In a previous communication,1 which was concerned chiefly with the total energy transformations in tuberculosis, a few experiments were given dealing with the nitrogen minimum in this disease. It was thought to be desirable to extend these observations so as to include data, not only regarding the minimal level of protein metabolism, but as far as possible to throw light on the optimal quantity with which to supply patients suffering from pulmonary tuberculosis. Because of its intimate bearing on the problem of finding the optimal protein requirement for such patients, the knowledge acquired concerning the basal metabolism was supplemented by experiments on the effect of protein food upon the heat production. Further experiments were made2 in which the action of all the foodstuffs was studied, not only on the metabolism, but on the pulmonary ventilation as well. Studies of the protein metabolism in this disease, made up to 1903, have