EXPERIMENTAL RESEARCHES 0. S. С. *. G. SURVEY LIBRARY AND IN ARCHIVES No.. > Skel, EL E OT RI MICHAEL FARADAY, D.C.L., F. R.S. FDLLERIAN PROFESSOR OF CHEMISTRT IN THE ROYAL INSTITUTION. CORRESPONDING MEMBER, ETC., OF THE ROYAL AND IMPERIAL ACADEMIES OF SCIENCE OF PARIS, PETERSBURQH, FLORENCE, COPENHAGEN, BERLIN, OOTTINGEN, MODENA STOCKHOLM PALERMO, ETC., ETC. Beprinted from the PHILOSOPHICAL TRANSACTIONS of 1831—1838. VOL. I. Facsimile-reprint. LONDON : EICHARD AND JOHN EDWARD TAYLOR, PRINTERS AND PUBLISHERS TO THE UNIVEKSITY OF LONDON, BED LION COUET, FLEET STBEJ LIBRARY 1 1839. N.O.A.A U S Depi of Commerce National Oceanic and Atmospheric Administration ERRATA NOTICE One or more conditions of the original document may affect the quality of the image, such as: Discolored pages Faded or light ink Binding intrudes into the text This has been co-operative project between the NOAA Central Library and the Climate Database Modernization Program, National Climate Data Center (NCDC). To view the original document contact the NOAA Central Library in Silver Spring, MD at (301) 713-2607 x 124 or [email protected]. HOV Services Imaging Contractor 12200 Kiln Court Beltsville, MD 20704-1387 January 05, 2010 This Book is the РгоэеЛу of the U.S. COAST Ai-ini.;!ftii;.r.-T|.::V/,:v r <-•-! l-.- : í :' d This Book is the Property of the U, S, COAST AND GEODETIC SURVEY, and must be carried on Book inventory if not. returned before the Expiration of th$ Calendar Year- PREFACE. I HAVE been induced by various circumstances to collect in One Volume the Fourteen Series of Experimental Ee- searches in Electricity, which have appeared in the Phi- losophical Transactions during1 the last seven years: the chief reason has been the desire to supply at a moderate price the whole of these papers, with an Index, to those who may desire to have them. The readers of the volume will, I hope, do me the justice to remember that it was not written as a mhole, but in parts; the earlier portions rarely having- any known relation at the time to those which might follow. If I had rewritten the work, I perhaps might have con- siderably varied the form, but should not have altered much of the real matter : it would not, however, then have been considered a faithful reprint or statement of the course and results of the whole investigation, which only I desired to supply. I may be allowed to express my great satisfaction at finding', that the different parts, written at intervals du- ring- seven years, harmonize so well as they do. There would have been nothing1 particular in this, if the parts had related only to matters well ascertained before any of them were written :—but as each professes to contain IV PREFACE. something1 of original discovery, or of correction of re- ceived views, it does surprise even my partiality, that they should have the degree of consistency and apparent general accuracy which they seem to me to present. I have made some alterations in the text, but they have been altogether of a typographical or grammatical character ; and even where greatest, have been intended to explain the sense, not to alter it. I have often added Notes at the bottom of the page, as to paragraphs 59, SCO, 43Ü, 021, .559, 655, 598, 657, 883, for the correction of errors, and also the purpose of illustration : but these are all distinguished from the Original Notes of the Re- searches by the date of Dec. 1838. The date of a scientific paper containing any preten- sions to discovery is frequently a matter of serious im- portance, and it is a great misfortune that there are many most valuable communications, essential to the history and progress of science, with respect to which this point cannot now be ascertained. This arises from the circumstance of the papers having no dates attached to them individually, and of the journals in which they appear having such as are inaccurate, i. e. dates of a period earlier than that of publication. I may refer to the note at the end of the First Series, as an illustration of the kind of confusion thus produced. These circum- stances have induced me to affix a date at the top of every other page, and I have thought myself justified in using that placed by the Secretary of the Eoyal Society on each paper as it was received. An author has no right, perhaps, to claim an earlier one, unless it has re- ceived confirmation by some public net or officer. PREFACE. Before concluding these lines I would beg1 leave to make a reference or two; first, to my own Papers on Electro-magnetic Rotations in the Quarterly Journal of Science, 1822. xii. 74. 186. 283. 416. and also to my Letter on Magneto-electric Induction in the Annales de Chimie, li. p. 404. These might, as to the matter, very properly have appeared in this volume, but they would have interfered with it as a simple reprint of the " Experi- mental Researches " of the Philosophical Transactions. Then I wish to refer, in relation to the Fourth Series on a new law of Electric Conduction, to Franklin's ex- periments on the non-conduction of ice, which have been very properly separated and set forth by Professor Bache, (Journal of the Franklin Institute, 1836. xvii. 183.). These, which I did not at all remember as to the extent of the effect, though they in no way anticipate the ex- pression of the law I state as to the general effect of li- quefaction on electrolytes, still should never be forgot- ten when speaking of that- law as applicable to the case of water. There are two papers which I am anxious to refer to, as corrections or criticisms of parts of the Experimental Researches. The first of these is one by Jacobi, (Philo- sophical Magazine, 1838. xiii. 401.) relative to the pos- sible production of a spark on completing the junction of the two metals of a single pair of plates (915.). It is an excellent paper, and though I have not repeated the experiments, the description of them convinces me that I must have been in error. The second is by that excellent philosopher, Marianini, (Memória delia Societa Italiana di Modena, xxi. 205), and is a critical and ex- VI PREFACE. perimental examination of Series viii, and of the question whether metallic contact is or is not productive of a part of the electricity of the voltaic pile. I see no reason as yet to alter the opinion I have given ; but the paper is so very valuable, comes to the question so directly, and the point itself is of such great importance, that I intend at the first opportunity renewing; the inquiry, and, if I can, rendering--the proofs either on the one side or the other undeniable to all. Other parts of these researches have received the ho- nor of critical attention from various philosophers, to all of whom I am obliged, and some of-whose corrections I have acknowledged in the foot notes. There are, no doubt, occasions on which I have not felt the force of the remarks, but time and the progress of science will best settle such cases ; and, although I cannot honestly say that I wish to be found in error, yet I do fervently hope that the progress of science in the hands of its many zealous present cultivators will be such, as by giving us new and other developments, and laws more and more general in their applications, will even make me think that what is written and illustrated in these experimental researches, belongs to the by-gone parts of science. MICHAEL FARADAY. Boyal Institution, March, 1839. CONTENTS. Far. Series I. §. 1. Induction of electric currents 6 §. 2. Evolution of electricity from magnetism ... 27 §. 3. New electrical state or condition of matter . 60 §. 4s. Explication of Arago's magnetic phenomena. 81 Series II. §. 6. Terrestrial magneto-electric induction 140 §. 6. Force anddirection of magneto-electric induc- tion generally 193 Series III. §. 7. Identity of electricities from different sources 265 i Voltaic electricity 268 : ii Ordinary electricity 284 iii Magneto-electricity 343 iv Thermo-electricity 349 v Animal electricity 351 §. 8. Relation by measure of common and voltaic electricity 361 Note respecting Ampere's inductive results after 379 Series IV. §. 9. New law of electric conduction 380 §. 10. On conducting power generally 418 Series V. §. 11. Electro-chemical decomposition 450 ^T 1. New conditions of electro-chemical de- composition 453 ЧГ 2. Influence of waterin such decomposition 472 4[ 3. Theory of electro-chemical decomposi- tion 477 Series VI. §. 12. Power of platina &c. to induce combination 664 Series VII. §. 11.* Electro-chemical decomposition continued (nomenclature) , 661 4] 4. Some general conditions of electro-che- mical decomposition 669 ЧГ 5. Volta-electrometer 704 ЧГ 6. Primary and secondary results 742 *P 7. Definite nature and extent of electro- chemical forces 783 Electro-chemical equivalents 822