24 MISC. PUB. 526, U. 8S. DEPT. OF AGRICULTURE 
tenite are most likely to give this effect. Those who experience 
difficulty of this kind should protect themselves by the use of a 
respirator provided with pads saturated with a solution of citric 
acid. 
Very acute illness can be caused by the absorption of nicotine 
through the skin. If concentrated solutions of nicotine are 
spilled on the skin, they should be immediately washed off with 
water. The operator should not continue working in outer cloth- 
ing which has become wet with nicotine-containing sprays, as the 
body will take up the nicotine from the clothing. 
NICQTINE BENTONITE 
Bentonite has the property of combining with nicotine to form a 
compound more resistant to weathering than other nicotine prepara- 
tions, and this compound has been used extensively on apples during 
the past few years as a substitute for lead arsenate in the control of 
the codling moth, and to some extent on grapes for the control of the 
grape berry moth. 
Nicotine when combined with bentonite may persist on fruit for 
2 or 3 months, though in amounts too small to be toxic to man. 
Tank mixtures are the cheapest and most effective but are more 
adhesive and may leave visible bentonite residues at harvest. 
An effective tank-mixed spray for use on apples during the cover 
spray period consists of— 
Nicotine*sulfate (40 percent) 222245 eee 1 pint. 
Wyomine: bentonites es = ee es Ge Pe eee eee 5 pounds. 
Crudeimaw Soy beansOllL2 2 he eee ee ee ee 1 quart. 
Web bere 3 Peo ens Se ee bot dt cae sn, ES ere ienes 100 gallons. 
Place about one-third of the water in the tank, add the nicotine 
sulfate, then add the bentonite slowly with strong agitation, followed 
by the soybean oil and the remainder of the water. Continue the 
agitation while spraying. 
An equally effective tank-mix nicotine bentonite, recently devel- 
oped, which leaves a much less conspicuous residue than the above for- 
mula, may be prepared by substituting 8 pounds of Mississippi ben- 
tonite for the Wyoming bentonite. If the Mississippi bentonite is used, 
2 quarts of a summer spray oil (see Mineral Oil, p. 20) may be 
substituted for the soybean oil when cheaper or more readily available. 
Proprietary nicotine bentonites are obtainable on the market. 
NICOTINE DECOCTIONS (HOME-MADE) 
For many years gardeners have used tobacco decoctions prepared 
in different ways. The most common method is to soak tobacco stems 
or high-grade tobacco refuse for 24 hours, stir occasionally, and use 
the liquid. It requires 1 pound of stems for each gallon of water to_ 
make a satisfactory spray. If high-grade refuse is used, less is re- 
quired—in some instances only one-fifth to one-tenth as much refuse 
as stems. The ready availability of commercially prepared nicotine 
extracts has rendered this method of obtaining nicotine almost obso- 
lete; see Nicotine, page 23. 
Tobacco stems are burned in greenhouses to produce smudges to 
kill aphids and whiteflies, but this method is not used very much 
nowadays. 
