206 LETTER-FILES OF S. W. JOHNSON 



the physiology of plants and animals"; and the first 

 use made by the Connecticut Station of income from 

 the Hatch fund was to establish a new department for 

 the investigation of fungous diseases of plants. Dr. 

 Eoland Thaxter (who resigned after three years' ser- 

 vice to accept a professorship in Harvard) was the 

 first mycologist in charge of this department. During 

 his term of office he identified and described the 

 organism causing potato-scab — Oospora Scabies — 

 which had long been uncertain and a subject of con- 

 troversy. His successors in the department have 

 maintained the high standard set at its inception. In 

 1889, at Professor Johnson's desire, Dr. Thomas B. 

 Osborne, a member of tlie station staff, undertook a 

 study of the nitrogenous matters contained in the 

 kernels of oats. This investigation also was supported 

 by the income of the Hatch fund. It proved to be the 

 beginning of a sustained research in protein chemistry 

 which has developed — in a laboratory of the Connec- 

 ticut Station — \\'ithout interruption up to the present 

 time. Lately, through aid from the Adams fund, and 

 in cooperation with the Carnegie Institution of Wash- 

 ington and with the Sheffield Scientific School of Yale 

 University, the scope of this work has been extended 

 to include many important problems of nutrition and 

 growth. 



While gathering together, in the autumn of 1871, 

 material for his essay on soil exhaustion and rotation 

 of crops. Professor Johnson was so impressed by the 

 unsatisfactory and meager data available as a basis 

 for the estimation of nutritive elements removed from 

 the soil by the growth of tobacco, that he omitted all 

 reference to this crop of so great importance to the 



