46 
Indian Forest Records. 
[Yol. VI 
The plant used to treat the Pine and Terminalia tomentosa sleepers 
was the same as that used for treating the timber with Avenarius Carboli- 
neum, while the Dipterocarp sleepers were treated in the ryinmana 
plant, details of which are given on page 37. 
(ii) Method of treatment with Chloride of Zinc and Green oil. 
( a) Treatment of Pinus longifolia and P. excelsa broad gauge sleepers . 
The Pine sleepers with which this experiment was carried out were 
all well-seasoned, having been prepared in the hills a full year before 
treatment. After conversion they were floated down the Tons River to 
Dhakpathar Depot, from there brought down the canal to Jagadhri and 
allowed to season for a further period of 2 or 3 months in the Depot. 
The method of treatment consisted in soaking the sleepers in a % 
per cent, solution of Chloride of Zinc, heated to a little over 50°C. for 2 
hours, and then allowing them to remain in the solution while it cooled 
down for a further period of 10 hours. After having allowed the sleepers- 
to dry thoroughly for 10 to 14 days, they were plunged into a hot bath 
of Green oil for 3 to 5 minutes and then removed. 
To ascertain the correct period of immersion necessary to make the 
sleepers take up 15 lbs. of the Chloride of Zinc solution, 10 per cent, of the 
sleepers were given varying periods of immersion, and weighed before 
and after treatment. Table XIII demonstrates the results obtained :— 
TABLE XIII. 
Species. 
Average absorp¬ 
tion per sleeper, 
of 6 sleepers, 
in lbs. 
Temperature of 
the Chloride of 
Zinc solution, i 
Period of immersion. 
Pinus longifolia 
lbs. 
5-5 
55°C. 
Half hour. 
Ditto 
9-8 
55°C. 
2£ hours. 
Ditto 
8-5 
60°C. 
3 
Ditto 
10-8 
71 e C. 
3 
2 hours heating and 10 hours 
Ditto 
12-3 
67°C 
Ditto 
200 
70°C. 
to cool down. 
Ditto 
Average 16-1 
lbs. absorption after 12 hours immersion. 
Pinus excelsa 
lbs. 
8 
85°C. dropping 
Heated for 6 hours and 
Ditto 
20-1 
to 56°C. 
70°C. 
allowed to cool for G 
hours. 
Ditto 
Ditto 
13-5 
70°C. 
Ditto 
Average 13-9 lbs. after 12 hours immersion. 
[ 176 ] 
