1919.] The Purification of Indian Sesame (Til) Oil. 325: 
slanting glass tube E, held in position by means of a clamp. 
d oil was collected in the glass receiver G, and 
poured back into the funnel A. The oil was, on the average, 
run about twice a day. e samples were taken after suitable 
intervals and compared with the control sample. It was found 
that, in dripping from the dropping funnel, the drops fre- 
quently assumed the form of spheres which rolled down the 
slanting tube and shot beyond the end on to the walls of the 
covering glass. This was prevented by the insertion of the 
plug of cotton-wool (a) 
Exposure to both air and sunlight gave a progressive 
improvement in colour 
In the first sam le of oil, after nineteen days’ treatment, 
the oil was Becueall2 white and the smell, though not absent, 
was not unplea 
In the at sample, treatment in the same way showed 
moderate improvement in colour after fourteen days. The 
smell was still unpleasantly apparent, though a marked im- 
provement on the original sample, After 21 days’ treatment 
marked improvement in colour over the sample treated for 
twenty-one days 
After twelve weeks’ treatment wea sample resembled pure 
glycerine both in colour and consistency. It was practically 
colourless. The odour, however, still remained unchanged. 
Errect oF SutpHurRiIc AcIpD. 
Til Oil’ was treated with a varying amount of strong 
the acidic water. This process of washing was repeated several 
times till the oil was free from aci 
A series of 21 experiments was ‘conducted in four wa 
The first set comprised three experiments 100 c.c. of the 
oil was treated with 1 ¢.c., 2 c.c., and 3 c.c. of vesal sul- 
huric acid respectively and the period of acid contact before 
washing with water was 19 hours. The sample number 1, 
ie. treated with 1 c.c. of acid, showed improvement in colour 
which was practically of the same degree as in sample No. 9. 
Samples Nos. 2 and 3 were darker. 
In the second set comprising six experiments 100 c.c. of 
the oil was treated with 1 c.c. of acid and the period of acid- 
contact varied from 5 to 30 minutes with an interval of 5 
minutes each. Samples Nos. 4 to 8 showed no improvement 
in colour but in sample No. 9 the sage was improved to the 
same degree as in No. | of the first se 
