Fungous Disuasi^s oi- Plants, Puacii Ylllows 133 



mixture had given the best results, better than luiu celeste and 

 other compounds. Bordeaux mixture was found a dependable 

 remedy for potato diseases. 



Throughout the lirst half of the year 1887 Scribner's assistant, 

 Erwin Smith, contemplated enrolling at either Harvard University 

 for further study of fungi or at the Johns Hopkins University in 

 Baltimore for special biological study under Martin or Welch. In 

 fact, on April 5, 1887, he had gone to Dr. John S. Billings of the 

 Surgeon General's Office at Washington and obtained a letter of 

 introduction to President Daniel Coit Oilman of the Hopkins 

 University. In Jiine, however, Smith was ordered by Scribner to 

 complete his report on the potato rot, and prepare to take up a 

 commission as of July 1 to investigate a serious disease threatening 

 the American peach-growing industry — the yellows. Peach yellows 

 was a disease which had bafHed the scientific ingenuity of even 

 Thomas Jonathan Burrill and Joseph Charles Arthur. 



Burrill's and Arthur's studies of peach yellows had been incom- 

 plete. Burrill in 1881, when he announced with "much con- 

 fidence" his belief that peach yellows, like pear and apple twig 

 blight, v/as of bacterial origin, cautioned his readers that he had 

 not given the "full investigation" to the peach malady as to the 

 pear disease."^ Arthur, whose budding and grafting experiments 

 w^ere made to reproduce the yellows in healthy trees and by 

 several years preceded the work of Smith, failed through no fault 

 of a proper scientific procedure but because, as he explained to 

 Smith by a letter of December 4, 1890, " the bud or graft died 

 before becoming fairly started." Arthur by 1891 regarded his 

 work at the Indiana Agricultural Experiment Station as " so 

 diverted into the domain of vegetable physiology that pathological 

 subjects," he said,'* "have fared poorly for some time." He, 

 however, told Smith in his letter of December, 1890: " I am 

 delighted to hear that you are progressing so favorably with your 

 work on peach yellows. If you complete a full explanation of the 

 cause and conditions of the disease it will be a notable achievement 

 and a brilliant triumph for science." 



In July, 1887, Smith v/ent into the field to investigate peach 

 yellows. On August 3, C. W. Garfield wrote to him: 



""" American Naturalist 15: 527, 1881. 

 ''* Letter, Arthur to Smith, May 14, 1891. 



