Since World War II, largely because of experiences gained in tropical areas where many service people were incapacitated by diseases involving the sweat glands, there has been an increased interest in the mechanism of sweating. The authors reported on their observations in 1950 and 1951 at meetings of the American Academy of Dermatology, and, as a result of these discussions, this book was compiled. The result is a work that is as up to date as a book can be. The material is divided into three parts. The first, dealing with investigative approaches, describes briefly the various methods of assaying perspiration: noting changes in body weight, the use of special collecting chambers for making hygrometric measurements, temperature differential, infrared ray absorption, various chemical reactions, measurements of electrical resistance, and color indicator methods. The physiological data obtained by these various techniques are then discussed, with consideration given to differences observed in