Copper, in view of its reputed germicidal action and its relatively low degree of toxicity for higher mammals, would seem to have possibilities as yet unrealized in the therapeutics of infectious diseases. There is considerable literature of one sort and another on the use of copper salts for the treatment of infectious diseases, but most of it is sporadic in character, and apparently the results described have not been such as to lead to any very general adoption of copper in chemical therapeutics. In recent years perhaps the most satisfactory results have been obtained with copper in treatment of diseases due to higher fungi, such as oidiomycosis, actinomycosis and sporotrichosis, as recommended especially by Bevan. With the introduction of the principles of chemotherapy by Ehrlich, it seemed possible to us that organic compounds of copper might be successfully developed which would have distinct advantages in the treatment of bacterial and