New YorK AGRICULTURAL EXPERIMENT STATION. 288 
York at Geneva and near Youngstown in Niagara County. The 
experiments were distributed well over the State with the hope 
that the treated trees would be subjected to a variety of weather 
conditions which, taken together, would give the wash a severe 
test and also furnish data showing, as far as possible in one 
series of experinrents, the effects of the treatment under different 
weather conditions. The extent to which this plan proved suc- 
cessful is shown on subsequent pages. . 
In making the selections much pains was taken to secure trees 
that were well infested with the scale but not seriously injured 
by other insects or diseases. But as extensive infestation and 
lack of care are very apt to go together it was, as a rule, difficult 
to find badly infested trees that were not weakened by lack of 
proper cultivation as well as by the scale. In order that the 
eonditions under which each experiment was made may be under- 
stood, a brief history of each orchard is given together with a 
description of the condition of the trees at the time of treatment. 
METHOD OF DETERMINING RESULTS. 
As a basis for the determination of results, check trees were 
selected from the orchards in which the experiments were made, 
much pains being taken to include only those which, in point of 
infestation and vigor, would average about the same as the treated 
trees. No attempt was made to count the scales on the trees, 
either before or after treatment, as it was considered practically 
impossible to count enough of them to furnish adequate data upon 
which to base results. This method was found very satisfactory, 
however, for laboratory experiments with infested apples. In all 
of these experiments the results were based upon careful com- 
parisons, made as frequently as circumstances would permit, be- 
tween the treated and check trees, especial pains being taken to 
ascertain the condition of the trees toward the close of the season 
both as to the character of the foliage and fruit and the degree 
of infestation. 
No attempt was made to conduct the experiments upon a com- 
mercial scale for it is considered that in this case, as with any 
insecticide, the point first to be determined is the degree of its 
