THE ART OF ELECTROLYTIC SEPARATION OF METALS, ETC. THEORETICAL AND PRACTICAL. G. GORE. PREFACE. THIS volume is written to supply entirely devoted to the Electrolytic Separation and Refining of Metals exists at present in any lan- guage those hitherto written on the subject of Electro- metallurgy are more or less devoted to electro- or the processes of coating articles with thin layers of gold, silver, copper, nickel, and other metals the mould- ing and copying of works of art, of printers type, of engraved wooden blocks, and metal plates, c., by electro-deposition. Much of the information hitherto published on the subject lies scattered about in short articles and frag- mentary accounts, in periodicals and books and state- ments, more or less inaccurate, have been made, owing to the writers not having had access to the manufac- tories the processes in which they have attempted to describe. M. Kiliani and others have observed the privacy with which electrolytic refining works are con- ducted he says that its effect has been to some extent to make people believe that the operations carried on are based upon discoveries known only to a few, and are surrounded by difficulties of a very special and complicated nature. He writes with the object of dissipating this wrong impression, and of convincing On the Electrolytic Refining of Copper, in the Berg und Hutten- mannische Zeitung, 1885. all those interested in the subject, that whatever is done inside these works can be done by anybody who gives a little attention and study to the subject, the only secrets being slight and immaterial details of practice. The probable explanation of this is, that each electro- refiner, in consequence of being imperfectly acquainted with the literature of the subject, and of how his fellow- refiners were working, has been obliged to ascertain by means of experiments in his own works the practical details of the process and has thus independently arrived at the same general plan of operating as other refiners, whilst considering his own method a secret. The author of the present book, having been kindly electro-refiners of permitted by some of the largest copper and makers of electro-metallurgical dynamos in this country, to unreservedly inspect their manufactories, processes, and dynamo-electric machines, is thereby better enabled to avoid inaccurate statements. At the same time, whilst being at liberty to publish all information already open respecting the general processes employed by electro-refiners of metal, he carefully avoids making known any private communi- cations. His object is not to describe the arrangements employed in particular works, but only to supply such information as will be useful to students, and to those who are engaged in practically establishing and working electrolytic processes. Manufacturers secrets nearly always leak out, and the idea that any of importance remain relating to this subject is an illusion. A perusal of this book will show that whilst all the methods of working the electrolytic process employed in different works are substantially the same, and are based upon and conform to well-known principles of