Part t.j Pusan Singh : Turpentine Oil and Indian Rosin. 77 
remarked here that the consistency and colour of the crude oleo- 
resin varies with the season of the year and the temperature at 
the time of its exudation. The spring and summer collections 
give rosin of higher and light coloured grades and again the col¬ 
lections from the “ Virgin Dips ” {i.e., from trees tapped for the 
first time) yield the so-called “ Window Glass ” and “ Water 
White 55 grades of rosin and those from “ Yellow Dip ” {i.e., resin 
obtained from trees tapped in successive years) give dark-coloured 
varieties. 
The American works classify rosin into the following grades 
according to colour, varying from almost colourless to the darkest 
opaque:— 
W. W. Water white. 
W. G. Window glass. 
N. Extra pale. 
M. Pale. 
K. Low pale. 
J. Good No. 1. 
H. No. 1. 
G. Low No. 1. 
E. Good No. 2. 
E. No. 2. 
D. Good strained. 
C. Strained. 
B. Common strained. 7 T 
A. Black. J Low « rades - 
Besides the great care that is taken in the collection and classi¬ 
fication of crude resin, the colour and quality of rosin is influenced 
by the method of distillation depending chiefly on the temperature 
employed. The crude resin is melted either over an open fire or 
by a means of closed steam coils, and filtered before distillation. 
A fter distilling off the turpentine oil the molten colophony is drawn 
off from the still; it is then moulded, and barrelled. Before finally 
moulding it, it is customary to heat it over an open fire for some 
time to drive off the last traces of oil from it. This operation 
reduces its stickiness. Sometimes darker varieties of rosin are 
boiled by soap-makers with salt water to reduce their colour. In 
the factory, the finer grades are exposed to sunlight to make the 
tf Water White ” and “ Window Glass ” varieties of rosin. Rosin 
obtained from the spring resin or “ Virgin Dip” is ladled into shallow 
[ 77 ] 
^ Best. 
High grades. 
Ordinary colohpony. 
