Ernst, Harold Clarence


Dates:          b. 1856; d. 1922

Locations:    Demonstrator in Bact. (1885‑1891); Assistant Professor (1891‑1895); Professor of Bacteriology, Harvard Medical School (1895‑1920?); Bact. Lab., Boston City Health Dept. (1894‑)

Training:      AM; MD Harvard 1880; 1879 and 1890 in Koch's laboratory

Fields:          medical; milk

Publications: "How Far May a Cow be Tuberculous before Her Milk Becomes Dangerous as an Article of Food," Bull. Hatch Agr. Exp. Sta. no. 6 (1890); Infectiousness of Milk (1895); editor of J. of the Bost. Soc. of Med. Sci. which became Journal of Medical Research

SAB Involvement:  Charter SAB member; SAB council member 1900; resigned SAB 1917 but reappeared at the 1919 meeting; Secretary and Pres. Assoc. Am. Pathologists and Bacteriologists (1901, 1909)

Archive Files: 2‑IXC, Fold 77, Hist of Dept. by Hon H. Hanks, 1952;  See also, his Obit in The Boston Medical and Surgical Journal 187 (1922): 424‑425; J.W. Farlow, "Harold Clarence Ernst," Bost. Mass. Hist. Soc. 1922; D.H. Bergey, "Early Instructors in Bacteriology in the United States," J. of Bact. 2 (1917): 595‑601; Nat. Cyc. American Biog. 20, 1929 (has birth date as 1855;) ANB; DAB



     In 1885, he was appointed as demonstrator in bacteriology, and conducted "unofficial" classes and studies, consisting of six lectures as an introductory class to general pathology.  The Chair of Bacteriology was established in 1891, and Ernst became Assistant Professor.  In 1895, he rose to full professor.  He engaged in private practice until 1895, and served in the out patient department of MGH until 1900.  

     Appointed an agent of the Boston Board of Health in Oct. of 1894.  Published in 1895 an extended report on The Infectiousness of Milk, in which he argued that the tubercle bacillus is found in milk from reactors even when no lesions are apparent in the udder.  Most improvements in Pasteurization did not come about until 1900 1905.  Performed diphtheria diagnosis and produced antitoxin at Harvard in 1895, modeled after Pasteur Institute’s, until 1898.  

     At the 1899 SAB meeting Ernst presented a paper on "Demonstration of Actinomycosis and the Causative Fungus."   

     Ernst worked on immunization against rabies, the etiology of suppuration, the colon and typhoid bacilli, the morphology of the tubercle bacilli, cultivation of the gonococcus, cultivation of anaerobes, the viability of tubercle bacilli in natural environment, differences between human and bovine tubercle bacilli, and the techniques of sore throat diagnosis.  He developed an apparatus for sterilization of surgical dressings prior to Lister's book; demonstrated that tubercle bacilli may be transmitted through the milk of healthy cows; he produced all tuberculin used in Boston; pushed for the sterilization of milk; performed or supervised most diphtheria work, etc.

     With Smith and George Kinnell, Ernst issued a special commission report on the effectiveness of the tuberculin test.  The report, however, did not persuade the legislature.

     He also founded the Association of American Pathologists and Bacteriologists and the Boston Journal of Medical Sciences which in 1904 became the Journal of Medical Research.  The journal ceased publication with his death in 1922.