Having arrived at the cause of his periodic headaches, and having formed the opinion that in order to prevent them the formation of uric acid must be diminished, and the high alkalinity of the blood maintained, what was the process of cure adopted? A change of diet. And it is for this reason that Dr. Haig's researches on a rather abstruse subject are particularly interesting to us. His object was to decrease the formation of urea and uric acid, and to keep up the alkalinity of the blood, so that the uric acid formed should be held in solution and steadily excreted daily by the kidneys, instead of being driven into the joints and tissues. An animal diet increases acidity, a vegetable diet diminishes it. Dr. Haig succeeded in curing his headaches by reducing the intake of nitrogenous food and by putting himself on a vegetable diet. In this way the excretion of urea was decreased from an average of 500 grains to 300 grains a day, and of uric acid from 16 grains to 9 grains. The alkalinity of the blood was maintained, the old stores of urates were washed out of the tissues, and when the exact balance was arrived at, and the uric acid daily produced was daily excreted, the headaches ceased.