105 
Part II.] Pearson : Antiseptic Treatment of Timber. 
From the above figures it will be seen that, generally speaking, the 
cost of treatment is high when tar-oils and products therefrom are used, 
such as Creosote , Avenarius Carbolineum , Jodelite, and also for the 
Saccharine process, while the cost of impregnation with the various salts 
is not expensive; take, for instance, Chloride of zinc , Copper sulphate, 
and Bellit (Sodium-fluoride). On the other hand, the value of processes 
by which an oil is injected or applied is generally greater than is the case 
when timber is treated with a salt, for the reason that the oils are less 
volatile and are not so easily removed from the timber by the action of 
rain. The above points will be taken into consideration in choosing the 
antiseptic solutions with which further experiments are to be made. 
(3) ANTISEPTIC SOLUTION WITH WHICH IT IS PROPOSED 
TO EXPERIMENT IN FUTURE. 
(a) Impregnation by Pneumatic Injection. 
(1) Creosote. —Creosotmg by the old method is not practicable 
being too expensive. It is proposed to experiment with creosote by the 
Ruping process. As no Ruping plant exists in India, it will be necessary 
to send 50 or 100 sleepers of eac of the species mentioned in class I 
on page 11, Chapter I, to Europe for treatment. If the experiment is 
a success, further schemes for erecting a Ruping plant in India might be 
considered. 
(5) HasJcin process. —The process is a cheap one, but not altogether 
applicable to India, though it deserves consideration. The best chances 
of success are to fulfil to the utmost the conditions on which the whole 
theory of the process is based. To do this the timber to be treated must 
contain much sap or oleo-resinous substances, and when treated it should 
be in a green state. Such a species as Dipterocarpus tuberculatns is 
recommended. The timber will have to be sent to Europe for treatment 
in the shape of freshly cut logs, to be converted into sleepers on arrival. 
It will be necessary to send sufficient timber home to produce 100 B. G. 
sleepers. 
(5) Sulphate of copper. —It is not proposed to make any experiments 
with this salt at present. 
(4) Chloride of zinc. —This process will be dealt with under “Mixed 
Impregnation.-' 
( 178 ) 
