28 
Bulletin 71. 
Dilute with water as in the preceding formula. If sweet milk 
is used add a little vinegar. Otherwise it may be impossible to form 
a stable emulsion. 
16. KEROSENE AND CRUDE PETROLEUM. 
These oils are used pure, and also diluted with water, tor the 
destruction of scale and other insects. Experiments in the Eastern 
States seem to indicate that the safest time to apply is early in the 
spring, just before the buds swell, and on a bright, windy day when 
the oil will evaporate rapidly. It seems that when applied in mod¬ 
eration, in the proporiion of 40 parts of the oil to 60 of water, these 
substances will seldom injure apple, cherry or pear trees, but can 
hardly be applied to tenderer trees, such as peach and plum, with¬ 
out farther dilution. 
When diluted with water in the form of a spray they may be 
used upon foliage of most plants, without injury, in the proportion 
of one of the oil to five or six of water. Most plant lice are killed 
in mixtures as weak as one to fifteen or twenty. 
Pumps are now made for the purpose of mixing the oil and 
water in the form of a spray, and so doing away with the need of 
preparing an emulsion. The one who has the insecticides to apply 
must decide whether or not he will go to the extra trouble of mak¬ 
ing the emulsion or whether he will go to the extra expense of 
purchasing a special and somewhat more costly pump. 
17. GASOLINE. 
This oil is also destructive to insect life. Its chief use is for the 
destruction of bed-bugs. It is applied pure by means of an oil-can 
or hand atomizer. To be effectual the bugs must be thoroughly 
treated with it. As it is inflammable, care must be taken not to 
bring fire near until the apartments where it is used are well aired. 
18. TURPENTINE. 
Turpentine is used for the same purposes as gasoline and the 
same precaution applies. 
19. LYE AND WASHING SODA. 
These substances are in considerable popular favor for the 
destruction of insects, but the writer’s experience with them has not 
been encouraging. In the proportion of a pound to three gallons of 
water they may be used upon the trunks of trees and will kill soft- 
bodied insects that might be wet by them. To be used upon 
foliage they should be diluted to a pound to forty gallons of water, 
and in this strength they will only destroy the tenderest of insects. 
Kerosene emulsion or whale-oil soap are much more effectual 
insecticides. 
