64 P. 0. Ray — Chemical Examination of [No. 1, 



Saponification Equivalent for Niger-Seed Oil. 

 Guizotia ahyssinica (Nat. ord. — Compositse). 

 As this oil is one of the commonest adulterants of mustard oil, 

 a genuine sample of it was procured for experiments. 



1. 1.4605 gm. oil were weighed out into a flask, 20 c. c. of alcoholic 



potash were then added, the mixture covered with a watch-glass and 



treated to gentle boiling, with occasional agitation for 15 minutes. 



N 

 20 c. c. KOH = 15.95 c. c. -^ HCl (Blank experiment) 



Excess of alkali =6*1 „ „ 



Q .... . , , 9-85 X 0-0 2 805x10^ ,qq„ 



Saponmcation equivalent= t-txttp = 189"2 



1'4605 



2. 1*906 gra. oil were saponified as above with 40 c. c. alcoholic 

 potash. 



40 c. c. KOH = 31.9 c. c. ^ HCl 



Excess of alkali = 18*8 „ ,, 

 ... . 1 . 13-1 X 0-02805 X lOS ,.^^ 

 Saponification equivalent = T^oofi ~ iv^'o 



3. 2" 184 gm. oil were treated as above with 40 c. c. alcoholic potash 



solution. 



N 

 40 c. c. KOH =31-8 c. c. — HCl (Blank experiment) 



Excess of alkali = 17-0 ,, ,, 



. , . 14-8 X 0-02805 xlOS 

 Saponification equivalent = 9y\»l =-iyu-U 



The determinations described above were made in November 1891, 

 when the oil was fresh. It was preserved in a stoppered bottle and a 

 year after (November 1892) the saponification equivalent was found to 

 be 191-6. 



The saponification number for niger-seed oil may be taken as 190. 



Saponification equivalent for Cocoanut Oil. 



The sample was obtained from Viper Island, Port Blair, and was 

 guaranteed to be a " standard sample." 



1. 1'275 gm. oil were treated with 20 c. c. alcoholic solution and 



heated to boiling on the water-bath as in the previous cases. 



N 

 20 c. c. KOH =30-45 c.c. -^ HCl (Blank experiment) 



Excess of alkali = 18"76 „ „ 



. . . 1 . 11-7 xO-02805x 103 „_ , 

 Saponification equivalent = — JIoTS = i:o7 -4 



