- 467 - 
Recent studies of nicotine as an insecticide have shown that 
the toxicity curve of nicotine in solutions is almost an exact 
parallel of its volatility curve; Levorotatory nicotine (free 
nicotine) is volatile and more toxic than the non-volatile, dextro- 
rotatory form (nicotine salts). Reduced efficiency then may 
result from two reasons: (a) the use of non-volatile nicotine 
salts, such as nicotine sulphate with insufficient alkali to 
free the alkaloid from the combining acid; (b) the volatiliza- 
tion or oxidation of nicotine from ground tobacco which is being 
used as a vermifuge. 
The same correlation between volatility and toxicity was noted 
in dust mixtures. 
FULMEK, L. (2020) 
1924(?) NOTES ON THE APPLICATION OP INSECTICIDES AND FUNGICIDES TO 
DELI TOBACCO. Deli Proefst. Vlugsohr. 29, 4 pp. 
[Abstract in Rev. Appl. Ent. (A) 13:223. 1925.] 
The contact insecticides used in Deli, Sumatra, against tobacco 
pests include kerosene-soap emulsion, nicotine, and derris. The 
addition of 0.3 to 0.5 percent soap to solutions of the last two 
is advised. 
LESS, A. H. (2021) 
:x 
1924. EGG-KILLING WASHES. Jour. Pomology and Hort. Sci . 3(4) .-174-178 
[Abstract in Rev. Appl. Ent. (A) 12:252-253. 1924.] 
Combinations of caustic soda and nicotine had strong killing 
power is applied just before hatching but were useless at an 
earlier data. 
BOURCART, E. (2022) 
1925. INSECTICIDES, FUNGICIDES, AND WEED KILLERS. London, 2d Ed. , 
pp. XII, 431, illus. 
This translation from the French gives a fairly good view of 
nicotine as an insecticide (pp. 394-404). The green leaves of 
Nicotiana tabacu m and N. rustica L. contain 1.5 to 9 percent of 
nicotine, the dry leaves up to 4 percent. In France the culture, 
manufacture, and sale of tobacco are the subject of a monopoly 
exploited by the State. The French tobacco administration 
delivers the tobacco juice with up to about 10 percent of 
nicotine, which enters into many insecticides to strengthen 
their action. 
The following headings are discussed: Insecticides with a. 
tobacco basis, properties of nicotine, its action on plants, 
its action on insects, its use as r fumigant in closed spaces, 
and its use in the open air, which briefly discusses nearly all 
forms of tobacco insecticides, including nicotine dusts. The 
names of dozens of insects are also given. 
