THE manufacture of chemicals by electrolysis is now sufficiently important to justify the appearance of a monograph dealing with the subject. The author has given a complete and up-to-date account of processes now in use, and it is hoped that the matter has been so presented as to indicate, to some extent, future developments. There are many signs that industrial chemists realise the importance of electrolysis in the manufacture of organic chemicals, and the author has endeavoured to portray clearly the present position of this branch of the subject.