THERAPEUTICS

isolated from the blood. Diphtheria is merely a toxaemia, enteric is largely a bacteraemia. Numerous investigations have shown that the bacterial agent in the disease may show wide variations in its biological character and in the quality of the agglutinating substance which it ?elaborates in the system. It was at first hoped that the agglutinating properties of the serum would afford a ready means of distinguishing between the typhoid organism and the colon bacillus, but it is now known that typhoid serum agglutinates most colon cultures, sometimes to a very marked degree. Then, again, bacteria intermediate in type between the typhosus and the colon bacillus are capable of giving rise to irregular forms of typhoid. A further distinction between diphtheria and enteric lies in the fact that the diphtheria toxine is highly diffusible, being readily soluble in water, while typho-toxine is only slowly soluble in water, and does not possess the digestive properties of diphtheria toxine. Typho-toxine kills slowly and does not produce the specific lesions of typhoid. It has further been shown that procedures which render animals immune to infection by the typhoid bacillus are incapable of protecting them against the products or macerated bodies of the