Hypotension is one of the indefinite problems of medicine. Few articles have been written on the subject, compared to the large number on hypertension. The studies thus far have been far more pharmacologic, experimental and surgical than clinical, and directly related to internal medicine. This is shown by the researches of Crile,1Cannon2and Rich,3as compared with the paucity of researches by internists. Huchard and Mougeot,4Grasset and Calmette,5Muenzer,6Knapp,7Martinet8and Reynaud,9in Europe, and Piersol,10Emerson,11Lawrence,12McCrae13and Goodman,14in America, have discussed the subject from various points of view. Faught15says that "unfortunately the literature almost entirely lacks exhaustive studies of low blood systolic pressures," and Goepp16says that "a little attention has been given to the subject, at least in its relation to chronic disease." Sir Clifford