Circular 21 - Insecticides and Subsidiary Materials 75 
One hundred pounds of sulfur in carload 
lots is priced at $2,80. In less than carload 
lots the same amount costs $3.25. 
Available on contract: see Class 51, 
General Schedule of Supplies, Procurement 
Division, Treasury Department. 
SULFURIC ACID 
This acid, H2SO, , is not an insecticide 
but is used in the ^ generation of hydro- 
cyanic acid gas from sodium (or potassium) 
cyanide as discussed in Circular 22 on fumiga- 
tion. For this purpose the technical grade 
having a specific gravity of 1.83 is satisfac- 
tory. (For a further description of hydro- 
cyanic acid gas, see the discussion under that 
heading. ) 
Sulfuric acid is a colorless liquid when 
pure but the commercial grades are yellowish or 
brov/nish due to the presence of certain impuri- 
ties. It is a heavy, oily-like, very corrosive 
liquid which has a great affinity for water. 
Industrially, sulfuric acid has probably more 
numerous uses than that for any other chemical. 
Caution ; Sulfuric acid is highly corro- 
sive and will burn the skin, clothing, and many 
materials, Vflien diluting , always pour the acid 
slowly into the water , never attempt t o pour 
the water into the acid . Keep in a safe'place, 
in tight glass containers, plainly labeled and 
marked "Poison.'* 
It can be purchased in 11-gallon glass 
carboys (I84 pounds) at 6-j to 8 cents per pound. 
In 9-pound bottles the price ranges from 15i to 
17 cents per pound. 
