- 461 - 
The optimum efficiency of sprays containing nicotine sulphate 
and fish-oii soap was reached with a definite degree of concentration, 
while solutions of greater or less concentration were less effective 
as insecticides. The addition of nicotine sulphate to fish-oil soap 
solutions decidedly increases their value as insecticides, while the , ... 
efficiency of nicotine sprays is also increased "by the addition of soap, 
out when more than 4 11). of soap were used with 10 oz. of nicotine 
sulphate to 50 gal. of water, there was a loss of "both wetting power 
and efficiency. A chemical change probably takes place when a certain 
concentration is reached. It is evident from the relative efficiency 
of the sprays that this chemical reaction affects the soap and not the 
active nicotine sulphate. 
The most satisfactory results were obtained with formulae con- 
taining 5 lb. of soap and 6-l/2 to 8-3/4 oz. of nicotine sulphate to 
50 gal. of water. TChen more than 8-3/4 oz. of nicotine was added, there 
was a loss in both wetting power and efficiency. 
V., S. (1997) 
1916. ON THE REPLACEMENT OF QUASSIA 3Y TOBACCO. Eruit Growing, Petro- 
grad, 27(8-9):' 378-379. [In Russian. Abstract in Rev. Appl . Ent. (A) 
4: 495. 1916.] 
As a substitute for quassia decoction and soap, tobacco and soap 
may be used, 1 lb. tobacco leaves being boiled in 3 gal. of water to which 
l/2 lb. of soap is subsequently added. The tobacco extract may be pre- 
served by adding 1 g. of salicyclic acid to each pt . For use, 5 to 10 
lb. of the extract is dissolved in 30 gal. of water, 5 lb. of soap being 
added. 
ANONYMOUS (1998) 
1917. LA NICOTIANA. Ri vista, di Agricoltura 23: 664. 
The following spray mixture is recommended in Portugal: 1 to 2 
g. pure nicotine, 200 g. sodium carbonate, lOCOg. black soap, 1 1. de- 
natured alcohol, and 100 1. water. 
BENTLEY, G. M. (1999) 
1917. SUGGESTIONS FOR THE CONTROL OF INJURIOUS INSECTS AND PLANT DISEASES, 
leant Agr. Expt. Sta. Bull. 117, pp. 111-123, illus. 
:"< 
Directions are given for the preparation of homemade tobacco 
solution. Factory-made tobacco solutions are sold under various trade 
names and contain 10, 20, 30, and 40 percent of nicotine by weight . 
Tobacco, dust, snuff, or warehouse sweeping can be used with partial 
success against the root aphid (p. 119) . 
Nikoteen is used for fumigation. Put l/7 oz . of it in 5 oz. 
water and place this mixture upon a hot steam pipe and let it vaporize 
at night. This amount is sufficient for a space of 1,000 cu. ft. (p. 121) 
