76 
20 per cent, of kerosene, cost $3.62 for a hundred gallons of the 
diluted mixture. "Tak-a-nap" soap, a pound to the gallon, costs $5 
a hundred gallons, and the ordinary solution of whale-oil soap, $8 
for the same amount. "Frutolin" costs $25.10 per hundred gallons 
when diluted with 9 parts of water to i of "Frutolin," as advised 
by the manufacturers. 
General Summary. 
I. The cheapest and most efficient of the eleven insecticide mix- 
tures thoroughly tested against the San Jose scale were the simple 
lime and sulphur mixtures (without salt or blue vitriol) dissolved b^/ 
boiling together. They cost, for materials, from 84 cents to $1.03 per 
hundred gallons of the fluid spray, varying according to the propor- 
tions of the chemicals used. Infested trees treated with these solu- 
tions in March, bore about one fifth as many scales the following 
September as companion trees not treated. 
2. The next in value was the ''California wash" made with 
lime, sulphur, and salt, at an expense of 94 cents to $1.07 per hun- 
dred gallons, and the "Oregon wash" of lime, sulphur, and blue 
vitriol, costing virtually the same. 
3. There was a marked and very important difference in the 
final effect of these washes and mixtures, dependent upon the time 
of their application, the midwinter treatment yielding a result far 
inferior to that of early spring. 
4. The cold solution of lime and sulphur made with soda was 
found less than one third as effective as the washes dissolved by 
boiling. Its materials were also somewhat more costly, varying, 
according to the proportions of the ingredients, from $1.24 to $1.44 
per hundred gallons. 
5. The petroleum preparation known as "Scalecide," which has 
the advantage that it may be prepared for use by simply diluting 
with water, was found somewhat less efficient than the lime and sul- 
phur mixtures, and cost about 2]/^ times as much as the raw mate- 
rials of those preparations. 
6. Whale-oil soap compared very well with the "California 
wash," but at a cost approximately eight times as great. 
7. Less confident statements may be made with reference to Ore- 
gon washes made with hydrated lime, and to the commercial insecti- 
cides known as "Con Sol" and "Calcothion," experiments with these 
substances having been made on too small a scale to warrant final 
conclusions. They strongly indicate, however, that, with the excep- 
tion of "Con Sol," these mixtures have an insecticide value some- 
