Clara Immerwahr (1870-1915), German chemist. Immerwahr was the first woman to gain a PhD in Chemistry from a German university (1900). She was a very capable scientist and continued to work as a laboratory assistant after marrying Fritz Haber in 1901. However, she gave up her post to become a housewife after her first child, Hermann, was born in 1902. Immerwahr believed that science should only be used for constructive purposes and she was greatly disturbed by her husband's interest in chemical warfare. His direct involvement in the first large scale release of chlorine gas at Ypres, France on 22 April 1915 led to Immerwahr committing suicide ten days later.