In this book the author studies the acid-base equilibrium, both normal and pathologic. The book is divided into three parts, which deal respectively with the normal acid-base equilibrium from biochemical and physiologic angles, the various types of acidosis and alkalosis and their pathogenesis, and the treatment of the various types of acidosis and alkalosis which are observed by practitioners of internal medicine, clinical surgery, pediatrics, urology, gynecology and several other medical specialties. Special reference is made to the treatment of grave conditions caused by the rupture of the acid-base equilibrium which have to be rapidly controlled by introduction, in the blood, of a radical the amount of which is insufficient in the blood plasma, such as, for instance, rechloridation in alkalosis from hypochloremia and administration of injections of sodium chloride solutions in the course of Addison's disease and of calcium in hypocalcemia in tetany. The subject, on the whole, is