34 
height. The application was made between 2 and 3 p. m. ona bright, 
dry day. At the same time a block of trees was sprayed with kero- 
sene, or refined petroleum. The weather continued fair and dry for 
four days, and there was no rainfall of any amount prior to April 11. 
After the second day the kerosene had very largely evaporated, the 
treated trees showing only a very light discoloration. Trees treated 
with crude oil, on the other hand, were still very wet and oily looking. 
The full-grown female scales of Diaspis pentagona were thoroughly 
soaked and were permanently preserved, apparently, in the oil and had 
scarcely changed color and were not drying up. After six days a 
slight change in the coloration of the female scale insects began to be 
observed, the color shghtly altering from light lemon to light orange. 
This change in coloration is a certain indication of the death and grad- 
ual drying up of scale insects, which usually change from lemon to 
orange and finally to brown or black in the different stages of drying 
after being killed by an insecticide. Three weeks after the application 
the trees treated with the crude oil were distinctly greasy in appear- 
ance and blackened by the oil. Trees sprayed with the pure kerosene 
gave no indication of having been treated at this time, the oil haying 
entirely evaporated. Curiously enough, the grass growing about the 
trees treated with these oils seemed to be more affected by the refined 
than the crude oil, being somewhat yellowed. This grass had been 
sprayed pretty heavily with the oil to see what result would follow. 
Two weeks later—namely, five weeks after the application—the bark 
of the trees treated with the crude oil was still dark and distinctly oily. 
All the trees treated with oil were leafing out and blooming just as 
freely and fully as untreated trees. The grass, which had shown yel- 
lowing at the outset, bad entirely recovered and was apparently unin- 
jured, seeming to indicate, at any rate, that grass will stand a consid- 
erable application with both crude petroleum and the refined oil without 
being killed. This fact is interesting in connection with the use of 
this substance against white grubs on lawns. (See Pl. L.) 
Lime, sulphur, and salt wash.—A mixture of this substance was 
prepared, differing slightly from the formula given in Farmers’ Bulle- 
tin No. 19 in that the amount of lime was somewhat reduced, namely, 
from 40 to 30 pounds. This reduction in the amount of lime was made 
simply because in the ordinary formula the lime is very greatly in 
excess and remains as a pure lime sediment in the wash and has to be 
kept in suspension by agitation. Even as thus reduced there is still a 
considerable excess of lime. The formula followed was: 
Time «22s nce ee seh oe see ee oak ee ee pounds... 30 
Sulphur 2.2 20. 222... Sok PAR ee ee doss see 
Salt 222.2. S305. SSE Ae Se ee ee do ssl 
Water: 2.6 ci Ue Pcie Se os eee eee gallons. 60 
The mixture was steam boiled altogether in barrels about four hours 
and applied March 23 and repeated March 24. The hot liquid was 
