26 
ing to notes made up to June 12. Until that date the sprayed trees 
remained oily and the odor of the crude petroleum could yet be 
detected. It is a reasonable conclusion, then, that the scale can not 
live so long under such a coating of oil. He had concluded that the 
25 per cent crude petroleum in mechanical mixture was better than 
refined kerosene of the same strength. 
Mr. Woodworth said that when the bulletin from the New Jersey 
Station came out it was heralded all over California, and he had to 
write more letters in regard to the kerosene and crude-petroleum treat- 
ment than about any other insecticide. Crude petroleum in California 
is a very indefinite term, since there is a crude petroleum from Ven- 
tura which is as thick and black as molasses, and from that it varies 
to crude petroleum which is almost as thin as gasoline. Even in a 
single well the product varies according to depth and age, and distilla- 
tions show that it varies greatly in composition. He had been assured 
that the Eastern product varied also, and was of opinion that before we 
can recommend any percentages of crude petroleum we will have to 
establish a criterion of excellence. The different kinds of crude 
petroleum he had experimented with in California produced very dif- 
ferent results—strikingly different. There is also a very decided dif- 
ference in results according to time of spraying with the same oil. 
Thus spraying before rain and after rain may produce entirely different 
results. He had sprayed with some forins of crude petroleum without 
injury which would have thoroughly destroyed the foliage at another 
time of day. The amount of water in the leaf may determine to a 
certain extent the damage by the oil. It seemed to him, therefore, that 
another thing that must be done before we can really properly under- 
stand the action of the oil will be to study the effect of the oil upon 
the vegetable tissue. Perhaps this had already been done, but it was 
still in large part a mystery to him. 
Mr. Webster said he had used oil from two wells located in differ- 
ent. parts of Ohio this year, and although the analysis ran almost 
exactly the same in each case the effect has been different. In the one 
case he had not seen the orchard for several weeks, but when he last 
saw it the peach trees seemed to have been in many instances killed 
by the use of crude petroleum. He could not say whether the oil had 
been applied just before or just after a rain. In the other case the 
trees sprayed were seedling apples on the experiment farm, the experi- 
ment being made to determine if possible the effect upon the trees and 
not against insects. Some of the trees leaved out at the proper time 
about as freely as usual, while others had no leaves at all. At the 
present time, however, there was no apparent difference whatever in 
them, all having finally leaved out precisely the same. It was evi- 
dently nothing but a temporary injury. His experiments had pro- 
duced such varied results that he was badly mixed up and did not favor 
