Chemotherapy (Ehrlich)

“The movement from synthetic dyestuff to pharmaceuticals to chemotherapy to bacterial chemotherapy may be regarded as a series of steps in the diversification of an industrial enterprise and its research establishment. Continuity from dyestuff chemistry was expressed in personnel, in concepts and methods, and in the use of specific products. Hörlein, Mietzsch and Klarer [Bayer/IG Farben] were trained in dyestuffs chemistry and practiced it before moving to pharmaceuticals. On its chemical side, chemotherapeutic research involved methods of synthesis and concepts of specificity and variability taken over from dyestuffs chemistry. Hörlein drew a direct analogy between the natural/synthetic dichotomy in dyestuffs and the natural/synthetic dichotomy in medicinal substances. The azo dyes were tried as medicine, and one of them became Prontosil” (Lesch III, 65).