Dr. Gay has covered his subject in thorough fashion and has discussed the problem of asthma in a well balanced way, with sound emphasis on the allergic aspects. There are systematic chapters on symptoms, diagnosis, etc., and the chapter on therapy exhausts every detail. There are numerous charts and illustrations, and the many case reports emphasize the points brought out in the text. The book carries all the authority which comes when one has worked personally on a subject for a long time.