307 
April, ’24] guyton: chlorine gas 
foothold. The larva slowly wears itself out and died before it is able to 
penetrate. 
Unfortunately the above recorded data fails to show clearly just why 
Milltown Ball Clay No. 9 exerts a destructive effect when not in im¬ 
mediate contact with the larvae or pupae of the bean weevil and an- 
goumois grain moth. So far as the writer can see, there is nothing in the 
known chemical or physical composition of Milltown Ball Clay No. 9 
that would account for its ability to destroy immature forms of the 
common bean weevil or angoumois grain moth, when not in contact with 
them, except possibly radio-activity. The material is somewhat radio¬ 
active. 
Effect of this material upon germination or upon the milling and bak¬ 
ing has not been determined. 
Mr. H. F. Dietz: I would like to ask if this treatment has any effect 
on the milling quality of the wheat? 
Mr. T. J. Headlee: None that we can determine. 
Vice-President S. B. Fracker: The next paper is by T. L. Guyton. 
NOTES ON THE USE OF CHLORINE GAS AS AN ' 
INSECTICIDE 
By T. L. Guyton, Penna ., Bureau Plant Industry 
Trials in the use of chlorine gas as an insecticide in the control of the 
Angoumois grain moth (Sitotroga cerealella) resulted in the loss of ger¬ 
mination to the treated wheat and an incomplete kill of the moths. 
In one case where the grain had a moisture test of 17% the treatment 
resulted in the charring of the treated sample. 
An agent of the Electro Bleaching Gas Company called the writer’s 
attention to the possibility of using chlorine gas as an insecticide in 
the control of the Angoumois grain moth and offered to furnish a tank of 
the gas for trial. 
On December 1922 some wheat was obtained in the vicinity of Carlisle, 
Penna., just as it came from the thrashing machine, and another sample 
was obtained from a flour mill nearby. The sample obtained from the 
thrashing machine was heavily infested with the moth. The wheat 
weighed only thirty-six pounds to the bushel, had a moisture content of 
seventeen per cent and a germination test of sixty-nine per cent. The 
wheat from the mill weighed fifty-six and three-tenths pounds to the 
