EHRLICH, Paul, German medical scien tist : b. of Jewish parents at Strehlen, Silesia, 14 March 1854; d. Homburg, 20 Aug. 1915. He was educated at the universities of Breslau, Strassburg, Freiburg and Leipzig. After gradu ating in medicine in 1878 he began his researches into the relationship existing between scientific medicine and chemistry, experimenting on the effects of various chemicals upon living tissue. He first chose the aniline dyes, on account of their effects being visible when injected into animals. With these dyes and their derivatives his whole life's work was concerned and his most brilliant triumphs were gained through their employment. By staining the tubercle bacillus with dyes he found that certain of them possessed a peculiar affinity for this bacillus and this accorded with the view on which he based his whole philosophyŚ that of the spe cific affinity of particular chemical substances for particular tissues, more especially for the organisms which cause disease. He next dis covered a method of testing the potency of the anti-diphtheria serum by experimenting on Fumea-pigs, which made it possible to standard ize the serum and accurately measure the dosage. Ehrlich then found a dye called ((try
pan redD which cured, fatal trypanosome in fection in mice. A further series of experi ments resulted in his greatest discovery, that of salvarsan (q.v.) or 606, a specific drug with power to destroy the spirochrete pallida, the specific organism of syphilis. This epoch-mak ing discovery has been described as the most potent therapeutic weapon in existence. Ehrlich laid the foundation of modern hamatology and also performed some notable researches in con nection with cancer; he formed the theory ((that the growth of cancer depended on food stuffs? Almost every university and learned society throughout the world honored the great scientist; the Nobel Prize was divided between him and Metchnikoff (q.v.) in 1908; the number of his decorations conferred by monarchs and princes was greater than he professed to be able to remember. 'xHe opened new doors to the unlmown and left the world his debtor."