Part IV.] R. S. Pearson: Antiseptic Treatment of Timber. 11 
TABLE III. 
Treated. ! Untreated. 
, Antiseptics with 
which the different 
species of timber were 
treated. 
i 
Number of j 
years under | 
observation. 1 
Number 
origin¬ 
ally 
laid 
down. 
Number 
remain¬ 
ing. 
Average 
durability, 
in years, j 
1 
Number 
origin¬ 
ally 
laid 
down. 
Number 
remain¬ 
ing. 
Average 
durability, 
in years. 
Cresoyle . 
j Yrs. mos. 
5 6 
12 
9 
Yrs. mos. 
5 2 
12 
3 
Yrs. mos. 
2 
Anthrol 
1 5 0 
I 12 
12 
5 0 
12 
3 
2 
Burma oil 
j 3 6 
12 
10 
3 4 
12 
5 
2 
Liquid Fuel 
j 3 6 
i 12 
10 
3 4 
12 
3 l 
1 
The results obtained so far with Cresoyle and Anthrol are quite satis¬ 
factory : of the specimens treated with the latter, none have failed up 
to date. The reason for this is due to the method of treatment, as also 
to the value of the oil. Of the experiments described so far, the treat¬ 
ment has consisted in either soaking the specimens for one hour in hot 
oil or in immersing the specimens for 10 or 15 minutes in a bath of cold 
oil. In the case of the specimens treated with Anthrol , the treatment 
was far more drastic, as they were immersed in hot oil for an hour and 
allowed to remain in the solution for a further period of 16 hours, while 
it cooled down, resulting in a complete penetration in the case of the 
soft-wood species and a fairly heavy absorption by the harder timbers. 
This experiment demonstrates the possibility of preserving even the 
softest timbers, such as Boswellia serrata, Bonibax malabaricum and 
Odina Wodier for five years and more with a creosote oil. 
Turning to the oils with a petroleum base, it will be seen that they, 
too, protect timber, for though their toxic value is low, their water¬ 
proofing properties are considerable, while they render the timber dis¬ 
tasteful to white-ants. The experiments with Burma oil and Liquid 
Fuel have not as yet been long enough in progress to enable one to form 
a definite idea as to their value, though it is thought that the results 
obtained will be less satisfactory than those obtained with Coal-tar 
creosotes. The results with Burma oil and Liquid Fuel based on either 
their average durability or the number of specimens remaining after 
three and a half years, are exactly equal. 
(iv) Fourth group of Laboratory Experiments. 
Experiments carried out with Atlas solution, Bellit, Sodium Fluoride 
and Chloride of Zinc and Hylinit. 
The experiments dealt with up to this point have all been carried 
out with oils derived from Coal-tar or from a Petroleum base. This 
[ HI ] 
