The recent remarkable advances in the physiology of respiration have been largely based on observations made on man.1 This fact, coupled with their simplicity and ease of performance, fits these experiments to fill a widely felt pedagogic need. In the training of medical students heretofore, experiments on animals under more or less unnatural conditions have predominated. On man, who is properly the chief interest of the future physician, relatively little has been attempted. Indeed, it is not the least of the contributions which recent advances in the field of respiration have made that they have shown that, given the ingenuity to devise proper experiments, man himself, the normal healthy subject as well as the patient exhibiting functional disturbances, becomes a more profitable Versuchstier than dog, rabbit or frog.
The development of the art of conceiving experiments suitable for performance on man, and a more general recognition of the fact