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



N 

 oxidised to 0, precipitated as CaO, &c., and titrated= 16'0c c-r-rKMnO^ 



whence percentage of glycerin = 8*45 

 3. 1"99 gin. oil saponified as above. Details exactly the same as in 

 the preceding. 



N 



250c. c. glycerin solution = 35c. c. — KMnO 



'4 



250c. c. glyc. sol. =37-5 — KMnO^ 



glycerin °/o=8-l 



4. 1*3165 gm. oil saponified according to the improved method. 



Details the same as in the previous cases — 



N 

 250c. c. glycerin sol. = 25-0 c. c. -rr- KMn04 



= 0'115 gm. glycerin 

 glycerin 7, =8-7. 



The permanganate solution on direct titration against ferrous am- 

 monium sulphate gave 



Ic. c. =5-6 (1-002) mgs.Fe. 



Whence glycerin per cent, (corrected) = 8*7 (1— 0'02) 

 =8-53 

 6, 2*0365 gm. oil saponified : details the same — 



N 



To 



Glycerin per cent. =8*33 (corrected). 



6. 1"264 gm. oil saponified as above 



N 

 250c. c. glycerin solution = 23-75 c.c— KMnO^ 



Whence glycerin per cent. = 864. 



It would thus be safe to take the percentage of glycerin in mustard 

 oil as 85. The oil used was not in every case identical, but from 

 different samples, in fact, the same as used in the determination of the 

 saponification equivalent. 



Detekmination op Glyceein in Mutton-fat by the Asbestos Method. 



1. 10425 gm. fat were saponified under pressure as in the case of 

 mustard oil. 



The glycerin solution was made up to 500 c. c. of which 100 c. c. were 

 oxidised to 0. The CaO was dissolved in dilute HgSO^^ and made up to 



N 

 250c. c. ; 50c. c. of the latter were equivalent to 1 c. c. — r KMnO^ 



or 250CaO sol. = 100c.c. glyc. sol.= 6c. c. ^ KMnO. 



r, J 10 * 



