The treatment of cardiovascular disorders by a thirst cure was well known in the Middle Ages, but had fallen into desuetude until it was revived by Oertel a quarter of a century ago. His contention that in cases of failing compensation there exists a condition of "hydraemic plethora" was evidently advanced without sufficient authority, for subsequent observers have failed to verify it, or even to find hydraemia, unless where such a complication as malnutrition or inanition was present. All that is known is that in cases of insufficient cardiac action there is a reversal of the normal blood distribution, the veins containing more and the arteries less than normal. But such statements hardly affect the situation, because it is proved by actual practice that limitation of the ingestion of liquids is of great value in cases of all kinds where the cardiac muscle is labouring at a disadvantage; and although this procedure does not obviate the necessity for the use of such remedies as digitalis, it frequently enables them to exert their physiological action, where this had been abrogated by reason of the heart being incapable of overcoming the resistance of an excessive volume of blood. A somewhat similar regimen to that advocated in cases of atonic dilatation of the stomach is found of great value in heart disease, and if at the same time the diet be salt-free, under the influence of appropriate diuretics the kidneys will act freely, oedema be relieved, and the case make satisfactory progress, when such a termination had been despaired of before the change of diet had been instituted.

By restriction of the consumption of liquid to less than 30 ounces daily Haig declares that he has been able to lower the blood-pressure by 20 to 30 mm. of mercury, with relief of the symptoms of hypertension, viz., headache, epilepsy, and depression.