44 
San Jose scale as far back as 1897, publishing in the Bulletin of 
the Michigan Experiment Station the earliest report of an exact 
experiment with it which I have seen ; and Professor Craig, of the 
Horticultural Department of Cornell University, has also tried it 
on this scale. Professor E. D. Sanderson, formerly of the Texas Ag- 
ricultural College and Experiment Station, has used a form of it 
on the cotton boll-weevil. Professor Thomas B. Symons, of the 
Maryland Agricultural College and Experiment Station, used it 
experimentally on the San Jose scale, and on beetles infesting the 
aster. Professor J. L. Phillips, State Entomologist of Virginia, has 
also tested it on the San Jose scale with unusual thoroughness; Pro- 
fessor F. M. Webster, Entomologist of the Ohio Agricultural Ex- 
periment Station, had it tried four years ago by an assistant, Mr. 
C. W. Mally (now Government Entomologist in Cape Colony, 
South Africa), on a variety of insects, including the chinch-bug; 
and two of my own assistants, Mr. E. S. G. Titus and Mr. G. I. 
Reeves, have used it on scale insects, caterpillars, and moths ; have 
tested it for the destruction of fungus parasites of the green leaf ; 
and have determined its effects on various kinds of vegetation when 
applied in a way to kill the insect enemies of the plant. Most of 
these experiments are unpublished, but their results have been gen- 
erously placed at my disposal for use in this brief discussion. 
Although no one of those here mentioned has made a trial of the 
gasoline torch for all the insecticide and fungicide purposes which it 
might possibly serve, the total results have a considerable value as 
showing definitely some things which can and some things which 
can not be done with it, and as indicating the directions in which 
further trials may be had if indeed it appears that further trial 
is necessary or worth while. Some variation and conflict in the 
reports of some of these experiments are evidently due to differences 
in the apparatus used, this varying from a poorly constructed and 
feeble torch, made in Illinois especially for insecticide work, to a 
large and powerful blast-lamp, used in Texas for burning the thorns 
off prickly pears. 
The idea that exposed insects of small size may be quickly de- 
stroyed by the sudden and brief application of a blast of very hot air, 
or even of actual flame, without injury to the plant on which they 
may be feeding at the time, strikes one favorably at first thought; 
and there seems, in advance, to be no obvious reason why this 
method may not hav^e a considerable practical value. The living 
animal is often more sensitive to sudden heat exposures than the 
living plant, and the margin between exposures fatal to each may 
in some cases be so wide as to make this method fairly safe in 
