EX-PROFESSOR IN THE ACADEMY OF GENEVA; AND HONORARY DOCTOR FOREIGN MEMBER OF THE ROYAL SOCIETY OF LONDON: CORRESPONDING MEMBER of the ACADEMY OF SCIENCES OF PARIS; MEMBER OF THE SOCIETIES OF ARTS AND OF ETC. ETC. TRANSLATED FOR THE AUTHOR BY CHARLES V. WALKER, F. R. S. IN THREE VOLUMES. VOL. II. LONDON: LONGMAN, BROWN, GREEN, AND LONGMANS. 1856. The Author reserves to himself the right of translating this Work. IT is three years since the First Volume of the Treatise on Electricity in Theory and Practice appeared. This long interval, which has elapsed between the publication of these two volumes, is due to the desire, that I have entertained, of not allowing the Second to appear, until after my having succeeded in giving a satisfactory theory of the voltaic pile. I hope to have solved this difficult and contested question, in a manner that will be accepted by all who have turned their attention to it. I have also to justify myself on another point; it is the necessity in which I am placed of publishing a Supplementary Volume. The very great development, that I have felt it necessary to give to the subjects discussed in this volume, on account of their importance, and of the very great numbers of works of which they have been the object, have rendered it impossible for me to include in it the Applications of Electricity. I have therefore determined to devote to them a supplementary volume, which will enable me to give to them the extension, which they merit. This change in my original plan has led me to introduce a second change, namely, the addition of a new Part to the Six of which the Treatise should have consisted. This part, which will be the Sirth, the applications becoming the |