Circular 21 - Insecticides and Subsidiary Materials 16 
odor. Medicinally it is used to destroy intes- 
tinal parasites, especially hookworms. Indus- 
trial uses included are as a fire extinguisher, 
as a dry-cleaning agent, and as a solvent for 
oils, waxes, rubber, and varnishes. 
Caution ; Carbon tetrachloride is toxic 
and similar to chloroform in its action on the 
human system. Exposure to it in enclosed 
places should be avoided. 
This chemical may be purchased in tank 
cars and drums at from 5 to 6 cents per pound. 
Small quantities are obtainable in bottles of 
various size. For prices of a mixture with 
ethylene dichloride see information given under 
latter material, page 29, 
Available on contract: See Class $1, 
General Schedule of Supplies, Procurement 
Division, Treasury Department. 
CAUSTIC SODA 
Caustic soda is used to wash garbage 
pails in connection with sanitary measures that 
are employed in the control of flies around 
army camps. 
Caustic- soda, NaOH, also known as sodium 
hydroxide, is available as white flakes, lumps, 
or rods. It is very caustic to tissue. It is 
soluble in water, alcohol, and glycerine. 
Industrially it is used extensively in various 
manufactures and processes. 
Caution: Since this material is very 
caustic it should be kept in tightly closed 
containers. Do not handle with bare hands. 
