German gynecologist; born at Gnesen, province of Posen, Prussia, Aug. 1, 1841; died at Charlottenburg, near Berlin, July 25, 1894. He received his education at the gymnasium of his native town and at the universities of Berlin, Prague, and Heidelberg, being graduated as doctor of medicine in 1864. In 1866 he engaged in practise as a physician in Berlin, where he was admitted to the university as privat-docent in 1868. Three years later he gave up general practise, and became aspecialist in gynecology. Resigning his position in the university, he in 1877 removed to Heidelberg, where he established himself as a gynecologist.
Cohnstein has written several essays and books, especially on gynecology. Among these the following may be mentioned: "Ueber den Muskeltonus" (awarded a prize by the Brussels Academy); "Ueber Alte Erstgebärende"; "Ueber ein Neues Perforationsverfahren"; "Ueber Vaginitis Exfoliativa"; "Lehrbuch der Geburtshilfe"; "Grundriss der Gynäkologie."
- Pagel, Biographisches Lexikon, s.v., Vienna, 1901.