Circular 21 - Insecticides and Subsidiary Materials 72 
Caution : Since sodium fluoride is 
poisonous if taken internally it should be put 
in tight containers, plainly marked "Poison," 
and kept in a dry, safe place away from foods. 
It is somev/hat irritating to the respiratory 
passages if the dust is inhaled. 
In New York City all sodiuia fluoride 
must be colored blue and the National Asso-> 
elation of Insecticide and Disinfectant Man- 
ufacturers Inc. has gone on record favoring 
this practice throughout the United States. 
Sodium fluoride may be purchased in 
small containers up to large 350 to 375 pound 
barrels. The barrels in carload lots cost 
from 84: to 9t cents per pound. 
Available on contract: see Class 51, 
General Schedule of Supplies, Procurement 
Division, Treasury Department. 
SPEAPJ\HNT OIL 
In the case of sandfly attack on the 
human body, spearmint oil is of some value 
as a repellent. 
Oil of spearmint is distilled from the 
fresh parts of the flov/erinj plant Ivlentha 
spicata Linne. It is a colorless, yellow or 
greenish-yellow liquid, havin^^ the character- 
istic odor and taste of spearmint. The price 
of oil of spearmint in drums is 32.55 to ;;?2.30 
per gallon. 
For manufacturers and distributors see 
numbers 1, 25, 34, 38, 50, and 7U of list at 
end of this circular. 
