32 
INSECTS NOXIOUS TO AGRICULTURE. 
The object of the milk is not only to lessen the 
injurious qualities of the kerosene, but also to induce 
it to mix more freely with the water; but it is the 
oil alone. which destroys the insects and their eggs. 
(c.) Kerosene and soap. When milk is not obtain- 
able, or too dear, nothing is so excellent as this mix- 
ture. Soap itself (see below) is a useful insecticide, 
and in combination with kerosene includes the good 
qualities of both substances. The cheapest possible 
qualities of soap will do. ‘The mixture, which 1s, 
even more than the last, purely mechanical, must be 
made first of all an “emulsion.” The American 
experiments result in the following recipe and method 
of using :— 
Formula : 
Common soap ... a -asn pbb, 
Kerosene ae ast oe) ea@alls, 
Soft water we 1 gall. 
Dissolve the soap in the me yen ee to boiling, 
then add the kerosene, and churn the mixture until 
a creamy fluid results which thickens on cooling. 
Dilute with nine or ten times the quantity of water : 
the quantities given above will make about thirty 
gallons of liquid. Whale-oil soap, soft-soap, or any 
other kind will do. As with the milk emulsion, 
apply in the form of the finest spray for evergreens 
(Riley ; Hubbard ; Personal experiment). 
(d.) Kerosene and oil. Castor-oil, limseed-oil, whale- 
oil, may be used. A mixture of this kind, in the 
proportion of 1 part kerosene to 3 or 4 of oil, has 
been found very efficacious for apple- and other fruit- 
trees attacked by the common apple-scale (Myt. po- 
morum). But, as observed above, the mixture must 
not be laid. on too thick. Thinly brushed all over. 
trunk and branches, at dead of winter, it has been 
found quite successful in destroying both imsects and 
eggs, without injury to the trees (Personal experi- 
ment). It would probably not answer for evergreens, 
on account of expense. 
On the whole, it may be said that, as far as cer- 
tainty can be attained in the matter, there is no sub- 
