Front Matter

ADVERTISEMENT. The Committee appointed by the Royal Society to direct the publication of the Philosophical Transactions, take this opportunity to acquaint the Public, that it fully appears, as well from the council-books and journals of the Society, as from repeated declarations, which have been made in several former Transactions, that the printing of them was always, from time to time, the single act of the respective Secretaries, till the Forty-seventh Volume: the Society, as a body, never interesting themselves any further in their publication, than by occasionally recommending the revival of them to some of their Secretaries, when, from the particular circumstances of their affairs, the Transactions had happened for any length of time to be intermitted. And this seems principally to have been done with a view to satisfy the Public, that their usual meetings were then continued for the improvement of knowledge, and benefit of mankind, the great ends of their first institution by the Royal Charters, and which they have ever since steadily pursued. But the Society being of late years greatly enlarged, and their communications more numerous, it was thought adviseable, that a Committee of their members should be appointed to reconsider the papers read before them, and select out of them such, as they should judge most proper for publication in the future Transactions; which was accordingly done upon the 26th of March 1752. And the grounds of their choice are, and will continue to be, the importance and singularity of the subjects, or the advantageous manner of treating them; without pretending to answer for the certainty of the facts, or propriety of the reasonings, contained in the several papers so published, which must still rest on the credit or judgment of their respective authors. It is likewise necessary on this occasion to remark, that it is an established rule of the Society, to which they will always adhere, never to give their opinion, as a body, upon any subject, either of Nature or Art, that comes before them. And therefore the thanks, which are frequently proposed from the chair, to be given to the authors of such papers, as are read at their accustomed meetings, or to the persons through whose hands they receive them, are to be considered in no other light than as a matter of civility, in return for the respect shewn to the Society by those communications. The like also is to be said with regard to the several projects, inventions, and curiosities of various kinds, which are often exhibited to the Society; the authors whereof, or those who exhibit them, frequently take the liberty to report, and even to certify in the public newspapers, that they have met with the highest applause and approbation. And therefore it is hoped, that no regard will hereafter be paid to such reports, and public notices; which in some instances have been too lightly credited, to the dishonour of the Society. CONTENTS OF VOL. LXXIII. PART I. I. A LETTER from William Herschel, Esq. F. R. S. page 1 II. On the Diameter and Magnitude of the Georgium Sidus; with a Description of the dark and lucid Disk and Periphery Micrometers. By William Herschel, Esq. F. R. S. p. 4 III. Conclusion of the Experiments and Observations concerning the Attractive Powers of the Mineral Acids. By Richard Kirwan, Esq. F. R. S. p. 15 IV. A Description of a Species of Sarcocele of a most astonishing Size in a Black Man in the Island of Senegal; with some Account of its being an endemic Disease in the Country of Galam. By J. P. Schotte, M. D.; communicated by Sir Joseph Banks, Bart. P. R. S. p. 85 V. A Description of a new Construction of Eye-glasses for such Telescopes as may be applied to Mathematical Instruments. By By Mr. Ramsden; communicated by Sir Joseph Banks, Bart. P. R. S. p. 94 VI. Account of several Lunar Iris. By Marmaduke Tunstall, Esq. F. R. S. in Two Letters to Sir Joseph Banks, Bart. P. R. S. p. 100 VII. Account of an Earthquake. By John Lloyd, Esq. in a Letter to Sir Joseph Banks, Bart P. R. S. p. 104 VIII. An Account of a new Eudiometer. By Mr. Cavendish, F. R. S. p. 106 IX. Experiments upon the Resistance of the Air. By Richard Lovell Edgworth, Esq. F. R. S. In a Letter to Sir Joseph Banks, Bart. P. R. S. p. 136 X. An Answer to the Objections stated by M. De la Lande, in the Memoirs of the French Academy for the Year 1776, against the Solar Spots being Excavations in the luminous Matter of the Sun, together with a short Examination of the Views ascertained by him upon that Subject. By Alexander Wilson, M. D. Professor of Practical Astronomy in the University of Glasgow; communicated by Nevil Maskelyne, D D. F. R. S. and Astronomer Royal. p. 144 XI. An Account of the Earthquakes which happened in Italy, from February to May 1783. By Sir William Hamilton, Knight of the Bath, F. R. S.; in a Letter to Sir Joseph Banks, Bart. P. R. S. p. 169 XII. Account of the Earthquake which happened March 28, 1783. In a Letter from Count Francesco Ippolito to Sir William Hamilton, Knight of the Bath, F. R. S.; presented by Sir William Hamilton. p. 117 XIII. Account of the Black Canker Caterpillar, which destroys the Turnips in Norfolk. By William Marshall, Esq. in a Letter to Charles Morton, M. D. F. R. S. p. 217 CONTENTS. XIV. A Letter from Mr. Edward Nairne, F.R.S. to Sir Joseph Banks, Bart. P.R.S. containing an Account of Wire being shortened by Lightning. p. 223 XV. An Account of Ambergrise. By Dr. Schwediawer; presented by Sir Joseph Banks, Bart. P.R.S. p. 226 XVI. Extract of a Register of the Barometer, Thermometer, and Rain, kept at Lyndon, in Rutland, 1782. By Thomas Barker, Esquire. p. 242 APPENDIX. I. Translation of Count Francesco Ippolito's Letter to Sir William Hamilton, Knight of the Bath, F.R.S.; giving an Account of the Earthquake which happened in Calabria, March 28, 1783. p. i CONTENTS OF VOL. LXXIII. PART II. XVII. On the proper Motion of the Sun and Solar System; with an Account of several Changes that have happened among the fixed Stars since the Time of Mr. Flamsteed. By William Herschel, Esq. F. R. S. page 247 XVIII. Some Experiments upon the Ochra friabilis nigro-fusca of Da Costa, Hist. Foss. p. 102.; and called by the Miners of Derbyshire, Black Wadd. By Josiah Wedgwood, F. R. S. p. 284 XIX. Mémoire sur la Manière de préparer, avec le moins de perte possible, le Sel fusible d’Urine blanc, et pur, et l’Acide phosphorique parfaitement transparent. By the Duke de Chaulnes, F. R. S. presented by Sir Joseph Banks, Bart. P. R. S. p. 288 *XX. Experiments for ascertaining the Point of Mercurial Congelation. By Mr. Thomas Hutchins, Governor of Albany Fort, in Hudson’s Bay. p. *303 CONTENTS. XX. Observations on Mr. Hutchins's Experiments for determining the Degree of Cold at which Quicksilver freezes. By Henry Cavendish, Esq. F. R. S. p. 393 XXI. History of the Congelation of Quicksilver. By Charles Blagden, M. D. F. R. S. Physician to the Army. p. 329 XXII. Experiments relating to Phlogiston, and the seeming Conversion of Water into Air. By Joseph Priestley, LL. D. F. R. S.; communicated by Sir Joseph Banks, Bart. P. R. S. p. 398 XXIII. Description of an improved Air-Pump, and the Account of some Experiments made with it. By Mr. Tiberius Cavallo, F. R. S. p. 435 XXIV. Extract of a Letter from the Rev. James Augustus Hamilton, M. A. to the Rev. Nevil Maskelyne, D. D. F. R. S. giving an Account of his Observation of the Transit of Mercury over the Sun, of Nov. 12, 1782, observed at Cook's Town, near Dungannon, in Ireland. p. 453 XXV. Methodus Inveniendi Lineas Curvas ex Proprietatibus Variationis Curvaturae. Auctore Nicolao Landerbeck, Mathef. Profess. in Acad. Upsaliensi Adjuncto; communicated by Nevil Maskelyne, D. D. F. R. S. and Astronomer Royal. p. 456. XXVI. A Series of Observations on, and a Discovery of, the Period of Variation of the Light of the bright Star in the Head of Medusa, called Algol. In a Letter from John Goodricke, Esq. to the Rev. Anthony Shepherd, D. D. F. R. S. Plumian Professor of Astronomy in Cambridge. p. 474.