59 



Mr. Marlatt added that Dr. Forbes's experiments had had special 

 relation to the subsequent action of washing rains, and that they 

 seemed to show that such rains had no effect on the benefit coming 

 from the wash. Furthermore, Dr. Forbes had actually thoroughly 

 washed with water trees which had been treated, and again the action 

 of the insecticide had not been decreased. It was on this account that 

 Professor Forbes's experiments were of so great importance and 

 opened the whole subject for renewed investigation, indicating, as 

 they seemed to do, that the wash could be used in regions where rains 

 are frequent as well as in dry climates like those of the Pacific coast. 



Mr. Smith suggested that perhaps a large number of small trees had 

 been used in the experiment. 



Mr. Felt in this connection called the attention of the association to 

 the influence of rains on the wash in New York State and considered 

 it to be apparently what would be expected. He had examined some 

 treated limbs and found the live female scales quite abundant. He 

 was informed that the application had been followed b}^ quite a little 

 rain, and in his own experiments he was in hopes that some would 

 fall, and the rain came immediatel}' after, thus furnishing him exactly 

 what he desired. The entire experimental orchard was sprayed, and 

 it seemed very doubtful if the work could be completed before the 

 rain came, but the work was finalh" finished. The rain continued for 

 about three days, so that he considered it a ver}^ severe test. The 

 treated trees were looked over at different intervals until about ten 

 da3\s ago, and of the trees treated with the wash some at least con- 

 tained living female scales, although most of them were not very badly 

 infested. The most of the living insects were, as Dr. Smith had 

 stated, under masses of scales. The wash did not penetrate into the 

 masses, and it was his experience that where the bark was rough the 

 insects were not seriously affected. He thought that when the wash 

 was applied the trees should be dry. 



Mr. Smith, in reply to a question, said that one of the farmers whom 

 he had advised to use the kerosene emulsion had used 5 pounds of soap 

 instead of one-half pound, as ordinarily recommended. The resulting 

 mixture was ver}^ satisfactory, but it was a fatal one. The emulsion 

 was diluted 10 times and applied to the trees just as the leaves were 

 dropping, and the results were very disastrous. 



Mr. Scott stated that in his paper he had not included his experi- 

 ments with summer washes. He explained in regard to crude oil in 

 soap emulsions that as low as 10 per cent of oil very badly damaged 

 trees in foliage, whereas the 10 per cent in mechanical mixture did 

 ver}^ little damage; he had found wherever the soap was used in crude 

 oil or kerosene the results were more disastrous than in case of the 

 mechanical mixture. Experiments had been made last winter where 

 soap had been used in connection with the oils to determine whether 



