Paul Ehrlich (1854–1915), a German chemist, was a pioneer in the field of applied organic chemistry. He worked initially on dyestuffs and staining methods for microscopic study of bacteria; and then, beginning in 1891, at the Koch Institute in Berlin, on the search for drugs that would be effective against some of the bacteria that had by then been identified as the specific causes of many diseases. Ehrlich's early work on antitoxins evolved into a systematic examination of many candidate chemicals that might be effective against Treponema pallidum, the spirochaete responsible for syphilis. At that time, syphilis was a common disease and a serious public health problem. This work was based on the observation that many chemicals exhibited selective affinity for specific organisms and tissues. In 1909, in collaboration with Sakahiro Hata, a Japanese colleague at the Koch Institute, he developed Salvarsan, an arsenical that killed the spirochaete without killing the patient—although it did have some toxic side effects. Ehrlich was awarded the Nobel Prize for medicine in 1908.
JOHN M. LAST
(SEE ALSO: Syphilis)