Recent work on the part of a number of observers has thoroughly established the importance of a knowledge of venous pressure in certain clinical states and has extended and amplified its significance in the dynamics of the failing heart. The main conclusions from these observations1may be briefly stated as follows: 1. The venous pressure measured in a peripheral vein placed at the level of the right auricle, with the subject in a recumbent or semirecumbent position at body rest, does not exceed 110 mm. of water unless the heart is incompetent and is failing to meet fully the demands for circulatory maintenance. This appears to be true in all clinical states other than cardiac failure, the only exceptions being some localized obstruction to venous return. 2. Venous pressure in cardiac incompetence varies from the upper normal level to 300 mm. of water or more. The extent of the