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 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 and Calculations relative to physical Optics. By Thomas Young, M. D. F. R. S. page 1 II. Continuation of an Account of a peculiar Arrangement in the Arteries distributed on the Muscles of slow-moving Animals, &c. In a Letter from Mr. Anthony Carlisle to John Symmons, Esq. F. R. S. p. 17 III. An Account of a curious Phenomenon observed on the Glaciers of Chamouny; together with some occasional Observations concerning the Propagation of Heat in Fluids. By Benjamin Count of Rumford, V. P. R. S. Foreign Associate of the National Institute of France, &c. &c. p. 23 IV. Description of a triple Sulphuret, of Lead, Antimony, and Copper, from Cornwall; with some Observations upon the various Modes of Attraction which influence the Formation of mineral Substances, and upon the different Kinds of Sulphuret of Copper. By the Count de Bournon, F. R. S. and L. S. p. 30 V. Analysis of a triple Sulphuret, of Lead, Antimony, and Copper, from Cornwall. By Charles Hatchett, Esq. F. R. S. p. 63 VI. Observations on the Orifices found in certain poisonous Snakes, situated between the Nostril and the Eye. By Patrick Russell, M. D. F. R. S. With some Remarks on the Structure of those Orifices; and the Description of a Bag connected with the Eye, met with in the same Snakes. By Everard Home, Esq. F. R. S. p. 70 VII. An Enquiry concerning the Nature of Heat, and the Mode of its Communication. By Benjamin Count of Rumford, V.P.R.S. Foreign Associate of the National Institute of France, &c. p. 77 VIII. Experiments and Observations on the Motion of the Sap in Trees. In a Letter from Thomas Andrew Knight, Esq. to the Right Hon. Sir Joseph Banks, Bart. K.B. P.R.S. p. 183 APPENDIX. Meteorological Journal kept at the Apartments of the Royal Society, by Order of the President and Council. THE PRESIDENT and COUNCIL of the ROYAL SOCIETY adjudged, for the Year 1803, the Medal on Sir GODFREY COPLEY's Donation, to RICHARD CHENEVIX, Esq. F. R. S. for his various chemical Papers, printed in the Philosophical Transactions. CONTENTS. IX. Analytical Experiments and Observations on Lac. By Charles Hatchett, Esq. F. R. S. p. 191 X. On the Integration of certain differential Expressions, with which Problems in physical Astronomy are connected, &c. By Robert Woodhouse, A. M. F. R. S. Fellow of Caius College. p. 219 XI. Observations on Basalt, and on the Transition from the vitreous to the stony Texture, which occurs in the gradual Refrigeration of melted Basalt; with some geological Remarks. In a Letter from Gregory Watt, Esq. to the Right Hon. Charles Greville, V. P. R. S. p. 279 XII. An Analysis of the magnetical Pyrites; with Remarks on some of the other Sulphurets of Iron. By Charles Hatchett, Esq. F. R. S. p. 315 XIII. Remarks on the voluntary Expansion of the Skin of the Neck, in the Cobra de Capello or hooded Snake of the East Indies. By Patrick Russell, M.D. F. R. S. With a Description of the Structure of the Parts which perform that Office. By Everard Home, Esq. F. R. S. p. 346 XIV. Continuation of an Account of the Changes that have happened in the relative Situation of double Stars. By William Herschel, LL. D. F. R. S. p. 353 XV. Observations on the Change of some of the proximate Principles of Vegetables into Bitumen; with analytical Experiments on a peculiar Substance which is found with the Bovey Coal. By Charles Hatchett, Esq. F. R. S. p. 385 XVI. On two Metals, found in the black Powder remaining after the Solution of Platina. By Smithson Tennant, Esq. F. R. S. p. 411 XVII. On a new Metal, found in crude Platina. By William Hyde Wollaston, M. D. F. R. S. p. 419 ERRATUM In Part I. page 145, line 20, for 9199, read 9919. The three Plates in the second Part are numbered VII, VIII, IX, instead of VI, VII, VIII.