Part IV.] R. S. Pearson: Antiseptic Treatment of Timber. 119 
short chimney at the other. It may be found convenient to erect a 
tripod over the tank, to which should be attached a set of pullies to facili¬ 
tate the loading and unloading of the timber. On the tank being charged, 
the antiseptic solution should be heated to between 80°C. and 90°€. and 
then allowed to cool down. The time, during which the timber is allowed 
to remain in the solution, will depend on the amount of antiseptic it is 
proposed to introduce into the timber, the nature of the timber and the 
size of the pieces to be treated. It is not improbable that some of the 
timber to be treated will be found to be too long to go into the tank, 
such as beams and possibly some of the posts; for, to build a tank of 
sufficient size to take such timber would not be justified owing to the 
limited number of such pieces to be treated. Such timber can, however, 
be given a considerable amount of protection by placing it over the 
tank and ladling the hot solution over it for 10 or 15 minutes and by 
repeating this operation at least twice. 
It has been mentioned that the position in which the timber is to be 
placed would affect the method of treatment to be adopted. In the 
case of timber which is destined for indoor work, the amount of protec¬ 
tion which it is necessary to give is less than in cases when it will be ex¬ 
posed to atmospheric influences. Thus, in the case of Pine rafters for 
roofing, 2 lbs. or 3 lbs. per cubic foot might be sufficient, while 5 to 6 lbs. 
per cubic foot of the antiseptic would be necessary to effectively protect 
verandah posts. Wood coming in contact with the ground, on the other 
hand, should be treated to refusal in Open Tanks. 
The choice of antiseptic, with which to treat timber destined for 
constructional work in dwelling houses, is a somewhat difficult problem. 
Creosotes, as used for sleeper work, cannot be used for internal work, 
as their odour is offensive', another reason being that creosoted wood 
cannot be painted. Good results have been obtained with Solignum. 
When first applied, it smells of creosote but this soon passes off. Arsenic 
solutions, such as Atlas, have been extensively used, especially in Assam, 
and the results obtained with this antiseptic are claimed to be quite 
satisfactory, the only objection to it being the poisonous nature of the 
solution. A very useful salt, with which to treat timber destined for 
internal construction, is Chloride of Zinc, used in a 2 per cent, solution ; 
it is cheap, colourless and odourless and provided the timber is well 
saturated, affords considerable protection. The timber, after treatment, 
on being thoroughly dried, should be painted with any suitable pigment 
mixed with oil. The above remarks are based on the assumption that 
the timber is destined for internal work in dwelling houses ; in the case of 
store-houses, barns, wooden bridges, canal weirs and structures of a similar 
nature, creosote alone or mixed with Petroleum oils is advocated, as the 
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