New YorK AGRICULTURAL EXPERIMENT STATION. 421 
solution of the same brand. While the value of the sediment 
was not definitely known, it has been supposed that the effi- 
ciency Of lime-sulphur washes as insecticides is chiefly deter- 
mined by the soluble lime-sulphur compounds, and that in com- 
parison with these the insoluble sludge is a much less import- 
ant constituent. To determine the relative effectiveness of the 
soluble and insoluble ingredients of the lime-sulphur wash on 
the San José scale was the aim of the following experiments. 
EFFECTIVENESS OF SEDIMENT ON THE SAN JOSE SCALE, 
The trees in these experiments were much infested with the 
San José scale. The sediment was taken from several barrels 
of a commercial brand, containing about fifteen per ct. of in- 
soluble material, which was obtained by filtering. The filtrate 
was then repeatedly washed until tests showed no traces of 
soluble sulphur. This filtrate, when dried and ground, pre- 
sented the appearance of a greyish powder. Chemical analyses 
showed that the sediment consisted largely of calcium sulphite, 
calcium sulphate, and free sulphur. 
Series I.—In this first series several tests were made with 
the sediment, in the proportions of one gallon of the stiff paste, 
thinned with nine or eleven gallons of water. The mixtures 
were applied with a spray pump. The applications after drying 
left a light coating on the trees, which was of a bluish gray 
color. For purposes of comparison some treatments were 
also made with lime-sulphur solution testing 33° Beaumé at 
dilutions of one gallon to either nine or eleven gallons of water. 
Results on scale-—Applications of the sediment of either 
dilution had no appreciable destructive effects on the scale. 
The production of the young at the beginning of the breeding 
season was apparently as abundant as that occurring on the 
untreated trees, and throughout the summer there was no ap- 
preciable difference in the amount of infestation of the checks 
and of the trees sprayed with the sediment. The treatment 
with the clear solution, diluted with nine parts of water, prac- 
tically destroyed the scales, as only an occasional active larva 
was observed. The weaker preparation, containing one gallon 
