28 



trees in February with 25 per cent kerosene and not a tree was living 

 on the 28th of April last. He was at present making midsummer 

 experiments. It seemed to him that atmospheri(3 conditions were at the 

 bottom of the difficult}^ and he thought it would be necessary to go 

 back to the old whale-oil-soap remedy which destroyed the scale more 

 effectively and was less liable to injure the trees. It would not be 

 wise to substitute crude petroleum for whale-oil soap. After three 

 years experience with kerosene, whale-oil soap, and gas he was of the 

 opinion that there are other conditions which must be studied more 

 seriously in the future than in the past, and he heartily agreed in the 

 opinion of the chairman that cooperation is desirable. He believed it 

 would produce better results in the future. We must not confine our 

 labors to the territorial boundaries of a State but go outside for infor- 

 mation, suggestions, and the experience of others. 



Mr. Fletcher stated that he was glad to hear what had been said 

 about whale-oil soap and crude petroleum. He had never yet been 

 able to see what object there was in trying to use petroleum. The. 

 results were too conflicting and always unsatisfactory, and the question 

 of cost in the destruction of the apparatus was never considered. 

 There was very slight injmy to the hose in the use of potash whale-oil 

 soaps, which could now be obtained of pretty uniform manufacture, 

 and had been giving good results. These are always to be had and 

 easy to get to most places. You can be sure of getting your whale-oil 

 soap within a week or ten days, while he had found there was consid- 

 erable difliculty in getting crude petroleum. He was of the opinion 

 that there is room for experiment with much weaker mixtures of the 

 potash soaps during the summer. His experience had been in favor 

 of the potash soaps in preference to the crude petroleum or kerosene 

 mixed wdth water. Even with the old kerosene emulsion there is some- 

 times unexpected injury to trees, which was always put down to differ- 

 ence in the oil or in the water. He was satisfied for the present that 

 the whale-oil soap was the safest remedy ; at any rate, it is the safest 

 for those who are official entomologists, and have to recommend formulae 

 to people who will make a mistake if the}' possibly can. 



Mr. Sanderson stated that he had not had much experience with 

 crude petroleum, but so far his experience has been favorable. He 

 sprayed an orchard of one hundred trees on the Delaware River with 

 crude petroleum in the latter part of January, on a cloudy da}^, with a 

 little hail and rain soon afterwards. The trees were mainl}'' Bartlett, 

 Kieffer, and Manning pears, which had been sprayed the year before 

 with pure kerosene and somewhat injured, but which had recovered. 

 Two months later, in March, he sprayed another lot of one hundred trees 

 with 25 per cent solution of crude petroleum. It was a very windy 

 day, and almost all the trees previously sprayed got a dose of the 25 per 

 cent solution on one side. Examination shows no injury on either lot. 



