50 
and there was a gentle breeze. Tree 116, a badly infested Lombard 
plum, showed serious injury July 3, at which time several limbs were 
dying and the remainder did not present a normal, vigorous appear- 
ance. August 9 the tree was dead and all the leaves thrown out in 
the spring had shriveled. Tree 117, a very badly infested Crawford 
peach, was also sprayed at the same time, and July 3 it was dead. 
It might be added that the oil was used liberally, and that in the 
case of tree 117 the infestation was so very bad that it was hardly 
expected that the tree would survive. 
Some comparative experiments with mechanical crude petroleum 
emulsions were made. The above-described oil from Titusville and 
an oil used in the experiments last year were tried. The latter was 
purchased in the Albany market as crude petroleum sold by the 
Standard Oil Company. It is a quite fluid greenish oil, and that used 
in 1901 gave a reading in the field of 41.8° Beaumé. Neither the 20 
nor 25 per cent emulsions of either oil injured the trees, so far as 
could be seen, this agreeing with the results obtained with the emul- 
sions of Standard oil in 1900. The Standard oil, that is the heavier 
one, appeared to be a little more effective as an insecticide, but asthe 
lighter Titusville oil has been used in 25 to 50 per cent emulsions 
without injuring the trees and with very satisfactory results as an 
insecticide, it would appear that the heavier the oil the less can be 
used with safety and the more effective it is as an insecticide. There 
is evidently a very narrow margin between the amount of this sub- 
stance necessary for satisfactory work against scale insects and that 
which will seriously injure or kill trees, especially peach and plum 
trees, and in the case of those very badly infested, particularly if the 
bark is quite rough, it is doubtful if enough oil can be applied to 
kill practically all the insects and at the same time not injure the tree 
seriously. 
The experiments tried last year with a combination of 1 pound of 
whale-oil soap to 4 gallons of water, to. which was added 10 per cent 
crude petroleum, were not quite satisfactory, as it was hoped that the 
combination would prove more effective as an insecticide and less 
injurious to the trees than either substance separately in the usual 
proportions. This year both 10 and 15 per cent of the crude petroleum 
obtained from the Standard Oil Company were used in combination 
with the pound to 4 gallons solution of whale-oil soap. There was no 
perceptible injury to the trees in either case, and the San Jose seale 
was pretty thoroughly checked with both mixtures, the one with the 
higher per cent of oil giving on the whole the best satisfaction. 
The results obtained with whale-oil soap solutions, both 1} and 2 
pounds to the gallon, were up to date practically the same as those of 
last year. The scale was severely checked, but in no instance was it 
so thorough as where crude petroleum in some form was used. Two 
pounds to the gallon gave a little better result than the weaker 
solution. 
