Charles Dawson, a long-time professor of chemistry at Columbia University, died in May in Wolfeboro, New Hampshire. Dr. Dawson taught at Columbia from 1939 until his retirement in 1979. During his teaching career it is estimated that he taught over 10,000 students of chemistry. Dawson received a B.Sc. in 1933, a M.Sc. in chemistry in 1935, and an honorary doctorate of science in 1953, all from the University of New Hampshire. He received a doctorate in 1938 and an honorary doctorate of science in 1988, both from Columbia University. Dawson played the leading role in the discovery of the toxic compounds in poison ivy (Rhus toxicodendron). In 1940, he and Dr. David Wasserman, then a graduate student, began to carry out experiments involving poison ivy. They collected 80 pounds of poison ivy bark, from which they extracted two teaspoons of the poisonous oil. They began work on developing methods of synthesizing compounds similar to those found in the oil. In 1948, the compound they developed was announced and subsequently tested on volunteers at the New York Post-graduate Medical School. By 1953, Dawson and his research students had isolated the toxic agent in the sap and had broken it down into four parts. With researchers from the National Institutes of Health, Dawson set about trying to discover a treatment or vaccine based on the least toxic of the four. In 1955, tests carried out at the University of Pennsylvania on such a vaccine were reported to be successful. Thousands of volunteers had submitted to a series of injections intended to desensitize them to poison ivy. Marketed in 1956, the vaccine was supplanted by steroid-based anti-inflammatory ointments.

Article copyright American Botanical Council.

~~~~~~~~

By Barbara A. Johnston