The symptoms of tetany occur in a number of widely differing conditions, such as disease of the stomach, overdosage with sodium bicarbonate, prolonged hyperpnea, absence of the parathyroid glands, and in infants as a clinical entity often associated with rickets. Recently there has been a considerable amount of research into the physiologic phenomena underlying the increased irritability of nervous and muscular tissues in these conditions, and various theories as to its etiology have been advanced. The chief of these are that it is due to a disturbance of the acid-base equilibrium in the body and to a disturbance of the calcium metabolism.1 Acid-base disturbance, consisting of an increase in the ratio of sodium bicarbonate to carbonic acid, is found in overdosage with sodium bicarbonate, in prolonged hyperpnea and in pyloric obstruction. The uniform hydrogen ion concentration of the body fluids is largely dependent on the maintenance of a constant