Indian Forest Records. 
[Vol. IV. 
86 
Rosin and Colophony. 
The -following specimens of colophony have been examined: — 
(a) Colophony of Finns longifolia from Naini Tal, United 
Provinces. 
(b) Colophony prepared in the Imperial Institute from the 
crude turpentine from Naini Tal, United Provinces. 
(c) Colophony prepared in the Imperial Institute from the 
crude turpentine of Finns excelsa from the Punjab. 
id) Colophony prepared at the Imperial Institute from the 
crude turpentine of Finns Gerardiana from the 
Punjab. 
The specimen of the colophony of Finns longifolia from the 
Punjab was very similar to (a) above, and was not examined. The 
results of the examination are given in the following table: — 
— 
(a) 
(6) 
(c) 
id) 
Melting point 
75°—78° C. 
Specific gravity 
1-067 
Ash, per cent.. 
0-125 
Saponification value * 
190-0 
193-0 
194-0 
176-0 
Acid value 
165-0 
170-1 
170-0 
174-0 
Unsaponifiable matter, per 
cent. 
5-0 
3-8 
9-0 
6-9 
Specific rotation (a) D . 
9° 40' 
Nil 
—4° 48' 
11° 20 
* Milligrams of potash per gram of colophony. 
For comparison with these results the following figures obtained 
for typical samples of the American and Bordeaux colophonies of 
commerce may be quoted : — 
— 
American. 
Bordeaux. 
Saponification value 
184-0 
184-0 
Acid value .... 
175-6 
175-0 
Unsaponifiable matter, per cent. . 
6-5 
Nil 
Specific rotation (a) D 
29° 5' 
Nil 
[ 86 ] 
