The Chemotherapy of Sulphon-Amides.

THE chemotherapy of bacterial diseases is a medical innovation of the last four years only. In the case of the protozoal infections, on the other hand, this form of treatment is comparatively ancient. The discovery of the effect of quinine in malaria dates from the seventeenth century, and mercury was used in syphilis in very early times. In I9IO Ehrlich and Hata published the discovery of the synthetic organic arsenical, Arsphenamine, and subsequently Neoarsphenamine, and their therapeutic effects in spirochaetal infections. These were the first successful synthetic substances to be used in chemotherapy, and they have led to a most fruitful co-operation between the chemist and biologist which has given us several very important remedies. The bacterial diseases had been considered to be resistant to this type of therapy. It was thought that these infecting agents were too primitive in structure to be influenced by any drug which was not noxious to the host; the only method of treating them was by the administration of sera, which combined with and neutralised the toxic products elaborated by the bacteria but did not directly influence their powers of multiplication. The fact that the chemotherapy of protozoal diseases is so ancient may be attributed to the occurrence of quinine in the vegetable kingdom. Had there been a mineral or vegetable which contained sulphanilamide in some therapeutically active form we might have benefited by the potent action of this drug for the last 300 years.