IN this work we welcome a valuable contribution to the scanty English literature of a subject of vast and constantly growing importance. A great increase of interest in biological chemistry and a consequent rapid development of the subject along almost innumerable lines have been among the most noticeable features in the history of chemistry during the last ten or fifteen years. Stimulated by the brilliant successes of Fischer and the important researches of Buchner, many workers have devoted themselves to the study of biochemical problems, and especially to the investigation of enzyme action. Accompanying this scientific movement, and no doubt in part responsible for it, there has been a widespread introduction of biological methods into the routine experience alike of the industrial and analytical chemist. The subjects of agricultural and dairy chemistry, water analysis and sewage disposal, to say nothing of the advance in the old-established fermentation industries, at once suggest themselves as instances of this tendency, and an audience has thus been created anxious for authoritative information on the principles underlying the application of biology to all these questions. An Introduction to Bacteriological and Enzyme Chemistry. By Dr. G. J. Fowler. Pp. viii + 328. (London: Edward Arnold, n.d.) Price 7s. 6d. net.