Harold J. Conn

Harold J. Conn
Harold J. Conn in 1948
Born	May 29, 1886 Middletown, Connecticut
Died	November 10, 1975
Nationality	American
Education	Wesleyan University (Ph.D.) Cornell University (Ph.D.)
Occupation	Agricultural bacteriologist
Employer	New York State Agricultural Experiment Station
Known for	Soil microbiology and bacterial staining techniques.
Notable work	Manual of Methods for Pure Culture Study of Bacteria (1920) Biological Stains (1925) History of Staining (1933; 1948) Staining Procedures (1944–55; 1960) Manual of Microbiological Methods (1957)

Harold Joel Conn (May 29, 1886 – November 10, 1975)

Early life and education

Conn was born in

He attended Wesleyan University, where his father had started an early course in bacteriology,^[1][2][6] gaining a doctorate in 1908, despite being obliged by his deafness to copy another student's lecture notes.^[2] He went on to pursue a second PhD in the relatively new discipline of soil bacteriology at the New York State School of Agriculture, Cornell University, under the direction of T. L. Lyon, who specialized in agricultural science rather than bacteriology. He completed this PhD in 1911;^[1][6] his thesis is entitled "A study of seasonal variation among the bacteria in two soil plats of unequal fertility".^[7] Conn showed that soil bacteria can sometimes increase when the soil is frozen; the counterintuitive result led to considerable discussion in the scientific community.^[1]

Career, research and societies

In 1911, Conn joined the New York State Agricultural Experiment Station in Geneva, New York as an associate bacteriologist. He spent his entire career at the station, which became part of Cornell University, being appointed chief in research in 1920 and, in addition, professor of bacteriology in 1945. He initially worked under H. A. Harding, a dairy bacteriologist, and from 1913 under Robert S. Breed. Conn retired from the station in 1948.^[1][6]

Conn's research at the station continued his PhD investigations on soil bacteria. He invented a technique to stain bacteria so that they could be studied under the

In 1920, Conn published Manual of Methods for Pure Culture Study of Bacteria, an influential work that was important in devising methods to classify bacteria. In 1923, he published a successful general textbook, Bacteriology; the text had been initiated by his father, who had died in 1917. He edited the Manual of Microbiological Methods (1957)[1] and was a trustee of Bergey's Manual of Determinative Bacteriology (1948–65).^[11]

He also published several texts on staining including Biological Stains (1925), History of Staining (1933; 1948)

Conn published more than 200 journal articles, predominantly in the fields of soil microbiology and bacterial staining techniques.[6] He wrote two biographies of his father, Herbert William Conn: one appears in Bacteriological Reviews and deals with the foundation of the Society of American Bacteriologists; the other unpublished text, "A Religious Scientist at the Turn of the Century", includes a bibliography.^[4][5][13] Other unpublished works include an autobiography and a history of the Biological Stain Commission (1955).^[2][13] His papers are archived at the Division of Rare and Manuscript Collections of Cornell University Library.^[13]

Personal life

Conn's hearing loss was progressive throughout his life. Deafness significantly impaired his ability to communicate face to face with other scientists. He was little helped by hearing aids, and also had difficulties with lip reading.^[1][2]

He was married; he and his wife had a son and a daughter, Jean, who also became a bacteriologist and was Conn's long-term assistant.^[1] She married the mycologist Vincent W. Cochrane, with whom she collaborated.^[14][15] Conn's wife died in 1963. Conn died in Geneva, New York, in 1975, aged 89.^[1][5][6]

References