370 
Philippine Journal of Science 
1919 
TEST OF THE RESISTANCE OF CAMPHOR GREEN OIL TO TERMITE ATTACK 
As supposed in the beginning, camphor green oil really con- 
tains sesquiterpene alcohol, which is said to be effective in 
preventing the attack of termites. In order to prove its effect 
practically, the following tests were carried on: 
Experiment 1. — Camphor green oil, roughly fractionated in 
the Monopoly Bureau, was injected into Japanese pine by means 
of full process. The blocks (2 by 2 by 15 inches, or about 
5 by 5 by 38 centimeters) were buried in ground infested by 
Coptotermes formosanus with several control pieces (untreated 
pine). The controls were seriously attacked within five to seven 
days (Plate XI, fig. 2, a, b), while the treated blocks remained 
unattacked for about one year (Plate XI, fig. 2, c). 
It is obvious that camphor green oil is effective in preventing 
the attack of termites. However, it is very expensive, if the pure 
oil is used. As shown in Table XXVI, the amount of oil produced 
in the Monopoly Bureau is not sufficient for treating all the 
timbers used in Formosa. 
Table XXVI. — Camphor green oil produced by the Monopoly Bureau. 
Year. 
Pounds. 
1912 
44,562 
1913 
23,491 
1914 
28,397 
Containing only 1.04 per cent of volatile oil, cypress pine 
is highly resistant to termites. Foochow cedar, more or less 
resistant to termites, contains 4.6 per cent of volatile oil. It 
seems reasonable to expect, therefore, that a small amount of the 
camphor green oil may be effective in preventing damage. If 
this is true, we can economize the green oil by using a small 
amount, instead of a large quantity as in the case of creosoting 
(5 to 6 gallons per cubic foot, or 18 to 22 liters per 0.028 + 
cubic meter, of timber). 
To use the camphor green oil practically, it is necessary to 
employ a method of treating timbers at the lowest expense, 
injecting only a small amount of the oil. In order to determine 
the limit of the amount of oil that is effective in preventing 
damage, the following experiment was made: 
Experiment 2. — Camphor green oil was dissolved in 90 per 
cent ethyl alcohol, making 1, 2, 3, 5, and 10 per cent solutions. 
After injecting each solution into Japanese pine (2 by 2 by 15 
inches, or about 5 by 5 by 38 centimeters), the alcohol was 
