A Manual of the Alkali Trade. By John Lomas. (Crosby
Lock- wood and Co.)—This is a work of thoroughly practical character. It discusses all the mechanical details, the planning and the working of a chemical factory devoted to the production of the chief compounds
usually turned out from an "alkali works." The volume does not contain, as its title seems to imply, an account of the trade or com- merce in alkali, but it is a book by a chemical manufacturer on the manufacture of chemicals. Oil of vitriol, soda, caustic soda, and bleaching-powder are the products discussed most fully in this manual. What with the working plans and drawings here given (some 232 in number), and the clear descriptions in the text, the arrangement and construction of alkali works, according to the best and most modern plans, ought to be readily understood. The chemical theory of the various operations has been put on one side by Mr. Lomas ; but we happily possess, in Dr. E. Lunge's exhaustive treatise, now being published in an English form, a manual which treats the chemical side of this important industry with great care and com- pleteness, and at the same time by no means neglects its engineering or mechanical aspect.