Introduction of London Purple. 67 



was in answer to theirs of March 19, 1878, so it was written 

 sometime early in April." 



In another letter, Dr. Bessey has informed me that during a 

 visit which one of the Hemingway firm paid him in Iowa, the 

 statement was made that the three kegs sent to Iowa were the 

 first sent to America ; and the first small packet sent in a letter 

 was one of three which were mailed at the same time, the other 

 two packets being addressed to two gentlemen in the United 

 States. One of these was Professor A. J. Cook, then of Lans- 

 ing, Mich. The name of the other was forgotten, for no reply 

 had been received from him. Professor Cook's answer had 

 been delayed or had proved unsatisfactory, for all the kegs of 

 the first shipment went to Iowa, as above stated. 



The United States Department of Agriculture has also been 

 active in bringing London purple to the attention of horticul- 

 turists. In the annual report of the Department for 1878, page 

 144, is given a chemical analysis of the poison, and its use 

 is suggested as a substitute for Paris green. The first direct 

 recommendation that is found in the government reports to 

 this effect was made by Riley on page 248 of the same publi- 

 cation. He advised the destruction of the juniper web-worm 

 by treating the parts infested with either Paris green or London 

 purple. The same was also made to apply to the apple coleo- 

 phora. Experiments to test the value of London purple were 

 carried on this year by Riley, and the work was so successful 

 that large quantities of the poison were distributed to various 

 cotton growers in Georgia, Alabama, and Texas, where it was 

 to be used in the destruction of the cotton worm, in 1879. The 

 result of these tests was so satisfactory that London purple 

 was even more strongly recommended than Paris green. When 

 applied in a dry state, the proportions which appeared most 

 promising to Dr. Riley were one-half pound of the poison to 

 eighteen of the diluent. When used with water, one-half pound 

 of the powder could be used to advantage in about fifty gal- 

 lons of water. During the spring of the same year, 1879, A. R. 

 Whitney, of Franklin Grove 111., "found it to be a perfect an- 

 tidote to the canker-worms. 1 ..." 



During this year, Trelease conducted some experiments for 

 J. H. Comstock, who at the time was chief of the Division of 



1 Kiley, U. S. Ent. Com. 1880, Bull. 3, 60, 61. 



