DOSAGE REQUIREMEH rS. 
Table VII. Study of doaagt rates. 
\:> 
i: ktio of 
\lllotlllt 
Rate Number oubio 
square feet 
CJ :iliul BSl i- 
(eel •■!" 
space per 
in leakage 
Amount of 
Percenl of 
mated :is 
ounce ol 
yanid. 
.surface to 
cyanid 
w hlte tin s 
necessary 


cubic feel 
used. 
deal royed. 
for 
Esl imated 
of 
successful 
i ed. 
;is 
contents. 
results. 
necessarj . 
liners. 
Ouna 8. 
i :2.6fi 
'_'.") 
<>'.>. 2 
■ii 
171 
l.V.t 
1:2.66 
301 
98. l 
34 
171 
17.7 
1:_*. 49 
-V.! 
98. 9 
29 
L60 
IK, 
1:2.38 
30j 
98.6 
x\ 
L80 
1 11 
1:2.30 
17; 
97 
20 
•JUT 
L79 
1 : 2. 29 
ok 
97.6 
28 
127 
L08 
1 : 2. 28 
1M 
98.6 
lit 
1 is 
128 
1:2. 17 
12 J 
99. 7. 
11 
11'. t 
133 
1:2.09 
•_'l T . 
99. 7 
27 
l.M 
138 
U2.09 
28J 
99. 6 
30 
130 
L24 
1:2.08 
1.") 
99. s 
L6 
126 
lis 
1:2.01 
17', 
98.8 
•jo 
IS!) 
L83 
L:1.96 
■ >■> 
99.5 
24 
154 
ill 
1 : 1 . ss 
24j 
99.5 
27 
l.iii 
IIS 
1:1. ss 
20l 
97.7 
•.'•I 
lis 
127 
1:1. 83 
13* 
99.8 
15 
154 
L38 
1:1.83 
i;u 
95.7 
17 
l 16 
L22 
1:1. 17 
Si 
97 
11 
152 
118 
From a study of the data in the Table VII the writer concluded 
that lor a ratio of 1:1.5 the cyanid should be used at a rate very 
near to 1 ounce to 110 cubic feet of space. Owing to the fact that 
in all cases tented trees include less inclosed space than would a 
regular figure which for purposes of approximate calculations has 
been considered as equivalent, this rate would be higher for a reg- 
ularly shaped inclosure whose cubic contents could be definitely cal- 
culated. Probably 1 ounce to 100 cubic feet of space is nearer the 
actual rate which the experiments indicate is necessary with the ratio 
mentioned. This, however, is of little consequence in dealing with 
sheet tents, for only the comparative volumes and dosage rates for 
trees of different dimensions are required for practical purposes. 
Having decided upon the adoption of 1 ounce of potassium cyanid 
per 1 10 cubic feet of space with the ratio of 1:1.5, calculations were 
made for tents with different ratios up to 1:3.6. Professor Gossard 
reports that 1 ounce to 170 cubic feet of space destroys all white 
fly pupa 1 in an air-tight fumigatorium. Considering that this rate 
i- approximately correct, an equivalent rate for the volume inclosed 
by a sheet tent covering a tree would be more than 170 cubic fed in 
the ideal form of inclosure upon which the calculations are based. 
Experiments numbered X.3 and X.4, however, show that a rate not 
Less than 1 ounce for \H\ cubic feet of space should be used when 
the ratio is 1 : 2. When the ratio is increased from 1:1.5 to I: infinity 6 
and the rate of dosage for this latter ratio is considered as 1 ounce 
a Fla. Exp. Sta. Bui. 67, p. 652. 
b It i< evident that if the aumbei of cubic feel of space were infinitely greater titan 
the number <>i" square feel of leakage surface, the rate "t" dosage required for an air- 
tight fumigatorium would be sufficient. 
