This whole subject has been very carefully studied by Dr. Alexander Haig, and the results of his inquiry are embodied in a book called Uric Acid as a Factor in the Causation of Disease. Dr. Haig was led to study this subject by an extremely severe and periodic headache from which he suffered almost every week, and which, from its painful violence and incapacitating character, threatened to cripple or cut short his career. Seeking its cause in order to accomplish its cure, he began to carefully examine the excretions of the body, and he arrived at the following interesting results. A headache occurred when there was an excess of excretion of uric acid following on a period when there had been a diminished excretion. Uric acid was excreted in excess when the urine was increasingly acid, and presumably, therefore, when the alkalinity of the blood was high. The excretion of uric acid corresponded with the severe headache, and, consequently, with the increased alkalinity of the blood and the increased acidity of the urine. Now what are the conditions which alter the alkalinity of the blood and the solubility of uric acid and the consequent excretion of the latter by the kidney? Cold decreases the alkalinity of the blood, and drives the uric acid into the joints and tissues; warmth and acid perspiration increase alkalinity, and the uric acid is then washed out of the joints and tissues into the blood; good dinners and generous wines decrease alkalinity, which is followed by a reaction and falling acidity. Dr. Haig found that by administering an acid to himself he could drive away his headache, by, in fact, driving the uric acid circulating in the blood into the joints and producing pain and pricking in these; or he could bring on the headache at will by giving himself a dose of alkali, when the uric acid deposited in the joints and tissues was washed out of them into the blood. It was the presence of an excess of uric acid or urates in the blood, he therefore argued, which caused the headache. He contends that what our forefathers called " phlegm and humours," what the unscientific call " bile," and what the doctors label gout or rheumatism, are all manifestations of the same condition, namely, an excess of uric acid in the system.