The hypodermic use of medicaments calculated to make a deep and rapid impression on the blood and the blood-making organs and to combat certain infections is not new. For many years, in the treatment of secondary and tertiary syphilis, it has been the custom, originally amongst the Latins, and more latterly amongst American clinicians, to administer mercury subcutaneously. For rapidity of effect this method of giving the drug is without a peer. Of late years considerable interest has been directed toward the administration in this manner of drugs whose purpose was to overcome diseases essential to the blood itself, blood dyscrasias and blood deterioration dependent on systemic or local infection or toxemia. The old adage "remove the cause" as the primary act to be accomplished has, with reference to the treatment of many diseases, become stale and trite, and, in a vast number of instances, is more easily said than