Contributions of the Instituto Nacional de Cardiología.
—Productive investigations in several fields have been conducted recently at the Instituto Nacional de Cardiología.
—A digitalis-like substance, thevetoidin, has been isolated from a Mexican species of Thevetia (Thevetia gaumeri). Thevetoidin is a mixture of crystalline substances containing two types of polysaccharides, a small amount of a quaternary ammonium base and a pure glycoside, which is in the process of being identified. Thevetoidin has a rapid action, similar to that of strophanthin.
—A new method has been developed for the study of coronary flow in the isolated heart which permits more accurate analysis of the factors that determine coronary output.
—Institute workers for the first time have recorded the electrical phenomena within the mass of the septal wall, not merely septal surface phenomena. This has been effected by the use of simultaneously recovering electrodes placed at various depths within the