326 Journal of the Asiatic Society of Bengal. {[N.S., XV, 
The third set comprised six experiments. 100 ¢.c. of the 
oil was treated with 2 c.c of acid and the period of acid-con- 
tact varied in regular intervals from 5 to 30 minutes. 
Samples Nos. 10 to 13 showed slight improvement in 
colour while in samples Nos 14 to 15, there was slightly in- 
creased improvement 
n the fourth set, comprising six experiments, 50 c.c. of 
the oil was treated with 1°5 c.c. of the acid and the period of 
contact varied in regular intervals from 5 to 30 minutes. No 
change in colour was observable in any of the samples. 
The control sample appeared slightly greenish. In all the 
As regards odour, it practically disappeared in all the 
samples. On warming the treated samples the odour comes 
back and resembles that of. the control sample. On cooling, 
however, the odour again disappears. 
Errect or Caustic Sopa. 
amounts of caustic soda and for varying periods of alkali- 
a 
ease. The alkaline water was syphoned off. The process of 
washing the oil with water was repeated several times till the 
A series of 34 experiments was conducted in five sets. 
The strength of the caustic soda solution used was 94:8 grms. 
per litre. 100 c.c. of the oil was taken for each experiment. 
tically entirely removed. In every case the colour was much 
improved. So far as colour and odour were concerned. there 
In the fourth set comprising six experiments the oil was 
treated with 1 c.c. of the alkali solution {i.e. containing 0°0943 
