FUMIGATION OF CITRUS TREES. 
23 
inches and prevents the slopping of acid through the hole. A lead- 
lined cover fits into the top of this tube. This opening in the cover 
is for use in filling the jar. Very few metals will withstand sulphuric 
acid without corroding. For this reason all the common types of 
faucets are practically worthless for drawing acid. In fact there is 
no faucet on the market that is altogether satisfactory for this pur- 
pose. A manufacturing firm on the Pacific coast has experimented 
extensively along this line, but without any marked success. This 
difficulty has been met in an entirely practical manner by attaching a 
three-quarter-inch copper or iron pipe to the lower side of the jar and 
regulating the flow of acid by means 
of a large pinchcock placed on a short 
piece of rubber tubing at the end of 
the pipe (fig. 5, 1 , 4, and 5) . The flow 
of acid is rapid and easy to control. 
Pure rubber is most satisfactory, and 
a fresh piece should be substituted 
about every other night. 
The water is drawn from a faucet. 
In order "that this may be drawn on 
the same side of the cart as the acid, 
an elbow pipe of the character shown 
in Plate IV, figure 1, is required. The 
faucet should have an opening of about 
three-fourths inch to allow a heavy 
flow, and should be of such a type that 
a half-turn will give it a full opening. 
As fumigation is usually conducted 
at night, a torch is placed on the 
front of the cart to furnish a light by 
which to measure the acid and water ; 
another, on the elevated platform, is 
convenient for the man weighing the 
cyanid. 
This style of cart is entirely practicable for almost all fumigation 
work. The chemicals can be measured quickly and accurately with- 
out any slopping of acid or water. A glass graduate with a capacity 
of 16 or 32 ounces, preferably the latter, is essential for measuring 
acid and water. A kind having elevated rings in the glass has been 
found most satisfactory for night work. The man handling the acid 
should wear rubber gloves. Cotton gloves are convenient for hand- 
ling cyanid. 
Some fumigators have preferred to use a horse-drawn wagon 
equipped for carrying the chemicals rather than a handcart. This 
has resulted in a number of very original combinations. The most 
67330°— Bull. 90—12 3 
Fig. 5. — Earthenware acid jar with attach- 
ments for field use; 1, Jar complete; #,inside 
view of lead-lined cover showing tube at 
center; 3, copper top for opening in cover; 
A, pinchcock; 5, method of attaching iron 
pipe to jar, and rubber tube on end of pipe 
with pinchcock attached. (Author's illus- 
tration.) 
