60 
Indian Forest Records. 
[Vol. III. 
Practically in no instance did the solution penetrate completely 
through the timber after immersion for 10 minutes, and as it most 
certainly would not do so were the timber under treatment of the size of 
a B. G. sleeper, the correct figures to take are those based on superficial 
absorption and not those calculated according to volume. 
The above figures must, however, be taken with extreme caution and 
can only be used as a rough guide to the cost of treating the various 
species of timber, the danger of accepting such figures as final is 
demonstrated by the case of Finns longifolia , the cost of treating which 
works out to £4*1 annas per B. G. sleeper. 
Estimates for oak and beech, based on Indian prices of Carbolineum, 
work out to about 7 annas for treating a B. G. sleeper, a by no means 
excessive rate as compared with Creosote. 
Further Experiments with Fipterocarpus Tuberculatus Timber. 
With a view to ascertain the period of immersion necessary for “ In " 
(Dipterocarpus tuberculatus ) timber in order to preserve it from decay, 
as also to determine the amount of the solution required for treating the 
timber, the cost at the same time being kept within working limits, 
a further set of experiments were carried out by treating cubes 
12" x3"x 3" in size, by immersion, during varying periods of time. In 
conjunction with the above tests another experiment was carried out to 
ascertain the excess amount of the antiseptic absorbed by allowing 
the timber to remain in the fluid while cooling down. Seven blocks of 
timber cut to exact size were prepared, the first was immersed for 15 
minutes in a hot solution of Avenarius Carbolineum , and allowed to cool 
in the fluid for another 45 minutes, the second was allowed to stay m a 
hot solution for an hour and then was removed, the third was heated for 
an hour and allowed to remain another hour in the fluid while it was 
cooling down; the fourth and fifth were similarly treated but allowed to 
remain for two hours and three hours respectively in the cooling solution ; 
the sixth was given 8 hours and the seventh 23 hours immersion over and 
above the hour in the hot fluid. 
The quantity of the antiseptic absorbed by [the various pieces works 
out as follows r— 
( 133 ) 
