Circular 21 - Insecticides and Subsidiary Materials 80 
and other resinous woods, by steam or other 
distillation methods, or by extraction with 
solvents. It is knov/n also under the names 
of oil of turpentine, v/ood turpentine, wood 
spirits of turpentine, and gum spirit. 
Caution ; Turpentine is very inflamma- 
ble and clothes saturated with it are a 
frequent source of fire in buildings. 
Steam distilled turpentine is marketed 
in tanks, 30- to 50-gallon drums, 1- and 5- 
gallon cans. In tanks it sells for 66 cents 
per gallon; in drums the material costs from 
58 to 71 cents per gallon in carload lots. 
In less than carload lots the price is 74 
cents per gallon. 
Available on contract: see Class 52, 
General Schedule of Supplies, Procurement 
Division, Treasury Department. 
VINEGAR 
In the treatment of head lice a mixture 
of equal parts of vinegar and kerosene may be 
applied directly to the infested hair. Hot 
vine,sar alone is also used to kill the e^sS. 
ro' 
Vinegar is dilute impure acetic acid 
(C9H/O2), a sour liquid used as a condiment 
or~as a preservative. It is obtained by the 
acetic acid fermentation of dilute alcoholic 
liquids. Cider and malt are very common 
sources but it maj'' be made from the fermented 
Juice of nearly any fruits. Vinegar is so 
well known that it needs no further discussion 
here. 
