DOSAGE TABLE. 67 
sides of the tent. II' the onl) available tents arc of inferior quality and 
fall short of being a> aearly gas-t ight as t he best of material, increases 
in dosage may be advisable. When it is desired to Fumigate with a 
thoroughness approaching extermination, an increase may be made 
of From K) to 25 per cent. Such a course is frequently advisable to 
check the Further spread of the fly in newly infested localities or in 
newly infested groves. In the Fumigation ^\' yery small trees, 20 feet 
over or less, there seem to he certain Factors sometimes interfering 
with efficiency which have not so Far been thoroughly investigated. 
It is possible that in the 4 using oi' crocks of 2 or .') gallons capacity For 
doses less than 5 ounces the mixture of acid and water Fails to gen- 
erate sufficient heat to cause quick chemical action, the heat absorbed 
by the jar being the disturbing factor. This may be partly obviated 
by using powder or very small lumps of potassium cyanid when the 
Ai»v is 5 ounces or less, but it seems advisable also to increase the 
amount by one-half or three-fourths above the recommended dose. 
If the size i^( the crock and consequent undue loss of heat is the prin- 
cipal disturbing factor, future experience may show that it is desirable 
to have on hand for use in fumigating very small trees a supply of 
half-gallon crocks or 1 -quart stone chinaware pitchers. 
In the table the amount in each case represents the next half ounce 
above the dosage which the detailed estimate calls for, whenever this 
dosage was more than one-tenth ounce above the even ounce or half 
ounce. For example, when the detailed calculation calls for 19.2 
ounces the number in the working table is 19t ounces, and when For 
19.7 ounces the number is 20 ounces. In using the table in the field, 
when the reading on the graduated tent shows the approximate dis- 
tance over the top to be an odd number of feet, the next even num- 
ber above should be selected. In the same way, when the exact cir- 
cumference is not shown at the top of the table, the next highest 
number should be selected. 
To illustrate the method of using the table of dosage, the Following 
examples show the measurements and dosage called for in the case 
of five trees of various sizes: 
Measurements of, and dosa<j< f<>r each of jive ir<,s of various sizes. 
Distance 
Circumfer- 
Amount <.l" 
over tented 
ence "i 
cyanid 
called lor. 
t ree. 
tented 1 ree 
Feet. 
/■• • 
Ouii' 
28 
15 
10 
i^ 
CD 
34 
:,i 
68 
47 
80 
71 
61 
72 
80 
89 
At all times it should be borne in mind that it is advisable to use 
one-half or even 1 ounce more than called For by the table rat her than 
the smaller amount. 
