52 
varying periods of time. The mildew does not seem to have been 
affected where the leaves were not injured, and was rarely affected 
where the leaves were burned sufficiently to cause them to curl 
and later to wither. Leaves that were treated to the flame for three 
seconds dropped off. Other leaves treated one second remained on 
the bush and were not perceptibly injured. Between these two times 
(which really represent flashing the burner over the surface and 
holding it there for an instant) the leaves show varying injuries. At 
first the mildew appeared to have been burned off, but specimens 
which had been thoroughly treated and left in the insectary were 
again covered with the mildew in five days. 
"Elm, Osage orange, box-elder, apple, cherry, plum, grasses, 
nasturtiums, cabbage, pine, cedar, Amorpha, walnut, rose-bushes, 
peach, and several other trees and ornamental shrubs have been 
treated at various times. I find that when the flame is held close 
to the foliage for a few seconds this is visibly injured. If held a 
short distance away the injury is not so great, but usually shows 
after a few days by the blackening of the leaf or by the browning 
and curling of the edges. Often leaves so treated will drop off. 
"To sum up : The use of sufficient heat to destroy effectually 
insect larvae of the kinds we treated, will injure the foliage and often 
the twigs." 
Mention may be made of a trial of the torch by Mr. Mally, in 
Ohio in 1898, the details of which can not now be given because 
the record is not accessible. This torch, obtained from Illinois, was 
put into Mr. Mally's hands by Professor F. M, Webster, with in- 
structions to give it a thorough test. It was taken by Mr. Mally 
on one of his field trips, used on a variety of insects, including the 
chinch-bug, and returned with the general report that it was un- 
satisfactory for its purpose. 
Use of the Gasoline Torch against the Chinch-bug. 
Notwithstanding the generally unfavorable character of the 
statements made to me concerning this torch by those best able to 
judge of its value, it seems that it may have a field of usefulness 
for the destruction of certain kinds of injurious insects. Thinking 
that it might profitably be tried in comparison with other aids to 
the trap and barrier method for the destruction of chinch-bugs as 
they come out of small grain in midsummer, I provided for a series 
of field trials with a first-class torch, in connection with other experi- 
ments on the chinch-bug made during the summer of 1904. To 
make sure of having a good example of this form of blast-lamp, one 
