Harold Clarence Ernst (July 31, 1856 - September 7, 1922), physician and pioneering American bacteriologist, was born in Cincinnati, Ohio, to Andrew Ernst, a horticulturalist and arboriculturist, and Sarah H. Otis, an abolitionist and early women’s suffragist. His father and paternal grandfather, John Zacharias Ernst, a political leader in Hanover, fled Germany in 1804 to escape Napoleonic rule; his mother descended from the Revolutionary era Massachusetts politician and defender of the colonists’ rights, James Otis, who graduated Harvard aged 18 in 1743. In 1872, Ernst left Cincinnati for Cambridge, Massachusetts, where he enrolled at Harvard College. 96

Ernst was pitcher on the celebrated Harvard “baseball nine” of the mid 1870s; he was recognized for introducing curved ball pitching to the college game and the speed of his delivery prompted the invention of the catcher’s mask. He graduated with a bachelor's degree from the College in 1876 and with an M.D. from Harvard Medical School in 1880. There he was taught by William Sturgis Bigelow, who had studied with Louis Pasteur in Paris and introduced Ernst to the new field of bacteriology. After graduating, he became a house officer at the Rhode Island Hospital. In 1884, he received his master’s degree in bacteriology from Harvard and joined the Harvard laboratory as a demonstrator of bacteriology, a position he held until 1889 when he was made instructor.

In 1891, he was appointed assistant professor of bacteriology and in 1895 full professor, fundamentally shaping this nascent department until his death in 1922. In his time leading the department of bacteriology, Ernst persuaded the city of Boston to establish a bacteriological laboratory that achieved great advances in the detection and prevention of diphtheria, one of the first laboratories to do such work in the country. The lectures he delivered as a member of the staff of Harvard Medical School were the first in the United States on bacteriology as a part of regular instruction to medical students. In 1896, Ernst authored “Infectiousness of Milk,” and that same year he became editor of the Journal of Medical Research. He went on to author “Infection and Immunity” in 1898 and “Animal Experimentation” in 1902, among many other articles in scientific journals and medical periodicals published throughout his career. His work led to the widespread sterilization of milk for infant feeding, and he was the first to advise the use of dry sterilized surgical dressings.

In 1900, Dr. Ernst joined the staff of the Cuban Summer School as a Lecturer on Applied Bacteriology. He delivered his lectures in English with the help of Frank C. Menocal, the program’s interpreter for bacteriology.

In 1906, Ernst was appointed a member of the new standing committee on Medical Education of the Massachusetts Medical Society - an important committee organized at the request of the American Medical Association. He remained chairman of the committee until 1919. In this time, Ernst offered his services to the war effort and was in charge of laboratory work of the Northeastern Division with the rank of Major. He held a number of other prestigious leadership positions in scientific and medical societies, including serving as a fellow of the American Academy of Arts and Sciences, president of the Association of American Pathologists, a member of the Association of American Physicians, of the American Society of Naturalists, and president of the Boston Society of Medical Sciences. Between 1900 and 1906 he was also a forthright advocate of the use of animals in scientific experimentation and testified before the state legislature against the anti-vivisection movement.

In 1883, Harold Clarence Ernst married Ellen Lunt Frothingham from a prominent Boston family; her brother was a U.S. Congressman. They had no children. Dr. Harold C. Ernst died on September 7, 1922 at the Jordan Hospital in Plymouth, Massachusetts. He was 66 years old.


Further Reading

1. Warner, John Harley. "Ernst, Harold Clarence (1856-1922), bacteriologist and physician." American National Biography. 1 Feb. 2000; Accessed 28 Oct. 2020. https://www-anb-org.ezp-prod1.hul.harvard.edu/view/10.1093/anb/9780198606697.001.0001/anb-9780198606697-e-1200259.

2. Wolbach, S. B. "Harold Clarence Ernst (1856-1922)." Proceedings of the American Academy of Arts and Sciences 60, no. 14 (1925): 621-24. Accessed October 28, 2020. http://www.jstor.org/stable/25130085.