Circular 21 - Insecticides and Subsidiary Materials 59 
Caution : Food substances, including 
grains, exposed to the fumes of the chemical 
may retain residues that render them unfit 
for consumption. Therefore it should never 
be used to fumigate such materials. 
This chemical is shipped in carload 
lots at 11 to 12 cents per pound, in less 
than carload lots at 12^ to 13^ cents per 
pound, in 25- to 200-pound barrels, 150-pound 
drums, and 1- to 5 -pound cans. 
Available on contract: see Class 51, 
G-eneral Schedule of Supplies, Procurement 
Division, Treasury Department. 
PARIS GREEN 
This bright green arsenical compound 
is used to kill malaria-carrying mosquito 
larvae when applied as a dust to the surface 
of the water. The dust is prepared by mixing 
the poison with a carrier like talc, 
diatomaceous earth, or lime. 
Paris green, which is chemically 
acetoarsenite of copper (3Cu(As02)2«Cu(C2H302)2> 
was one of the first stomach poisons used in 
America to destroy insects. It is a very 
poisonous, heavy, emerald-green powder and 
when used as a spray requires constant agita- 
tion to keep it in suspension. Commercial 
paris green should be ^^round finely, should 
contain not less than 50 percent of total 
arsenious oxide, and not more than 3i percent 
v/ater soluble arsenic oxide. 
Caution: Paris <2^reen is extremely 
poisonous and therefore should be kept in a 
