Part I.] Furan Singh : T argentine Oil and Indian Rosin. 67 
Tlie optical rotation in a 100 mm. tnbe of the various fractions 
of samples A, B, C and D are given in the following table: — 
Present 
SAMPLES. 
Previous 
SAMPLES. 
C (crude). 
D (refined). 
A 
i b 
1 
165° C. or below . 
.. 
-9° 45' 
. i 
165° C. to 170° C. . 
-5° 25' 
-4° 40' 
—5° 15' 
7° 15' 
170° C. to 175° C. . 
+ 2° O' 
3° O' 
+ 2° O' 
+0° 20' 
175° C. to 180° C. . 
+ 8° 5' 
180° C. to 190° C. . 
•• 
•• 
J. +6° 35' 
+7° 5' 
190° C. to 195° C. . 
•• 
J N 
i i 
Residue 
•• 
+ 10° 45' 
r i 
+ 17° 25' 
From the above results it appears that the rectified oil D is 
considerably richer in low-boiling terpene than the crude oil C, but 
that it is much inferior in this respect to the rectified turpentine oil 
purchased in London, since 85 per cent, of the latter distilled below 
165° C. whilst none of the Indian oil did so. The rectified oil D 
is, however, superior to A and B, as 89 per cent, of it distilled below 
175° C. against only 80 and 84 per cent, respectively in the case of 
the latter samples. The crude oil C is intermediate between samples 
A and B, since 83 per cent, of it distilled below 175° C. 
Experiments were made to compare the behaviour of sample 33 
on exposure to air with that of the turpentine oil purchased in 
London, and it was found that the Indian oil evaporated more 
slowly, oxidised much more rapidly and gave • far more oxidised 
residue than the London oil. In these experiments, quantities 
of 10 c.c. of each oil were exposed in glass dishes 8 cm. wide, 
with vertical sides 3*6 cm. high. In six days the London oil had 
evaporated, leaving an immobile film of thick liquid, whilst the 
Indian oil left a layer of syrupy liquid, which became immobile 
two or three days later. After seven weeks the residue left by the 
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