Koch's Discovery of the Method of Plate-culture of Micro-organisms

Abstract

READING the interesting notice of Robert Koch which appeared in NATURE of June 2, I was reminded of an incident mentioned concerning his early scientific career in the preface to Cohnheim's “Gesammelte Abhandlungen.” Cohnheim, the pioneer of what has been sometimes termed physiological pathology, died in 1884 at the early age of forty-five. The preface to his collected works, published in the following year, contains a charmingly written memoir of him from the pen of his friend W. Kuhne, the accomplished Heidelberg physiologist. The obituary notice of Koch in NATURE rightly stressed the immense value to bacteriology of his invention of the plate-method for obtaining pure cultures of micro-organisms. The incident reported by Kuhne in his memoir of Cohnheim has reference to that, and to Cohnheim's contact with Koch in consequence of it in the year 1875. At that time Cohnheim was already full professor of pathology in the University of Breslau, and his brilliance as an investigator was already attracting to his laboratory men of promise from all parts. Koch, on the other hand, was in country practice in Silesia, and quite unknown to the scientific world. Koch's discovery of the plate-method led to Cohnheim's discovery of Koch, and the enthusiasm and remarkable prevision at once shown by the young professor of pathology regarding his unknown compeer, only two years younger than himself, are strikingly told by Kuhne. His words run:—