The science of electrochemistry has come to have a far wider range of application, than formerly. A comparatively short time ago it comprised little more than methods of bringing about chemical reactions by means of electricity, and the utilization of chemical affinity for the production of an electric current. It has now become one of our most important aids in the investigation of some of the fundamental problems of general chemistry. The measurement of electromotive forces is the safest, and oftentimes the only, means of determining the chemical force with which reactions take place; conductivity measurements have given us an insight into the nature of solutions; electrochemistry has given rise to one of the most fruitful of the modern chemical theories, the theory of electrolytic dissociation. In practical as well as theoretical lines electrochemistry has been of immense value. Aside from the fact that many substances, such as the alkali metals, aluminium, magnesiumAbout the...