ABSTRACT
The science of electricity presents some features which mark it with special characters as distinguished from other branches of knowledge. Electricity has also a special position with regard to its intimate connection with almost every other form of natural energy. Evolved by mechanical actions, by heat, by movements of magnets, and by chemical actions, it is capable in its turn of reproducing any of these. The inductive actions we have described take place through the air, which is a non-conductor, and such actions may be made to take place through any other non-conductor. Such a copper cast, or any article in copper having a perfectly clean surface, can be readily covered by a film of silver by means of a similar arrangement, where a solution of cyanide of potassium, in which some chloride of silver has been dissolved, is made to take the place of the sulphate of copper.
