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 judgement 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 received them, are to be considered in no other light than as a matter of civility, in return for the respect shown to the Society by those communi- cations. 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. The Meteorological Journal hitherto kept by the Assistant Secretary at the Apart- ments of the Royal Society, by order of the President and Council, and published in the Philosophical Transactions, has been discontinued. The Government, on the recommendation of the President and Council, has established at the Royal Obser- vatory at Greenwich, under the superintendence of the Astronomer Royal, a Magnet- ical and Meteorological Observatory, where observations are made on an extended scale, which are regularly published. These, which correspond with the grand scheme of observations now carrying out in different parts of the globe, supersede the necessity of a continuance of the observations made at the Apartments of the Royal Society, which could not be rendered so perfect as was desirable, on account of the imperfections of the locality and the multiplied duties of the observer. A List of Public Institutions and Individuals, entitled to receive a copy of the Philosophical Transactions of each year, on making application for the same directly or through their respective agents, within five years of the date of publication. In the British Dominions. The Queen's Library. The Admiralty Library. The Radcliffe Library, Oxford. The Royal Geographical Society. The United Service Museum. The Royal College of Physicians. The Society of Antiquaries. The Linnean Society. The Royal Institution of Great Britain. The Society for the Encouragement of Arts. The Geological Society. The Horticultural Society. The Royal Astronomical Society. The Royal Asiatic Society. The Royal Society of Literature. The Medical and Chirurgical Society. The London Institution. The Entomological Society of London. The Zoological Society of London. The Institute of British Architects. The Institution of Civil Engineers. The Cambridge University Philosophical Society. The Royal Society of Edinburgh. The Royal Irish Academy. The Royal Dublin Society. The Asiatic Society at Calcutta. The Royal Artillery Library at Woolwich. The Royal Observatory at Greenwich. The Observatory at Dublin. The Observatory at Armagh. The Observatory at the Cape of Good Hope. The Observatory at Madras. The Observatory at Paramatta. The Observatory at Edinburgh. Denmark. The Royal Society of Sciences at Copenhagen. The Royal Observatory at Altona. France. The Royal Academy of Sciences at Paris. The Royal Academy of Sciences at Toulouse. The Ecole des Mines at Paris. The Geographical Society at Paris. The Entomological Society of France. The Dépôt de la Marine, Paris. The Geological Society of France. The Jardin des Plantes, Paris. Germany. The University at Göttingen. The Cæsarean Academy of Naturalists at Bonn. The Observatory at Manheim. The Royal Academy of Sciences at Munich. Italy. The Institute of Sciences, Letters and Arts, at Milan. The Italian Society of Sciences at Modena. The Royal Academy of Sciences at Turin. Switzerland. The Société de Phys. et d'Hist. Nat. at Geneva. Belgium. The Royal Academy of Sciences at Brussels. Netherlands. The Royal Institute of Amsterdam. The Batavian Society of Experimental Philosophy at Rotterdam. Spain. The Royal Observatory at Cadiz. Portugal. The Royal Academy of Sciences at Lisbon. Prussia. The Royal Academy of Sciences at Berlin. Russia. The Imperial Academy of Sciences at St. Petersburg. The Imperial Observatory at Pulkowa. Sweden and Norway. The Royal Academy of Sciences at Stockholm. The Royal Society of Sciences at Drontheim. United States. The American Philosophical Society at Philadelphia. The American Academy of Sciences at Boston. The Library of Harvard College. The Observatory at Washington. The fifty Foreign Members of the Royal Society. A List of Public Institutions and Individuals, entitled to receive a copy of the Astronomical Observations made at the Royal Observatory at Greenwich, on making application for the same directly or through their respective agents, within two years of the date of publication. In the British Dominions. The Queen's Library. The Board of Ordnance. The Royal Society. The Savilian Library, Oxford. The Library of Trinity College, Cambridge. The University of Aberdeen. The University of St. Andrews. The University of Dublin. The University of Edinburgh. The University of Glasgow. The Observatory at Oxford. The Observatory at Cambridge. The Observatory at Dublin. The Observatory at Armagh. The Observatory at the Cape of Good Hope. The Observatory at Paramatta. The Observatory at Madras. The Royal Institution of Great Britain. The Royal Society, Edinburgh. The Observatory, Trevandrum, East Indies. The Astronomical Institution, Edinburgh. The President of the Royal Society. The Lowndes's Professor of Astronomy, Cambridge. The Plumian Professor of Astronomy, Cambridge. L. Holland, Esq., Lombard Street. Sir John William Lubbock, Bart., V.P. Captain W. H. Smyth, R.N., Chelsea. Sir James South, Observatory, Kensington. In Foreign Countries. The Royal Academy of Sciences at Berlin. The Royal Academy of Sciences at Paris. The Imperial Academy of Sciences at St. Petersburg. The Royal Academy of Sciences at Stockholm. The Royal Society of Sciences at Upsal. The Board of Longitude of France. The University of Göttingen. The University of Leyden. The Academy of Bologna. The American Academy of Sciences at Boston. The American Philosophical Society at Philadelphia. The Observatory at Altona. The Observatory at Berlin. The Observatory at Breslau. The Observatory at Brussels. The Observatory at Cadiz. The Observatory at Coimbra. The Observatory at Copenhagen. The Observatory at Dorpat. The Observatory at Helsingfors. The Observatory at Königsberg. The Observatory at Manheim. The Observatory at Marseilles. The Observatory at Milan. The Observatory at Munich. The Observatory at Palermo. The Observatory at Paris. The Observatory at Seeberg. The Observatory at Vienna. The Observatory at Tubingen. The Observatory at Turin. The Observatory at Wilna. The Dépôt de la Marine, Paris. The Bowdoin College, United States. The Library of Harvard College, The Waterville College, United States. List of Observatories, Institutions and Individuals, entitled to receive a Copy of the Magnetical and Meteorological Observations made at the Royal Observatory, Greenwich. ### Observatories - Altona . . . . . . . M. Schumacher. - Armagh . . . . . . Rev. Dr. Robinson. - Berlin . . . . . . J. F. Encke. - Bombay . . . . . . Dr. Buist. - Barnaul . . . . . . M. Prang, 1st. - Breslau . . . . . . Prof. Boguslawski. - Brussels . . . . . . A. Quetelet. - Cadiz . . . . . . M. Cerquero. - Cairo . . . . . . M. Lambert. - Cambridge . . . . Prof. Challis. - Cambridge, United States . . . . Prof. Lovering. - Cape of Good Hope . . . . T. Maclear, Esq. - Catherineburgh . . . . M. Rochkoff. - Christiania . . . . M. Hansteen. - Cincinnati . . . . Dr. Locke. - Copenhagen . . . . M. Oersted. - Dublin . . . . . . Sir W. R. Hamilton. - Gotha . . . . . . . - Hammerfest . . . . . - Heidelberg . . . . M. Tiedemann. - Helsingfors . . . . M. Nervander. - Hobarton . . . . Lieut. Kay, R.N. - Kasan . . . . . . M. Simonoff. - Kew . . . . . . Observatory. - Königsberg . . . . . - Kremsmünster . . . . Prof. Koller. - Leipsic . . . . . . Prof. Weber. - Madras . . . . . . T. G. Taylor, Esq. - Manheim . . . . . - Marburg . . . . . . Prof. Gerling. - Milan . . . . . . M. Carlini. - Munich . . . . . . Dr. Lamont. - Nertchinsk . . . . M. Prang, 2nd. - Nikolaieff . . . . Dr. Knorr. - Oxford . . . . . . M. J. Johnson, Esq. - Paris . . . . . . M. Arago. - Pekin . . . . . . M. Gachkévitche. - Prague . . . . . . M. Kreil. - Pulkowa . . . . . M. Struve. - St. Helena . . . . Lieut. Strange, R.A. - St. Petersburgh . . . . M. Kupffer. - Seeberg . . . . . . M. Hansen. - Singapore . . . . Lieut. C. M. Elliot. - Sitka . . . . . . Messrs. Homann and Ivanoff. - Stockholm . . . . . Prof. Selander. - Tefflis . . . . . . M. Philadelphine. - Toronto . . . . . . Captain Lefroy, R.A. - Trevandrum . . . . J. Caldecott, Esq. - Tubingen . . . . . - Upsal . . . . . . Prof. Svanberg. - Vienna . . . . . . C. L. von Littrow. - Warsaw . . . . . . Col. G. Du Plat (British Consul). - Washington . . . . Lt. Maury, U.S. Navy. - Wilna . . . . . . ### Institutions - Aberdeen . . . . . University. - Berlin . . . . . . Academy of Sciences. - Bologna . . . . . Academy. - Bonn . . . . . . University. - Boston . . . . . . Academy of Sciences. - Bowdoin College . . . . United States. - Bowditch Library . . . . United States. - Cambridge . . . . Trinity College, - Cherkow . . . . . University. - Convent of St. Bernard . . . . Switzerland. - Dorpat . . . . . . University. - Dublin . . . . . . University. - Edinburgh . . . . Observatory. - Edinburgh . . . . Royal Society. - Edinburgh . . . . University. - Glasgow . . . . . University. - Göttingen . . . . University. - Harvard College . . . . United States. - House of Lords, Library . . . . London. - House of Commons, Library . . . . " " - Kiew . . . . . . University. - King's College, Library . . . . London. - Leyden . . . . . . University. - Moscow . . . . . University. - Paris . . . . . . Academy of Sciences. - Paris . . . . . . Board of Longitude. - Paris . . . . . . Dépôt de la Marine. - Philadelphia . . . . Philosophical Society. - Queen's Library . . . . London. - Royal Cornwall Polytechnic Society . . . . Falmouth. - Royal Institution . . . . London. - Royal Society . . . . " " St. Andrews . . . . . University. St. Petersburgh . . . . Academy of Sciences. St. Petersburgh . . . . Geographical Society. Savilian Library . . . . Oxford. Stockholm . . . . . Academy of Sciences. Upsal . . . . . Society of Sciences. Waterville College . . United States. Individuals. Bache, Dr. A. D. . . . Washington. Birt, W. H., Esq. . . . London. Christie, S. H., Esq. . Woolwich. Colebrooke, Sir W. . New Brunswick. Demidoff, Prince Anatole de Florence. Dove, Prof. . . . Berlin. Erman, Dr. Adolph . Berlin. Fox, R. W., Esq. . Falmouth. Gauss, M. . . . Göttingen. Gilliss, Lt. J. M., U. S. Navy Washington. Harris, Sir W. Snow . Plymouth. Holland, L., Esq. . Lombard-street. Howard, Luke, Esq. . Tottenham. Humboldt, Baron . . Berlin. Kaemtz, M. . . Dorpat. Kupffer, A. T. . . St. Petersburgh. Lawson, Henry G., Esq. . Bath. Lloyd, Rev. Dr. . . . University, Dublin. Loomis, Prof. . . . New York. Lowndes Prof. of Astronomy Cambridge. Lubbock, Sir John W., Bart. London. Lütke, Vice-Admiral . St. Petersburgh. MacCullagh, James, Esq. . University, Dublin. Mahlmann, Prof. . . Berlin. Melvill, J. C., Esq. . East India House. Mentchikoff, Prince . St. Petersburgh. Phillips, John, Esq. . York. Plumian Prof. of Astronomy Cambridge. President of the Royal Society London. Quetelet, A. . . Brussels. Redfield, W. C., Esq. . New York. Reid, Lieutenant-Colonel . Barbadoes. Riddell, Capt., R.A. . Woolwich. Roget, P. M., M.D. . London. Sabine, Lieut.-Col., R.A. . Woolwich. Senftenberg, Baron von . Prague. Smyth, W. H., Captain R.N. London. South, Sir James . . " , " Wenchebach, Prof. . Utrecht. Wartmann, Elie . Lausanne. Wrangell, Vice-Admiral . St. Petersburgh. Younghusband, Capt. . Woolwich. ROYAL MEDALS. HER MAJESTY QUEEN VICTORIA, in restoring the Foundation of the Royal Medals, has been graciously pleased to approve the following regulations for the award of them: That the Royal Medals be given for such papers only as have been presented to the Royal Society, and inserted in their Transactions. That the triennial Cycle of subjects be the same as that hitherto in operation: viz. 1. Astronomy; Physiology, including the Natural History of Organized Beings. 2. Physics; Geology or Mineralogy. 3. Mathematics; Chemistry. That, in case no paper, coming within these stipulations, should be considered deserving of the Royal Medal, in any given year, the Council have the power of awarding such Medal to the author of any other paper on either of the several subjects forming the Cycle, that may have been presented to the Society and inserted in their Transactions; preference being given to the subjects of the year immediately preceding: the award being, in such case, subject to the approbation of Her Majesty. The Council propose to give one of the Royal Medals in the year 1847 for the most important unpublished paper in Mathematics, communicated to the Royal Society for insertion in their Transactions after the termination of the Session in June 1844, and prior to the termination of the Session in June 1847. The Council propose also to give one of the Royal Medals in the year 1847 for the most important unpublished paper in Chemistry, communicated to the Royal Society for insertion in their Transactions after the termination of the Session in June 1844, and prior to the termination of the Session in June 1847. The Council propose to give one of the Royal Medals in the year 1848 for the most important unpublished paper in Astronomy, communicated to the Royal Society for insertion in their Transactions after the termination of the Session in June 1845, and prior to the termination of the Session in June 1848. The Council propose also to give one of the Royal Medals in the year 1848 for the most important unpublished paper in Physiology, including the Natural History of Organized Beings, communicated to the Royal Society for insertion in their Transactions after the termination of the Session in June 1845, and prior to the termination of the Session in June 1848. The Council propose to give one of the Royal Medals in the year 1849 for the most important paper in Physics, communicated to the Royal Society after the termination of the Session in June 1845, and prior to the termination of the Session in June 1848, and printed in the Philosophical Transactions. The Council propose also to give one of the Royal Medals in the year 1849 for the most important paper in Geology or Mineralogy, communicated to the Royal Society after the termination of the Session in June 1845, and prior to the termination of the Session in June 1848, and printed in the Philosophical Transactions. The Council propose to give one of the Royal Medals in the year 1850 for the most important paper in Mathematics, communicated to the Royal Society after the termination of the Session in June 1846, and prior to the termination of the Session in June 1849, and printed in the Philosophical Transactions. The Council propose also to give one of the Royal Medals in the year 1850 for the most important paper in Chemistry, communicated to the Royal Society after the termination of the Session in June 1846, and prior to the termination of the Session in June 1849, and printed in the Philosophical Transactions. I. The Bakerian Lecture.—On certain Phenomena of Voltaic Ignition and the Decomposition of Water into its constituent Gases by Heat. By W. R. Grove, Esq., M.A., F.R.S. II. Supplementary Paper on certain Phenomena of Voltaic Ignition, and the Decomposition of Water into its Constituent Gases by Heat. By W. R. Grove, Esq., M.A., F.R.S. III. Microscopic Observations on the so-called Vesicular Vapours of Water, as existing in the Vapours of Steam, and in Clouds, &c. By A. Waller, Esq., M.D. Communicated by P. M. Roget, M.D., Sec. R.S. IV. Quelques recherches sur l'Arc Voltaique, et sur l'influence qu'exerce le Magnétisme soit sur cet arc soit sur les corps qui transmettent les Courants Electriques Discontinus. Researches on the Voltaic Arc, and on the influence which Magnetism exerts both on this Arc and on bodies transmitting interrupted Electric Currents. By M. Auguste De la Rive, Professor in the Academy of Geneva, Foreign Member of the Royal Society, Corresponding Member of the Academy of Sciences at Paris, &c. &c. V. On the Lunar Atmospheric Tide at St. Helena. By Lieut.-Colonel Edward Sabine, R.A., For. Sec. R.S. VI. On the Diurnal Variation of the Magnetic Declination at St. Helena. By Lieut.-Colonel Edward Sabine, R.A., For. Sec. R.S. VII. On the Automatic Registration of Magnetometers, and other Meteorological Instruments, by Photography. By Charles Brooke, M.B., F.R.C.S.E. Communicated by G. B. Airy, Esq., F.R.S., Astronomer Royal. VIII. On the Automatic Registration of Magnetometers, and other Meteorological Instruments, by Photography. Supplement. By Charles Brooke, M.B., F.R.C.S.E. Communicated by G. B. Airy, Esq., F.R.S., Astronomer Royal. IX. On the Proper Motion of the Solar System. By Thomas Galloway, Esq., M.A., F.R.S. X. On Photographic Self-registering Meteorological and Magnetical Instruments. By Francis Ronalds, Esq., F.R.S. ADJUDICATION of the Medals of the Royal Society for the year 1847 by the President and Council. The Copley Medal to Sir John Frederick William Herschel, Bart., F.R.S., for his work entitled "Results of Astronomical Observations made during the years 1834, 1835, 1836, 1837 and 1838, at the Cape of Good Hope; being a completion of a Telescopic Survey of the whole surface of the visible heavens, commenced in 1825." The Royal Medal in the department of Chemistry, to George Fownes, Esq., F.R.S., for his Papers entitled "An Account of the Artificial Formation of a Vegeto-alkali," and "On Benzoline, a new Organic Salt-base from Bitter Almond Oil," published in the Philosophical Transactions for 1845. No recommendation of the Royal Medal in the department of Mathematics having been received, it was awarded to William Robert Grove, Esq., F.R.S., for his Papers entitled "On the Gas Voltaic Battery.—Voltaic Action of Phosphorus, Sulphur and Hydro-carbons," and "On certain Phenomena of Voltaic Ignition and the Decomposition of Water into its constituent Gases by Heat," published in the Philosophical Transactions for 1845 and 1847. The Bakerian Lecture for 1847 was delivered by William Robert Grove, Esq., M.A., F.R.S., and is contained in his paper entitled "On certain Phenomena of Voltaic Ignition and the Decomposition of Water into its constituent Gases by Heat." CONTENTS. XI. On the Amount of the Radiation of Heat, at night, from the Earth, and from various bodies placed on or near the surface of the Earth. By James Glaisher, Esq., of the Royal Observatory at Greenwich. Communicated by G. B. Airy, Esq., F.R.S., Astronomer Royal, &c. . . . . . . page 119 XII. On the Cause of the Discrepancies observed by Mr. Baily with the Cavendish Apparatus for determining the mean density of the Earth. By George Whitehead Hearn, Esq., of the Royal Military College, Sandhurst. Communicated by Sir J. F. W. Herschel, Bart., F.R.S. . . . . . . . 217 XIII. Electro-Physiological Researches.—Fifth Series. Part I. Upon Induced Con- tractions. Part II. On the Phenomena elicited by the passage of the Current through the Nerves of a living Animal, or an Animal recently killed, according to the Direction of the Current. By Signor Carlo Matteucci, Professor in the University of Pisa, &c. &c. Communicated by Michael Faraday, Esq., F.R.S., &c. &c. . . . . . . . . . . . . . . . . . . 231 XIV. Electro-Physiological Researches.—Sixth Series. Laws of the Electric Discharge of the Torpedo and other Electric Fishes—Theory of the production of Electricity in these Animals. By Signor Carlo Matteucci, Professor in the University of Pisa, &c. &c. Communicated by Michael Faraday, Esq., F.R.S., &c. &c. 239 XV. Electro-Physiological Researches.—Seventh and last Series. Upon the relation between the intensity of the Electric Current, and that of the corresponding physiological effect. By Signor Carlo Matteucci, Professor in the University of Pisa, &c. &c. Communicated by Michael Faraday, Esq., F.R.S., &c. &c. 243 XVI. On the Value in Absolute Alcohol of Spirits of different Specific Gravities. By George Fownes, Esq., F.R.S., Professor of Practical Chemistry in University College, London . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 XVII. On different properties of Solar Radiation producing or preventing a deposit of Mercury on Silver Plates coated with Iodine, or its compounds with Bromine or Chlorine, modified by coloured Glass media and the Vapours of the Atmosphere. By A. Claudet, Esq. Communicated by Sir David Brewster, F.R.S., &c. &c. 253 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 APPENDIX. Presents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [1]