27 



recommending the use of kerosene of any sort. He was of the opinion 

 that the ^■a^iation would be just as great in the crude article as in the 

 refined. 



Mr. Hopkins said that in West Virginia they have a great variety 

 of petroleum, from that as thick and black as molasses to the thin 

 light-colored product. The oil obtained from the Standard Oil Com- 

 pany is a mixture of all kinds except the heavy oil. The heav}^ oil is 

 used for lubricating machinery. He had obtained some results which 

 are quite at variance with the testimony of others and shows what 

 conflicting results can be obtained in different States. In one case he 

 recommended crude petroleum as an experiment in a large orchard 

 which was almost dead from the scale and which the owner refused to cut 

 down. It had been sprayed once with pure kerosene, which did some 

 damage and killed many scales, but the owner had allowed it to go with- 

 out treatment and the scales had again covered the trees. He sprayed 

 it with crude petroleum obtained in Baltimore. When he last saw the 

 orchard, in April, the trees were black and greasy, but underneath 

 the bark they were as healthy as ever, the leaves were coming out in full, 

 and the owner claimed that the crude petroleum had benefited them. 

 He was not recommending the oil, but simply giving this as an exam- 

 ple. His spraying was done in February and wherever the oil touched 

 the bark it remained dark and greasy for months afterwards. A thor- 

 ough examination failed to reveal any of the living scales, and he 

 believed that the young scales could not settle and live on the oily 

 surface. He felt very much encouraged. It is one of those problems 

 which require cooperative work. As a result of further investiga- 

 tion, he thinks it may become one of the best insecticides ever discov- 

 ered. He could not think of any better work than trying to find the 

 reasons for the great difierence in results in experimental work with 

 insecticides. 



Mr. Webster said he was unable to see what could l)e gained even 

 if crude petroleum should be perfected. It was true that we Avill have 

 to get something cheaper and more effective than whale-oil soap, which 

 if used on peach trees except during the winter will destroy the fruit, 

 but in view of the difficulty he had had in getting crude petroleum 

 and the high price asked for it, how much better an insecticide than 

 whale-oil soap would we have even if it was perfected i He thought 

 that entomologists who cared for their reputation would experiment 

 much and say little for publication, for the present at least. He fur- 

 ther stated that while experimentation was always in order, it would 

 be best to stick to the whale-oil soap until more obscurities in regard 

 to the use of petroleum had been eliminated. 



Mr. Johnson said he agreed with Mr. Webster. We have got to get 

 something better than kerosene for both peach and plum. In one 

 instance he had sprayed an orchard of two hundred 9-year old peach 



