49 Farmers’ Bulletin 1128. 
in the full quantity of water, with occasional stirrings, for a period 
of 24 hours. About 70 to 80 per cent of the nicotine will be ex- 
tracted. After straining the tobacco solution to remove the parti- 
cles of leaves and stems, it is ready for use. 
The tobacco spray may also be made in a lime-sulphur plant 
equipped with steam. Place the proper amount of tobacco and water 
in the cooker and release the steam, and, as soon as the water reaches ~ 
the boiling point, shut off the steam. As soon as the solution has 
cooled it is ready to use. By this method about the same percentage 
of nicotine is extracted as by the soaking process. The solution 
should never be boiled, as the nicotine is volatile. 
Nicotine sprays should not be made up until they are to be used, 
since fermentation begins within two or three days, perhaps spoiling 
them for spraying purposes. 
The homemade nicotine solutions, when prepared as above at the 
strengths indicated, will give control of most aphids. But as a mat- 
ter of precaution it will be advisable to observe the effect of the 
spray upon the insects, and, if not effective, to strengthen it. 
Tosacco Dust. 
Tobacco dust has long been recommended for the contrcel of the 
woolly apple aphis on the roots of the apple, and for other root- 
inhabiting insects, and to a less extent for dusting low-growing 
plants, as currants and gooseberries for the destruction of aphids. 
Tobacco dust has some value as a treatment for the woolly aphis on 
the roots of the apple, its effectiveness varying much with the amount 
of nicotine in the dust and its fineness and the character of the 
weather. Abundant moisture in the soil, as from irrigation or rains, 
leaches out the nicotine, thus destroying the insects to a greater or 
less extent. Where tobacco dust may be obtained cheaply its use 
is warranted for the woolly aphis, but the purchaser- should insure 
himself that the dust is not the grade sold for fertilizer purposes 
from which the nicotine has been extracted. In addition to its 
insecticidal value, tobacco dust has a distinct fertilizer value. 
SOAP SPRAYS. 
Sprays made from several kinds of soap are much used for the 
destruction of various soft-bodied sucking insects, particularly aphids, 
the pear psylla, certain plant-bugs, ete. 
COMMERCIAL FisH-O1L SOAps. 
The commercial fish-oil soap, formerly known under the trade 
name of ‘‘whale-oil soap,” is usually made from fish oils combined 
with either caustic soda or potash and should contain not over 30 
per cent of water. An average grade of a soda fish-oil soap should 
