Art. VIII. Description of a Set of Halos and Parhelia, seen in the Year 1771, in North-America. By Alexander Baxter, Efq. Thefe phænomena occurred the 22d of January, about two in the afternoon, at Fort Gloucefter, on the river of Lake Superior, fix miles above the Falls of St. Mary's, and as much from the mouth of the river. Befides the principal halo round the fun, there was a luminous circle, parallel to the horizon, paffing through the centre of the halo, in which were five mock funs. Oppofite to the fun was a luminous cross, and in the zenith a femicircle, with the convex part turned towards the fun. Art, IX. Obfervations of the Tranfit of Mercury, May 4, 786, at Drefden. By M. Köhler. Art. X. Obfervations of the Tranfit of Mercury, at St. Pe terfburg. By M. Rumovski. 'Art. XI. Account of the Strata obferved iu finking for water at Bofton in Lincolnshire. By Mr. James Limbird. Without specifying the different ftrata, or the depth of each, we fhall only obferve that at 474 feet from the furface, chalk and gravel were found; and at 468 feet, falt water was drawn up; circumftances which tend to prove that this part of the ifland had long been covered by the fea. Should the work be refumed, there is the ftrongeft reason to expect that fresh water will yet be found, and which will rife to the furface. Art. XII. Obfervations of Mifs Herfchel's Comet, in Auguft and September 1786. By the Rev. Francis Wollafton, LL. B. F.R.S. In examining this comet Mr. Wollafton made ufe of his fyftem of wires, which feems to have answered in a manner not unfatisfactory; and he has given a series of obfervations on the different ftars which the comet preceded or followed. Art. XIII. An Account of a Thunder-ftorm in Scotland; with fome Meteorological Obfervations. By Patrick Brydone, Efq. F.R.S. This thunder-ftorm, which proved fatal to one man, and a few animals, is defcribed by Mr. Brydone with great perfpicuity, and with his usual neatness. Art. XIV. On finding the Values of Algebraical Quantities by converging Seriefes, and demonftrating and extending Propofitions given by Pappus and others. By Edward Waring, F.R.S. As this paper confifts of a series of depending calculations, it is impoffible either to abridge, or give any particular account of it. Art. XV. Experiments on the Production of Dephlogisticated Air from Water with various Subftances. By Sir Benjamin Thompson, Knt. F. R. S. In thefe Experiments Sir Benjamin Thompson employed raw filk, which is found to collect collect air rapidly in water expofed to the light. He discovered that light alone, independently of heat, was the efficient caufe of the production of air; and that the quantity produced was in proportion to the intensity of light, whether the latter proceeded from the fun, or was collected by mirrors from lamps. Sheep's wool, eider down, hare's fur, and cotton wool, fhewed fimilar properties with filk in regard to the collecting of air. Human hair, and the ravellings of linen, feemed to exert very little power in this refpect; but from whatever fubftance the air was fupplied, the water, in confequence of the process, changed to a greenish or a yellowish hue; and the colour appeared to be produced entirely by animalcules. The air from filk was better than that which was procured. from plants in a state of vegetation; and, what was remarkable, the power of the filk did not seem to be exhausted by the repetition of the experiments; nor was its appearance altered in any refpect. When the animalcules were formed, pure air was produced even by water itself, without the addition of any other fubftance. Art. XVI. An Account of the Discovery of two Satellites revolving round the Georgian Planet. By William Herschel, LL.D. F.R. S. These fatellites were difcovered on the 11th of January, 1787, in confequence of an improvement made by Dr. Herschel on his telescope, by which it gained more light. So far as he could follow them by his obfervations, he thinks that one performs a fynodical revolution in about eight days and three quarters, and the other in nearly thirteen days and an half. Art. XVII. Remarks on Mr. Brydone's Account of a remarkable Thunder-ftorm in Scotland. By the Right Hon. Earl Stanhope, F.R.S. This phænomenon being fo well authenticated, his lordship attempts to account for the circumstances attending it by the laws of electricity, the operation of which, in the prefent inftance, he confiders as a demonftrable fact. Art. XVIII. Concerning the Latitude and Longitude of the Royal Obfervatory at Greenwich; with Remarks on a Memorial of the late M. Caffini de Thury. By the Rev. Nevil Maskelyne, D. D. F. R. S. M. Caffini de Thury, in a memoir prefented to the Royal Academy of Sciences, had afferted that the latitude of Greenwich was not afcertained within 15". The aftronomer royal, with a becoming zeal of doing justice to the memories of his learned predeceffors, and to himself, evinces that the latitude of Greenwich has been fixed with confiderable precifion. He explains the various methods employed for this purpose, both by his predeceffor Dr. Bradley and himself; whence it appears, from a mean of two determinations in different ways, that that the latitude is 51° 28' 40". Dr. Mafkelyne, in examining the causes of M. Caffini's mistake, imputes it to a passage in a memoir of the Abbé de la Caille on aftronomical refractions, and the latitude of Paris, in the French Memoirs for 1755. It is probable that the error arofe from fome little defect in the inftruments, and the table of refractions employed by the Abbé. The limits of a Review will not permit us to exhibit the numerous remarks and calculations of the Aftronomer Royal on this fubject; but we cannot conclude without obferving that he has conducted the investigation with great precifion and perfpicuity. Art. XIX. An Account of the Mode propofed to be followed in determining the relative Situation of the Royal Obfervatories of Greenwich and Paris. By Major-General Wil– liam Roy, F. R. S. and A. S. It is impoffible to convey any adequate idea of this method without the affiftance of the plan which accompanies it; but from the diftinguished abilities of thofe who are engaged in the operation, the accuracy of the inftruments with which they were furnished, and the proof of attention which has already appeared in the menfuration of the bafe by the fame author, we may be affured that the relative fituation of the two obfervatories will be ascertained with the greatest exactnefs. Art. XX. An Account of Three Volcanos in the Moon. By William Herfchel, LL.D. F.R.S. This paper, though fhort, is, like the other ingenious communications of the fame author, highly interefting to curiofity. Dr. Herschel has, with his telescope, discovered fome luminous fpots on the dark portion of the moon, where they frequently change their appearance, and fometimes even difappear. They must therefore be produced by fome active power in the body of that planet; which power, from its light, we may confidently affirm to be fire. Hence Dr. Herfchel, with great reason, supposes those spots to be volcanos. The largest is judged to be nearly three miles in diameter. Though our delay in giving an account of the Philofophical Tranfactions was originally occafioned by accident, we now have reason to think that it has been productive of fome advantage. For the narrative, being thus regularly continued, affords at leaft an opportunity of tracing more diftinctly the progress of fcience. We fhall therefore proceed in the detail without interruption; and comprife, in a few more numbers of our Journal, what yet remains unnoticed of the Philofophical Transactions, down to the prefent time. ART. VIII. An Inquiry into the Small-Pox, medicat and political; wherein a fuccessful Method of treating that Difeafe is propofed, the Caufe of Pits explained, and the Method of their Prevention pointed out; with an Appendix, representing the prefent State of Small-Pox. By Robert Walker, M. D. Fellow of the Royal College of Surgeons, Edinb. 8vo. 6s. boards. Murray, London; Creech, Edinburgh. 1790. HOW much the improvement of medicine has been obftructed by the prejudice of authority, is in nothing fo confpicuous as in the fmall-pox; which, though a disease almost univerfally incident to the human race, and treated by innumerable writers from Rhazes down to the present time, yet remains, with regard both to its nature and method of cure, in a ftate of great imperfection. That the cool regimen is of much importance in this, as well as every other acute diftemper, is a truth afcertained beyond all poffibility of queftion; but it is not alone fufficient for fuppreffing the violence of those symptoms that occur in all the bad kinds of fmall-pox. Hence the continuance, if not really the increase, of mortality which still prevails remarkably in the natural fpecies of the difeafe. From this confideration the author of the present treatife has been induced, for many years paft, to pay particular attention to the worft kinds of fmall-pox; on which it must be acknowledged that his practical obfervations are tranfcendently judicious and valuable, at the fame time that they are intimately connected with a theory which feems not to be more fupported by just and ingenious reasoning than by fact and experience. Dr. Walker begins with reciting the firft accounts of the fmall-pox, and opinions concerning its origin, The most an- / cient writers on the disease are doubtlefs the Arabians; but whether it was a diftemper indigenous amongst that people, is a point not pofitively determined. The learned Dr. Freind, as our author obferves, fuggefts the idea that they had probably derived the infection from fome of the more diftant regions of the Eaft; and indeed this opinion feems to receive confirmation from the account related by Mr. Holwell, who refided long in India, where the Bramins appear to have been acquainted with the disease from a very remote period. The Arabians, from whatever quarter they imported it, brought the difeafe at first into Egypt, and afterwards carried it, in the course of their conquefts, into Europe. But the great epoch of its diffemination was the expedition of the crufades; in confequence of which we learn, from John of Gaddeston, an English physician, that the the small-pox was common in Britain about the end of the twelfth century. Though every reafon juftifies the inference that the remote caufe of the small-pox is contagion, there are not wanting some writers who maintain it to be merely an inflammation, fui generis; obferving, in fupport of this opinion, that the disease frequently invades foon after excefs in eating, drinking, violent exercife, or change of air. But it is evident, from this remark, that they confound the remote with the occafional causes. We know that various abuses of the non-naturals will act in the capacity of the latter; but we have no proof that any thing else than variolous particles, vifible or invifible, can actually communicate the small-pox. Our author justly observes, that, from the confideration of this contagion producing no pernicious effect upon those who are not fufceptible of the disease, we cannot reasonably fuppofe it to be poffeffed of thofe virulent and deleterious qualities which have been afcribed to it by fome phyficians; and that, though inflammation be the first obvious effect of variolous matter introduced under the cuticle, there appears an evident difference between this and every other inflammatory affection. For, as neither fimple inflammation, nor the highest degree of it, ever proves contagious, it would appear that variolous contagion must be endowed with a property diftinct from every common inflammation, by which it is rendered contagious. The confideration of variolous contagion being an animal production, and that a peculiar foetor conftantly attends the disease, are circumftances which very juftly induce our author to regard the inflammatory principle of the fmall-pox as poffeffing somewhat of a feptic quality; and for this opinion refpecting the nature of the variolous contagion, he adduces the following obfervations: Every species of fmall-pox we are acquainted with, or that have been described by authors, feems to point out the exiftence of the inflammatory-feptic principle, from whence they originate. In the contiguous fpecies, where the puftules are numerous, a confiderable degree of inflammation attends every ftage of the difeafe; at the fame time, the fœtor is very confiderable, and the fccond fever is commonly of the putrid kind. In the confluent and more malignant fpecies, the eruptive fever, and other fymptoms, indicate great inflammation, and the foetor conftant and great. Beides, wo frequently find, that this fever, fooner or later in the congle of the dis. ease affumes another type; a fudden proftration of it ength comes on; the interftices of the puftules are occupied with petechia, and followed with hemorrhages from the nofe, lungs, uterus, &c. and the fœtor highly offenfive. In every cafe of fmall-pox, therefore, we have evidence of the prefence of this principle, the mildeft fpecies |