14 BULLETIN 1312, U. S. DEPARTMENT OF AGRICULTURE 
SUMMARY 
The rate of loss of nicotine from nicotine sulphate dusts prepared 
with kaolin, kieselguhr, talcum, plaster of Paris, calcium hydroxide, and 
ealcium carbonate follows the order in which the carriers are given. 
Dusts made with free nicotine solution lose their nicotine 
much more rapidly than those made with nicotine sulphate. The 
effect of the carriers, however, is in about the same order in both 
cases. 
Canvas bags, pasteboard boxes, and paraffined boxes are un- 
satisfactory containers for nicotine dusts. Air-tight metal or glass 
containers only should be used for packing them commercially. 
The rapid loss of nicotine from plaster of Paris-nicotine sulphate 
dusts was no doubt due to the presence of calctum carbonate as an 
impurity in the plaster of Paris used. 
-Nicotine sulphate solutions became concentrated to about 45.5 
per cent nicotine, owing to evaporation when they were exposed 
to the air at room temperature, but with little or no loss of nicotine. 
Under the same conditions, solutions of free nicotine lost, in addi- 
tion to water, from 10 to 17 per cent of the nicotine originally present, 
and reached a concentration of 89 per cent nicotine, which remained 
unchanged under the conditions of the test. 
LITERATURE CITED 
(1) CAMPBELL, R. E. 
Notes on nicotine dust progress. In J. Econ. Entomol. (1923), 16: 
497-505. 
(2) Ds Ona, E. R. 
The relation between the volatility and toxicity of nicotine in sprays and 
dusts. In J. Econ. Entomol. (1923), 16: 486-493. 
(3) Heapueez, T. J., and Rupotrs, WILLEM. 
Some further experience with contact dusts. Jn J. Econ. Entomol. (1922), 
15: (58h 
(4) 
Some principles which underlie the making and use of nicotine dust. 
N. J. Agr. Exp. Sta. Bull. 381 (1928), 47 pp. 
(5) Rupoitrs, WILLEM. 
Nicotine delivery from dust carriers. In J. Econ. Entomol. (1922), 15: 
421-424. 
(6) SmirH, Raupu E. 
The preparation of nicotine dust as an insecticide. Calif. Agr. Exp. Sta. 
Bull. 336 (1921), 14 pp. 
(7) TuatcuEer, R. W., and Streeter, Leon R. 
Factors which affect the volatility of nicotine from insecticide dusts. 
N. Y. Agr. Exp. Sta. Bull. 501 (1923), 34 pp. 
