Front Matter

PHILOSOPHICAL TRANSACTIONS, OF THE ROYAL SOCIETY OF LONDON. FOR THE YEAR MDCCXCVIII. PART I. LONDON, SOLD BY PETER ELMSLY, PRINTER TO THE ROYAL SOCIETY. MDCCXCVIII. 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 advisable, 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. I. The Bakerian Lecture. Experiments upon the Resistance of Bodies moving in Fluids. By the Rev. Samuel Vince, A. M. F. R. S. Plumian Professor of Astronomy and Experimental Philosophy in the University of Cambridge: page 1 II. Experiments and Observations, tending to show the Composition and Properties of Urinary Concretions. By George Pearson, M. D. F. R. S. p. 15 III. On the Discovery of four additional Satellites of the Georgium Sidus. The retrograde Motion of its old Satellites announced; and the Cause of their Disappearance at certain Distances from the Planet explained. By William Herschel, LL.D. F. R. S. p. 47 IV. An Inquiry concerning the Source of the Heat which is excited by Friction. By Benjamin Count of Rumford, F. R. S. M. R. I. A. p. 80 V. Observations on the Foramina Thebesii of the Heart. By Mr. John Abernethy, F. R. S. Communicated by Everard Home, Esq. F. R. S. p. 103 VI. An Analysis of the earthy Substance from New South Wales, called Sydneia or Terra Australis. By Charles Hatchett, Esq. F. R. S. p. 110 VII. Abstract of a Register of the Barometer, Thermometer, and Rain, at Lyndon, in Rutland, for the Year 1796. By Thomas Barker, Esq. Communicated by Mr. Timothy Lane, F. R. S. p. 130 VIII. An Account of some Endeavours to ascertain a Standard of Weight and Measure. By Sir George Shuckburgh Evelyn, Bart. F. R. S. and A. S. p. 133 IX. A new Method of computing the Value of a slowly converging Series, of which all the Terms are affirmative. By the Rev. John Hellins, F. R. S. and Vicar of Potter's-Pury, in Northamptonshire. In a Letter to the Rev. Dr. Maskeleyne, F. R. S. and Astronomer Royal. p. 183 APPENDIX. Meteorological Journal kept at the Apartments of the Royal Society, by Order of the President and Council. CONTENTS. X. A disquisition on the Stability of Ships. By George Atwood, Esq. F. R. S. p. 201 XI. Quelques Remarques d'Optique, principalement relatives à la Réflexibilité des Rayons de la Lumiere. Par P. Prevost, Professeur de Philosophie à Geneve, de l'Académie de Berlin, de la Société des Curieux de la Nature, et de la Société Royale d'Edimbourg. Communicated by Sir Charles Blagden, Knt. F. R. S. p. 311 XII. An Account of the Orifice in the Retina of the human Eye, discovered by Professor Soemmering. To which are added, Proofs of this Appearance being extended to the Eyes of other Animals. By Everard Home, Esq. F. R. S. p. 332 XIII. A Description of a very unusual Formation of the human Heart. By Mr. James Wilson, Surgeon. Communicated by Matthew Baillie, M. D. F. R. S. p. 346 XIV. Account of a singular Instance of atmospherical Refraction. In a Letter from William Latham, Esq. F. R. S. and A. S. to the Rev. Henry Whitfeld, D. D. F. R. S. and A. S. p. 357 XV. Account of a Tumour found in the Substance of the human Placenta. By John Clarke, M. D. Communicated by the Right Hon. Sir Joseph Banks, Bart. K. B. P. R. S. p. 361 XVI. On the Roots of Equations. By James Wood, B.D. Fellow of St. John's College, Cambridge. Communicated by the Rev. Nevil Maskelyne, D. D. F. R. S. and Astronomer Royal. p. 369 XVII. General Theorems, chiefly Porisms, in the higher Geometry. By Henry Brougham, Jun. Esq. Communicated by Sir Charles Blagden, Knt. F. R. S. p. 378 XVIII. Observations of the diurnal Variation of the Magnetic Needle, in the Island of St. Helena; with a Continuation of the Observations at Fort Marlborough, in the Island of Sumatra. By John Macdonald, Esq. In a Letter to the Right Hon. Sir Joseph Banks, Bart. K. B. P. R. S. p. 397 XIX. On the Corundum Stone from Asia. By the Right Hon. Charles Greville, F. R. S. p. 403 XX. An Inquiry concerning the chemical Properties that have been attributed to Light. By Benjamin Count of Rumford, F. R. S. M. R. I. A. p. 449 XXI. Experiments to determine the Density of the Earth. By Henry Cavendish, Esq. F. R. S. and A. S. p. 469 XXII. An improved Solution of a Problem in physical Astronomy; by which, swiftly converging Series are obtained, which are useful in computing the Perturbations of the Motions of the Earth, Mars, and Venus, by their mutual Attraction. To which is added an Appendix, containing an easy Method of obtaining the Sums of many slowly converging Series which arise in taking the Fluents of binomial Surds, &c. By the Rev. John Hellins, F. R. S. Vicar of Potter's Pury, in Northamptonshire. In a Letter to the Rev. Nevil Maskelyne, D. D. F. R. S. and Astronomer Royal. p. 527 XXIII. Account of a Substance found in a Clay-pit; and of the Effect of the Mere of Diss, upon various Substances immersed in it. By Mr. Benjamin Wiseman, of Diss, in Norfolk. Communicated by John Frere, Esq. F. R. S. With an Analysis of the Water of the said Mere. By Charles Hatchett, Esq. F. R. S. In a Letter to the Right Hon. Sir Joseph Banks, Bart. K. B. P. R. S. p. 567 XXIV. A Catalogue of Sanscrita Manuscripts presented to the Royal Society by Sir William and Lady Jones. By Charles Wilkins, Esq. F. R. S. p. 582 Presents received by the Royal Society, from November, 1797 to June, 1798. p. 595 Index. p. 599