"Hypotension when found persistently in individuals or families or classes living under certain unhygienic conditions should put us on our guard against at least a predisposition to tuberculosis. Most unhygienic conditions, overwork, undernourishment and insufficient air, are of themselves causes of a diminished resistance, and it seems likely that a failure of normal cardiovascular response to exercise or change of position may be found to indicate this stage of susceptibility, especially to tuberculous infection. "... Hypotension, when it is present in tuberculosis, increases with an extension of the process. Recovery from hypotension accompanies arrest or improvement. Return to normal pressure is commonly found in those who are cured. Continuation of hypotension seems never to accompany improvement. Prognosis can as safely be based on the alteration in the blood pressure as on changes in the pulse or temperature...." There are a few drugs which lower the blood pressure, but, as a rule, their effects are more or less transitory. We know of no drug, unless it be iodide of potassium, which has the property of causing changes in the blood (decrease in viscosity?), which tends to reduce the blood pressure when it is excessive. This drug fails us many times. SOME DRUGS WHICH INFLUENCE THE BLOOD PRESSURE =Pressure Raisers= Adrenalin, when injected directly into a vein or deep into the muscles. The action is transitory. Caffeine, preferably in the form of caffeine-sodium-benzoate. A good drug. Strychnine, which does not act directly but seemingly through the higher centers. Ergot, somewhat uncertain. Nicotine, not used therapeutically. Camphor, used in sterile olive oil and injected deeply into the muscles. Digitalis, when the cardiac tone is low and decompensation is present. Its action is prolonged but slow. Injections of the infundibular portion of the pituitary body. Not in use clinically. =Pressure Depressors= Nitroglycerine and amyl nitrite, action transitory but rapid. Sodium nitrite and erythrol tetranitrate. Action somewhat more prolonged. Aconite, veratrum viride, chloral, etc. These depress the heart. Purgatives, drastic and hydragogue. Potassium and sodium iodide may lower blood pressure. When they do, the action is prolonged. Diuretin and theocin-sodium-acetate. =Venous Pressure= Comparatively little work has been done upon the determination of the pressure in the veins in man. It is conceivable that this procedure may, at times, be of great value. A number of attempts have been made to measure the venous pressure by compressing the arm veins and noting on a manometer the force necessary to obliterate the vein. As the pressure is so slight, water is used instead of mercury, and readings have been given in centimeters of water.