Charlotte Auerbach

Charlotte Auerbach was a geneticist whose early-1940s experiments with William Robson established mustard gas as the first known chemical mutagen. Their discovery connected chemical exposure to permanent chromosome abnormalities and mutations, extending the understanding of how heredity could be altered beyond the effects of radiation.

Research with Mustard Gas

Working at the University of Edinburgh, Auerbach and Robson found that mustard gas produced permanent chromosome abnormalities. These changes could not be distinguished from abnormalities induced by radiation, placing the chemical effects alongside a known consequence of physical exposure.

Evidence from Fruit Flies

The researchers tested mustard gas on fruit flies, the same organism Hermann J. Muller had used in his original work with X-rays. The experiments showed that mustard gas produced mutations as well as chromosome abnormalities, linking the visible chromosomal effects to changes in inherited material.

Significance

The discovery identified the first chemical mutagen. It also opened a wider field of concern: mustard gas was followed by a long list of chemicals known to alter genetic material in plants and animals. Auerbach and Robson’s work thus helped establish that chemicals could change the course of heredity, a question the book develops through its account of how such changes occur.