable and irregular in its action, in the winter of the year 1796, while riding in the country, was thrown from his feat by a fudden motion of the horse; and, in endeavouring to fave himself, fell with his whole weight upon the end of his thumb, againft the pommel of the faddle. "The part fwelled, and became very painful. A few days after, he hurt it again, which prevented the fwelling from fubfiding, and it remained uneafy and enlarged for three or four months. It afterwards got well, but the motions of the thumb were not always under the command of the will; fo that he was fenfible, in the years 1797 and 1798, while writing, of finding a difficulty in forming particular letters. "On the evening of the 16th of October 1799, which was cold and damp, he was travelling in a poft-chaife with two other perfons, and let down the window, to speak to the driver. A cold wind blew directly into the carriage, and he endeavoured to pull up the window; but not seeing the glafs rife, he looked down, and his hand, inftead of pulling up the window, was lying upon his knee. The thumb was bent in towards the palm of the hand; a fpafm came upon the muscles of the arm, making them bend the elbow; and immediately he became infenfible : in a quarter of an hour he perfectly recovered himself. Some hours after, upon bending his thumb, to fhow what had happened to him in the carriage, there was a return of the fame attack, which alfo rendered him infenfible for a few minutes. "From this time, he had no return of these attacks for nine weeks; at the end of which period, on the 18th of December 1799, he was waving his hand over his head, with a degree of eagerness, as a fign for fome people to make hafte and follow him; this exertion made the thumb contract towards the palm of the hand, and he fell upon the ground in a ftate of infenfibility. This attack went off as the others had done; he had another in the evening; and, in the courfe of the next day, two more, equally violent. As the motion of the thumb was the first symptom in all these attacks, the affiftants were led to contrive a glove, the front of which was ftrong enough to refift the motion of the thumb, and to keep it in its place: while this was kept on, the attacks were lefs frequent. A ligature was then applied round the fore-arm; when the thumb was beginning to be agitated, this was tightened, and the fpafms were found to be arrested at the ligature, and of courfe deprived of their violence. "From this time, a tourniquet was kept conftantly upon the fore-arm; and a perfon was always in readiness to tighten it, the moment the fpafm was expected, which was always preceded by a general feel of uneafinefs all over the body: as foon as the spasm went off, which it did inftantaneously, the tourniquet was loofened. The fpafms in the thumb and fore-arm returned frequently, and at irregular intervals, generally every three hours, fometimes oftener, and once did not come on for thirty-fix hours. "On the third or fourth day, electricity was tried, with a view to relieve them; sparks drawn from the thumb, produced tremors in the muscles, which were confined to the thumb. An electric fhock through the ball of the thumb, brought on a very severe spasm in the arm; but neither sparks, nor a fhock through the other thumb, produced any fenfible effect. "On the 29th of December, I first faw the patient; and, after watching the fymptoms for three days, made the following obfervations upon the complaint. "That the beginning of the attack was fome involuntary motion of the thumb and fore-finger; and therefore, the disease appeared to be in the branch of the nerve which fupplies thefe two parts, called by Winslow the median nerve. "That the progrefs of the fpafms was in the direct course of the trunks of the median nerve, up to the head. "That compreffing the parts in the course of that nerve, when it was done before the fpaims had reached them, always arrefted their progrefs; but, when once the mufcles had become convulfed, or agitated, the fame compreflion had no effect in stopping the progrefs of the ipaims. << The "The mode in which the fpafms were propagated along the course of the nerves, was as follows. "Five or fix tremors took place in the flexors of the thumb and fore-finger; then fimilar convulfive motions affected the mufcles of the fore-arm; foon after, the mufcles of the arm were thrown into the fame kind of action; afterwards the pectoral mufcle, and scaleni of the neck: the mufcles of the lower jaw were probably in the fame ftate, although their action was not within the notice of the by-flanders. The head was pulled forcibly to that fide, in quick fucceffive motions, and, in a fecond or two, the whole ceased; the parts became tranquil, the infenfibility went off, and the patient recovered himself: there was, however, a general feel of languor and diftrefs over the whole body, before the recovery. "From thefe obfervations, the difeafe appeared to be decidedly in the inferior branches of the median nerve; and the irritation was conveyed along its course, from its terminations in the thumb and fore-finger, to the origin in the brain. "It was propofed to divide the nerve, as it pafies from under the annular ligament of the wrift towards the thumb, to cut off the communication between the diseased extremities and the trunk of the nerve, and fo put a ftop to the progrefs of irritation which conftituted the difeafe. "That fuch an operation might be attended with fuccefs, was not only rendered probable from reafoning, but the performing it was fully juftified by the fuccefs which had been experienced from a fimilar operation, in fome cafes of the Tic douleureux; a difeafe, in many refpe&ts, of the fame nature with the prefent. "All thefe circumftances were explained to the patient, who, from a defire of obtaining relief, confented to have the nerve divided. This was done on the ift of January 1300, in the following manner: the nerve, as it pafles from under the annular ligament, towards the thumb and fore-finger, was laid bare, for above an inch in length; it was then detached from its lateral connexions, and, in this expofed state, a probe-pointed biftoury was paffed behind it, and the nerve was raised upon the edge of the inftrument, fo as to be diftinctly feen by the different medical gentlemen prefent, before it was cut through. As foon as it was divided, the two cut ends retracted from one another, to a confiderable distance. This retraction was very unexpected, as the nerve was difengaged from the cellular membrane, and no other part had been divided, whofe action could make the portions of the nerve recede. "That nerves, when divided, do retract, is well known in the practice of furgery; but this effect has been ufually attributed to the contraction of the neighbouring parts, as the cellular membrane, and blood-vcffels, with which the nerves are connected. As none of thefe caufes could produce the effect in the prefent inftance, it was natural to fuppofe, that an independ ent action exifted in the nerve itfel, which had been fo much increased by the influence of difeafe, as to become unufually great; and, therefore, the retraction was more diftinctly feen than in a healthy ftate of the body. "The moment the nerve was divided, there was a fpafin over the whole body, and a momentary infenfibility. The blood-veifels divided in the opera tion were not fecured by ligature, but allowed to ftop of themselves, to give the wound every chance of healing by the firft intention. The edges of the fkin were carefully brought together, and kept in that itate by compreis and bandage, to promote as much as poffible the union. "For eight hours after the operation, the parts were perfectly quiet, and there was no fpafin. The wound then began to feel hot, as if a red-hot coal had been applied to it. To relieve this fenfation, the outer, bandage was loofened, and immediately there were twitches in the nerve, which foon went off. The patient felt himself generally unwell, extremely nervous, and irritable. "Fifteen hours after the operation, he had a violent fpafm, which went along the arm to the head, but did not affect the brain. In an hour, there was a fecond attack, at which I was prefent; the pulfe was one hundred and five in a minute, the tongue white, a great deal of general irritation, nervous twitches all over the body, but in the greateft degree in the arm and leg of that fide. The fliff-fronted glove was Philofophical Transactions of the Royal Society of London, for 1801. 449 was now put on, to confine the thumb." P. 1. "The fifth day, fuppuration took, place in the wound; the fwelling in the hand was much abated; and the patient was able to drefs and fhave without fpafm, having only twitches in the fingers, and tremors in the forearm." P. 7 .7. "The fixteenth day, the wound was entirely healed; and, as there had been no return of fpafms, the patient was confidered as well. "On the twenty-fourth day, which was a fortnight after the fpafms had ceafed, at nine o'clock in the morning, he was awakened by a violent fpafra, which paffed directly up to the head, and affected the brain, producing infenfibility: this was the only time the brain had been affected fince the operation." P. 8. "The return of the fpafms after the wound had been healed, made it evident, that the operation of dividing the nerve had not anfwered the purpofe which was expected from it. The failure probably arofe from the wound not healing by the first intention: the confequent inflammation rendered the cut end of the nerve uncommonly irritable; and, in this flate, the confinement in the hard thickened cicatrix, rendered it liable to be ftretched by every motion of the thumb, fo as to bring on fpafinodic contractions. "From this time the patient was not under my direction; but I understood, that he tried the effect of large dofs of opium, which did not afford relief. He was then induced to employ electricity, which was alfo unfuccefefal; and he died in a fit, which at the time was believed to be apoplexy, about five months after the operation had been performed; but, as the body was not examined, the nature of the fit could not be afcertained." P. 9. "It commences in a valley on the weft, and pafles through a hill, which is firft of steep and then of moderate afcent, for upwards of half a mile caftward; when the principal copper lodes, which follow this direction, meet with a large crofs lode, by which, and by other crofs courfes and fleokans, which interfest them in their farther progrefs, they are repeatedly heaved, and fo difordered by thefe heaves, in their form and pofition, and fo changed by them, in refpect to their compofition, as hardly to be recognised. "The ftrata of the diftrict in which this takes place, confit of the common metalliferous fort of argillaceous flate called Killas. "The copper lodes of this diftrict are remarkable for the fhortness of their continuity; for, whereas other lodes may be trated to an indefinite extent in the fame line of direction, thefe, on the contrary, are observed to taper away gradually, and terminate to all appearance, at a short distance, completely and irrecoverably. "This mine was worked about twenty years ago, when it was funk to the depth of one hundred fathoms from the furface. It was again fet to work about eight years fince; has now four fire-engines and two fteam-whims on it; and is funk to a depth of one hundred and fifty-five fathoms below the furface, or, as the miners call it, from grass. "It is in this latter period of its hiflory that a difcovery has been made of a confidgiable quantity of filver ore, in a particular part of the mine, the fingalarity of which discovery, in this country, has much excited the curiofity of the public. "For, although the numerous veins of lead in Cornwall are richly impreg noted with filver, and occasionally yield, fmall quantities of filver ores, and even fpecimens of native ilver, yet, hitherto, no inftance had been known of their yielding this precious metal in fuch abundance; nor had any circumftances, in the natural history of the mineral veins of this country, borne any analogy to thofe which accompanied the prefent difcovery." P. 159. "The filver ore, ftrictly speaking, is a mixture of galena, native bifmuth, gray cobalt ore, vitreous filver ore, and native filver; which, in refpect to their proportions, follow the order in which they are here enumerated, the galena being the most prevalent. The native filver, of which fpecimens of the greatest beauty have been referved for the cabinets of the curious, is found chiefly in a capillary form, in the natural cavities of the lode. "About one hundred and eight tons of this ore have been raised. The miners continue to fink near the fame point of interfection; and feem confident that both lodes will foon become richer, becaufe fimilar inftances of declension and recovery have frequently occurred in the copper lodes of this mine, and because the two lodes appear to have a reciprocal influence on each other. "Unfortunately, however, the extent of their fpeculation is limited by the great depth of the prefent workings; for, forty-five fathors have been funk fince the firft difcovery of the filver; and twenty, or twenty-five fathoms more, are as much as can be funk in this mine, with its prefent mechanical powers of drawing the water; at which level, viz. one hundred and eighty fathoms from the furface, it would be fomewhat deeper than any mine in Cornwall, and about one hundred and thirty fathoms below the level of the fea, at low water mark." P.163. LXXVIII. Struve on the Art of reco vering fufpended Animation. (Concluded from p. 403.) ROYAL HUMANE SOCIETY "IN the year 1772, a humane inftitution for the fame benevolent purpose was formed at Paris, under the direction of M. Pia. "But the most celebrated association in the world, for this purpose, is the Royal Humane Society of London. Dr. Cogan's tranflations of the tranfactions of the fociety at Amfterdam, first excited the attention of the English to this important fubject; he soon sketched a plan for a fimilar inftitution, which met with univerfal approbation, and speedily obtained the fanction of the legiflature. "In the year 1774, feveral medical gentlemen, as well as others of the first refpectability, affociated for the purpose of refufcitating perfons drowned, 2 fuffocated, &c. The founders of this fociety were Dr. Cogan and Dr.Hawes: they afterwards requested the patronage of his Majefty, and the inftitution was confequently called the Royal Humane Society. They immediately published concife directions for the treatment of the drowned, or otherwise apparently dead by fuffocation, &c. of which many thoufand copies were dif tributed. Thefe directions are very elegantly printed on cards, of a pocket fize. A reward of two guineas was offered to those who should firft refeue a perfon from danger; and four guineas to him who fhould be fuccefsful in employing the restorative process. The fociety then nominated a confiderable number of medical affistants, especially fuch as refided near the banks of rivers and the fea-coaft, in order to afford the moft fpeedy relief to perfons drowned, fuffocated, &c. the inftruments neceffary for faving life being depofited in adjacent houfes. To excite emulation and ftimulate industry, a gold and filver prize medal were granted by the fociety as a reward. "In 1775 and 1776, inftitutions fimilar to that of the Royal Humane Society, were formed in all the large towns of the kingdom, especially at Norwich, Hull, Liverpool, Worcester, Chefter, and Kidderminster; as well as in Scotland and Ireland. This refpectable fociety annually increased in the number of its members, who were active in their endeavours to diffufe the knowledge of thofe principles, fo that the prejudices against the inftitution, and the refufcitative process, foon vanifhed; for, within the fhort period of a few years, they had demonftrated by feveral hundred fuccefsful inftances, that their benevolent plan was by no means chimerical. Contributions, fome of which amounted to a hundred pounds, were fent from every part of Great Britain, and even from America; collections were made in the churches of London, by which the fociety was enabled to extend the fphere of its operations, and to appropriate confiderable fums for the purchase of the requifite implements, and for bestowing medals and rewards. In order to carry their intentions into effect, as extensively as poffible, feveral houses were erected for the reception of bodies apparently lifelefs; where all the necellary apparatus, fuch as blankets, a portable |