260 REPORT OF THE DEPARTMENT OF ENTOMOLOGY OF THE 
OBJECT OF TESTS. 
The object of making these coordinate tests was to determine, 
if possible, some of the causes for the many uncertain and con- 
flicting results in the use of kerosene and crude petroleum; and, 
at the same time, to compare the use of these oils with fumiga- 
tion, especially as regards practicability and cost. 
CONDITIONS. 
All tests in the Second Judicial Department (on Long Island 
and in Westchester Co.) were made in the orchard. The trees 
were first sprayed, then pruned. The pruning was done after 
the spraying rather than before, as is the common practice, be- 
cause nothing could be saved by pruning first; since just as much 
oil must be thrown, when using a Vermorel nozzle, to cover one 
small branch as to cover many. Furthermore, where crude petro- 
leum was used, by first spraying and then pruning, untreated 
branches could be removed. 
All applications were made by means of a Gould tripod “ Kero- 
water” pump, and Gould Vermorel nozzles having the smallest 
aperture made. All oils were purchased of the Standard Oil Co. 
In all cases where attempts were made to apply mechanical 
mixtures of oil and water of a certain percentage the mixture 
varied at least 5 per ct. each way. Thus, where we attempted to 
use 1% per ct., the amount fluctuated between 10 and 20 per ct.; 
between 20 and 30 per ct. for 25 per ct.; between 45 and 55 per 
et. for 50 per ct.; and between 55 and 65 per ct. for 60 per ct. 
During the spraying at any given percentage and whenever the 
pump was changed from one percentage to spray a different one, 
it was tested to determine if it gave approximately the required 
proportion of oil. 
TESTS OF OILS AS WASHES FOR SAN JOSE SCALE 
INSECT. 
During the winter of 1899 and 1900, preliminary tests of two 
grades each of kerosene and crude petroleum were made. The 
tests were divided into two series. Of the kerosene tests, Series 
I consisted of 100° flash test (‘‘ distillate”), costing 1214 cents 
