28 
Indian Forest Records. 
rVoL. VI 
It consists of a solvent extractor, and a steam-still, both fitted with 
Condensers; two settling tanks, a solvent storage tank, turpentine 
solvent and resin receivers and a tank for collecting the “ sludge.” A 
small distillation plant is required to deal with the 4 4 sludge ” which 
fs not shown in the drawing. 
The solvent extractor consists of a steam jacketted still, with a 
removable still-head, fitted with a double jacketted condenser, a worm 
condenser coil, safety valve and delivery pipe, leading to the main 
condenser. A removable perforated, tin-lined copper basket is supported 
on brackets in the still, and in this basket is fitted a spiral, perforated, 
steam coil, with a removable connection joint to the superheated steam 
in-let. 
Below the solvent still are two large settling tanks with leads to the 
steam-still and 44 sludge-tank.” 
The Steam-still is an ordinary turpentine still, fitted with a removable 
still-head and steam jacket and with a perforated steam spiral coil at 
the bottom. 
Both the solvent extractor and steam-still are provided with pres¬ 
sure gauges and thermometers ; while a pump, not shown in the drawing, 
is necessary to raise the solvent collected from the Steam-still to the Sol- 
vent-Storage-tank and a small redistillation plant connected to the 
44 sludge-tank.” 
2. Method op Extraction. 
Two methods of extraction are suggested, i.e. f either to use the- 
solvent first and the steam afterwards, or to use superheated steam first 
and the solvent afterwards. In either case the same plant will be re¬ 
quired, with this modification that in the former case the plant is as 
shown in the drawing, and in the latter the turpentine condenser will 
be above and the solvent condenser and storage tank will be on the. 
ground. 
J^i) Solvent extraction followed by steam distillation. 
By this process, the gum-oleo-resin is first treated with a solvent 
which, in this case, should be trichloroethylene as it is easier to be 
driven out of the oleo-resin than petroleum benzine. The oleo-resin 
is dissolved out by the solvent, leaving the gum with woody impurities 
as residue in the extractor. The solution of oleo-resin is run into 
the settling tank, to free it of fine particles of dust and dirt, and on 
settling is decanted and run into the resin still for distillation at tempera^ 
tures not exceeding 120°C.-130°C. The solvent is distilled off by gradu¬ 
ally raising the temperature of the still with the help of the steam jacket*. 
[ 330 ] 
