374 Philippine Journal of Science is»i» 



With the control, blocks injected with pure Niizu neutral oil, 

 the results shown in Table XXXII were obtained. 



Table XXXII. — Japanese pine blocks injected with pure Niizu neutral oii. 



Total blocks 4 



Damaged : 



Number 2 



Per cent 50 



Dry rot: 



Number 2 



Per cent 50 



Notwithstanding the fact that Japanese pine is most liable 

 to the attack of termites, the blocks treated with the neutral 

 oil remained unattacked after the lapse of more than two years. 

 As the controls were attacked by the termite and fungus as 

 well, it is clear that the green oil is an essential factor in 

 preventing the damage. The mixture of Niizu neutral oil and 

 the green oil (10 per cent solution) costs about 5 cents per 

 gallon. Its color is pale yellow, and it gives no stain to timbers ; 

 its odor is pleasant, being similar to the characteristic fragrance 

 of camphor; it is nonpoisonous to human beings; it is not volatile 

 under ordinary temperature. Thus, this solution seems satis- 

 factory as a preventive against the attack of termites. 



Volatility of camphor green oil. — Twenty grams of camphor 

 green oil were weighed in an absorbing vessel with special 

 glass tube. The vessel was connected to a gasometer that was 

 joined to a water pump. Air was pumped into the absorbing 

 vessel and from time to time the amount of the oil was measured. 

 The experiment was carried on for twenty-eight days (at 22 f 

 to 28° C). 



Table XXXIII. — Showing volatility of camphor green oil. 



Decreased amount 

 Volume of air. of the oil. 



Liters. per cent. 



250 4.11 



500 5.37 



750 5.90 



1,000 6.08 



Saturated with 1,000 cubic centimeters of the air, the loss 

 of the green oil was estimated to be 6 per cent of the original 

 volume. It is probable, therefore, that the green oil will remain 

 almost permanently, even when used in the open air. 



