Part II.] Pearson: Antiseptic Treatment of Timber. 99 
Owing to the altered conditions under which it is now possible to 
work, it is considered that provided the experiments are carried out 
upon sound economic and scientific lines, the chances of success are 
considerably greater than they were in the past. 
The Point to which the Experiments have at present 
BEEN CARRIED. 
As has been stated elsewhere the experiments at present being carried 
out by the Forest Department as to the possibility of treating timber 
with an antiseptic in order to preserve it from decay or destruction by 
white-ants come under two heads. The first are laboratory experi¬ 
ments, carried out on a small scale, which consist in treating the various 
pieces of timbers with the better known antiseptic solutions, and then 
placing them in the ground and keeping them under observation. 
These experiments, together with those relating to absorption, cost, 
strength and durability have been in progress about eighteen months. 
Under the second head come the experiments carried out on a more 
extensive scale in the course of which a large number of sleepers are 
treated by a process, the value of which has been established by previous 
records and laboratory experiments, and handing over the sleepers after 
treatment to the Railway Authorities by whom they are placed on an 
open line and periodically inspected. So far arrangements have been 
made to Powellise 5,000 sleepers of Dipterocarpus tuber culatus , the 
“In” wood of Burma, Dipterocarpus alatus , Finns excelsa or Kail wood, 
Finns longifolia or Chir wood, and Terminalia iomentosa or Sain wood. 
It is hoped that these sleepers will be rendy to hand over to the Railway 
authorities by April 1911. 
Another scheme has been submitted by which it is proposed to treat 
2,500 sleepers of the same five species above mentioned by the Open Tank 
Method with Avenarius Gafbolineum oil and after treatment to place 
them in open lines so as to ascertain their behaviour under varying 
conditions of climate and mechanical strain.* 
(2) Proposals as to Future Experiments. 
While formulating proposals as to future experiments it is necessary 
to consider the three most important factors which govern the possibilities 
* Note.— Since writing this paragraph, this experiment has been successfully 
launched, and a third set of experiments is under consideration by which 1,500 
sleepers will be treated with Green Oil and Chloride of Zinc, by the mixed Impregna¬ 
tion Method. 
( 172 - ) 
