U. S. D. A., B. E. Bui. 96, Part IV. T. C. & S. P. I. L, October 12, 1911. 
PAPERS ON INSECTS AFFECTING STORED PRODUCTS. 
CARBON TETRACHLORID AS A SUBSTITUTE FOR CARBON 
BISULPHID IN FUMIGATION AGAINST INSECTS. 
By F. H. Chittenden, 
In Charge of Truck Crop and Stored Product Insect Investigations, 
and 
C. H. POPENOE, 
Entomological Assistant 
INTRODUCTION. 
A representative of a chemical company in Baltimore, Md., sug- 
gested to the senior writer as early as 1905 the use of carbon tetra- 
chlorid (CC1 4 ) as a possible substitute for carbon bisulphid (CS 2 ), since 
the tetrachlorid is known to be noninflammable. A sample was kindly 
furnished and was thoroughly tested in the open and found, as claimed, 
to be noninflammable. No opportunity, however, was afforded at that 
time to make a detailed series of tests of its insecticidal properties. 
A druggist of Washington, D. C, also suggested the substitution 
of this chemical for carbon bisulphid, and as others had made similar 
suggestions a series of experiments was begun on a small scale at 
Washington, D. C., under the senior author's direction, by the junior 
author and bv Mr. D. K. McMillan. 
Carbon tetrachlorid, when pure, is a thin, transparent, colorless, oily 
fluid, with a pungent, aromatic odor — not powerful, however, as in 
the case of carbon bisulphid, and not nearly so disagreeable. It is 
manufactured by the combination, in a heated tube, of the vapors of 
carbon bisulphid and chlorine. It has a specific gravit}^ about one- 
third greater than carbon bisulphid, and is similar in other properties, 
with the exception of being noninflammable. 
There are records of experiments made with this chemical as a 
fumigant for nursery trees in 1908, but tests for stored products 
affected with insects were made more recently. One of the former 
records is by Dr. W. E. Britton, 1 who states that carbon tetra- 
chlorid was used at rates of from 1 to 8 ounces in a fumigating box 
containing 10 cubic feet of space, the fumigating period varying from 
2 to 6 hours. All scales were killed, and no trees were injured, where 
i Journ. Econ. Ent., vol. 1, p. Ill, 1908. 
53 
