Rachel Fuller Brown, with her associate Elizabeth Hazen, developed the first effective antibiotic against fungal disease in humans--the most important biomedical breakthrough since the discovery of penicillin two decades earlier. The antibiotic, called nystatin, has cured sufferers of life-threatening fungal infections, vaginal yeast infections, and athlete's foot. Nystatin earned more than $13 million in royalties during Brown's lifetime, which she and Hazen dedicated to scientific research.

Brown was born in Springfield, Massachusetts, on November 23, 1898, to Annie Fuller and George Hamilton Brown. Her father, a real estate and insurance agent, moved the family to Webster Groves, Missouri, where she attended grammar school. In 1912, her father left the family. Brown and her younger brother returned to Springfield with their mother, who worked to support them. When Brown graduated from high school, a wealthy friend of the family financed her attendance at Mount Holyoke College in Massachusetts.

At Mount Holyoke, Brown was...