It is remarkable that a process so apparent as the circulation of the blood could have remained undiscovered through so many centuries during which there was an accumulation of knowledge of other more complex phenomena. If one only contemplates the vast number of opportunities which were presented for the discovery of the circulation of the blood and recalls the simplicity of the experiments of William Harvey, one is amazed that this discovery should have been deferred so long. It would seem as if a sort of mysticism always assigned to the cardiovascular mechanism had prevented an appreciation of its simple realities. Discussions of the problems of the circulation of the extremities still contain many vague ideas and few definite terms. It would seem worth while, therefore, to discuss some therapeutic measure applicable to disease of the circulation of the extremities with the object in view of tracing its historical development