- Part I.] Puran Singh : Turpentine Oil and Indian Rosin. 83 
improvement in tlie oil repays the extra cost of using methylated 
spirit. 
CHAPTEE VII. 
General Directions for Turpentine Distillation. 
(1) It is essential for the production of good turpentine oil and 
rosin to “ cut ” the still when about 90 per cent, of the total 
calculated quantity of oil has passed over, in case the method of 
spirit or acetic acid distillation is adopted. If not, the still should 
be “ cut ” when 80—85 per cent, of the total calculated oil has 
distilled over. 
(2) When resin is distilled under high temperatures, a good deal 
of resinous matter is carried along mechanically with the distilling 
vapours, and is deposited in a solid form in the delivery pipes, and 
this slowly getting dissolved in the turpentine oil vitiates the quality 
of the latter. This can be avoided by carrying on the distillation 
slowly at low temperatures, and by fitting a dome-shaped lid to the 
still instead of the fiat one as in use at present at Bhowali. 
(3) To reduce the unpleasant pine and naphthic odour, the oil 
should be washed with lime water or with 2 per cent, carbonate of 
soda solution, in closed washing cylindrical cisterns fitted with stir¬ 
ring appliances, stop-cocks and gauge glasses-. 
(4) The oil should never be allowed to remain long exposed to 
the action of moisture and air. After it is washed it should be im¬ 
mediately filtered and sealed in clean new canisters. It is prefer¬ 
able to have some automatic arrangement for filling the canisters, air 
having been previously excluded. 
(5) The open-mouthed copper cylinders, that are at present being 
used for the collection of distilled turpentine, should give place to 
closed cylindrical vessels wdth gauge glasses, marked at definite 
points for the workman to j udge if the requisite quantity of turpen¬ 
tine oil has distilled over. On seeing the oil reach the mark he should 
remove the vessel. 
(6) Too much care can scarcely be exercised in distillation opera^ 
tions, in washing, in packing, and in seeing that the turpentine does 
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