194 Investigations in Plant Pathology 



properties of the most important species, particularly of the patho- 

 genic forms." ^^ By 1890 ^^ among twenty-eight medical students, 

 eleven were studying bacteriology under Welch and Abbott, and 

 Dr. William Osier, later a friend of Smith, had charge of the 

 medical department of the hospital. 



Smith obtained from Dr. Gray in 1890 a formula for the 

 preparation of nutrient agar. His entry in his " Record Book of 

 Culture Media" read as follows: 



Add to one litre of distilled water 1-2% of Agar and boil tivo days (not 

 necessary to boil at night). Add 1% of peptone; \% of Liebig's Fleisch 

 extract and whites of two eggs. |% of grape sugar may also be added, if 

 desired. Neutralize with carbonate of soda solution and filter. By boiling 

 two days the agar will readily pass through one thickness of filter paper, 

 and does not even require to be put on the hot water filter. 



As a second paragraph. Smith added: "Dr. Gray showed me 

 many tubes prepared in this way and they were very clear and 

 satisfactory. He much prefers Liebig's extract to meat infusion 

 and says it gives just as good results." The work of preparing 

 nutrient media to cultivate and examine the growth microorgan- 

 isms make when infecting plants must have been thought of by 

 Smith as part of his regular duties. A list of subjects for special 

 study, prepared February 27, 1890, must have been planned for 

 hours outside of his laboratory. These were (1) photography 

 including microphotography, (2) drawing, (3) a review of 

 German grammar, (4) a review of botanical Latin (5), study of 

 the Italian language, and (6) razor honing. 



During February, March, and April of that year, Waite, as a 

 part of held work in pear blight, went to Georgia to test a series 

 of fungicidal treatments in connection with this disease caused by 

 bacteria." This was the year when Galloway and Fairchild at 

 Vienna, Virginia, were to demonstrate that 93 to 99 per cent of 

 the grape crop could be saved from black rot by the use of copper 

 fungicides at a cost of 1 to 2 cents per pound of fruit." The 



'^^ Idem 51: 123 f., July 1886;; also, idem 55: 64. Concerning Bolton's associa- 

 tion with Welch in bacteriological instruction, idem 60, Nov. 1887; 6A: 54, Mar. 

 1888. 



""^ Johns Hopkins Bulletin 1 (8): 99, Nov. 1890. 



*" Report of the Chief of the Division of Vegetable Pathology for 1890: 394. 



" Erwin F. Smith, Fifty years of pathology, op. cit., 21. See also Galloway's 

 discussion, Treatment of black rot of the grape, Division's report of 1890, op. cit., 

 394-396. Also Jour. Mycology 6(3): 89-95, Jan. 6, 1891. 



