The peculiar pathologic phenomena, such as urticaria and articular pains, which may occur after the introduction of foreign serum of any kind, have been grouped together under the convenient name of the serum disease. We recently3 discussed the theories as to the causation of this remarkable condition. Many efforts have been made to prevent this disease, which constitutes an annoying disadvantage incidental to serum therapy of all kinds.
Some ten years ago Wright4 showed that as the symptoms of the serum disease develop there occurs a diminution in the coagulability of the blood and that calcium salts appeared to have a preventive effect. Hence he suggested that calcium salts should be administered in order to forestall urticaria, etc., and that they should be given also to remove more rapidly these troubles when they have supervened.
Recently the good effects of the calcium salts in these directions, especially the