Circular 21 - Insecticides and Subsidiary Materials 61 
fabric or neoprene-treated gloves and aprons 
should be used to protect the body. Its dust 
causes sneezing. 
Pentachlorophenol may be bought in 
drums at 20 to 25 cents per pound. 
For manufacturers and distributors 
see numbers 36 and 76 of list at end of this 
circularo 
PETROLATUL'I 
In the semisolid form of carbolated 
petrolatum or carbolated vaseline this material 
is useful for the relief of flea and chigger 
bites when applied to the affected area of the 
skin. The liquid petrolatum designated as 
white mineral oil or liquid vaseline is used to 
prepare a mosquito repellent by mixing v;ith 
pyrethrum extract. 
Petrolatum is a neutral, practically 
odorless and colorless, grease-like, oily sub- 
stance which is derived from petroleum by dis- 
tilling off the lighter portions and purifying 
the residue. Several forms of petrolatum are 
available commercially, the semisolid, yellow 
form, and a colorless or faintly yellow liquid 
known as liquid petrolatum, liquid paraffin, 
white mineral oil or paraffin oil. The semi- 
solid form is used as a carrier for medicants, 
the liquid as a lubricant for the intestinal 
tract, in sprays for the nose and throat, and 
in hair dressing. Petrolatum preparations of 
many kinds are sold under the trade name of 
vaseline. 
Petrolatum is marketed in iVOO-pound drums, 
1- to 50-pound cases of cans, the drums costing 
