22 
FUMIGATION FOIl THE CITRUS WHITE FLY. 
.Mis('].i.r.A.\i:ors requirements. 
According to the method of procedure hereinafter described and rec- 
ommended for use in fumigating for the white fly, when an outfit of 
more than four or five tents is in use, a cart or stone drag and a horse 
may be desirable for carrying the materials from tree to tree. An 
ordinary hand push-cart can be recommended as convenient for use 
in some cases. When a horse or a hand push-cart is not available, a 
box-like tray (PI. IV, fig. 1) with handles should be constructed. 
This should be large enough to contain a supply of acid and cyanid 
for all of the trees covered at one time by the set of tents in use. One- 
half of the tray should be reserved for as many 3-quart pitchers as 
may be needed and for the graduate, and the 
other half should be provided with compart- 
ments for the bags of cyanid, if weighing is 
done by day, or an open box for the loose 
cyanid if the weigliing is done as each tree 
is fumigated. A torch should be fixed over 
the center of the tray, and if the cyanid is 
weighed as used there should be a strip of 
board across the tray to serve as a platform 
for the balances. Balances are preferable to 
spring scales for use in weigliing the cyanid. 
They should not be larger than necessary for 
weigliing 40 ounces of cyanid at once. For 
containing the acid temporarily, stoneware 
churns of a capacity of 3 or 4 gallons are 
much used in California, and can be recom- 
mended for use in Florida. Frequently sev- 
eral 3-quart.pitchers are more convenient than 
the stoneware churns. A measuring glass of 
16 ounces capacity is needed for measuring 
the acid, and an extra measuring glass should 
be provided for use in case of breakage. The 
acid is dipped into the measuring glasses by 
means of a long-handled enamel-ware dipper, or poured in from a 
pitcher. For carrying water a couple of large pails are needed. 
The one who measures the acid and generates the gas should be 
provided with rubber gloves of good quality and long enough to 
cover the wrists well, or even the entire forearm. For generating the 
gas, earthernware jars from 1J to 5 gallons capacity are necessary, 
according to the size of the trees and dosage required. Extra jars 
should be provided to obviate possible inconvenience in case of break- 
age. Cylindrical jars are preferable to those which narrow at the to]). 
as the chemicals are much more likely to boil over in the latter than in 
the former. The cyanid. after being weighed, may be put into paper 
Fig. 3.— Plan for schedule board, 
showing convenient arrange- 
ment: A, space for resting lan- 
tern temporarily; B, scratch 
pad; C, dosage table; D, dia- 
gram of grove. (Original.) 
