In some experiments to determine the changes upon the blood pressure induced by hot and cold applications on and within the abdomen, Hammett, Tice and Larson found that heat applied to the outside of the abdomen raises the blood pressure. The application of cold produces no change. Either hot or cold saline introduced within the abdomen causes a fall in blood pressure. Experimentally, certain drugs such as adrenalin, barium chloride, nicotine, digitalis, strophanthus and the infundibular portion of the pituitary body known as pituitrin raise the maximum pressure. In the clinic it is difficult to conclude always whether the drug alone is responsible for rise in maximum pressure. Adrenalin given intravenously will raise the pressure. So will digitalis and strophanthus. I have watched the maximum pressure rise within three minutes following an intravenous injection of gr. 1/100 (0.0006 gm.) strophanthin 20 mm. of Hg: I have seen the subcutaneous injection of 10 minims of adrenalin repeated several times daily for six months fail to have the least effect on the blood pressure picture. Elevation of the foot of the bed about nine inches proved so efficacious in steadying failing hearts in acute infectious diseases, particularly typhoid, that a study was made of the effect upon blood pressure. Many observations were made, but no instrumental proof of rise in blood pressure could be adduced. Exercise always raises blood pressure, the maximum much more than the minimum. In athletes the minimum pressure may actually fall, the maximum rise so that a greater volume output results from the greater pulse pressure. Shock and hemorrhage lower it. Hemorrhage lowers also the pulse pressure, and it may be possible to prognosticate internal hemorrhage by frequent estimations of the systolic and diastolic pressures (Wiggers). Compression of the superior mesenteric artery or the celiac axis in dogs raises the blood pressure measured in the carotid artery for a period of at least an hour. This seems to be dependent on purely mechanical causes, and is not a reflex vasomotor phenomenon. (Longcope and McClintock.) Experimentally blood pressure can be increased by direct compression of the brain as Cushing has shown. It was thought at one time that in man the same effect would result from tumor of the brain or especially from subdural or extradural hemorrhage following head injuries. This, however, is not the case. No information of great value can be obtained by the measurement of blood pressure in these states. We do know that too high and too prolonged compression of the medulla brings about exhaustion of the cardiac center accompanied with rapid pulse, low pressure and eventual death. =Hypertension=