IMPROVED METHODS FOR FAT ANALYSIS. 103 



In other words, assuming a fat to be composed of a mixture of triglyc- 

 erides and free fatty acids, if the group C3H2 in an amount proportional 

 to the glycerol content be deducted from 1.00, the percentage of total 

 fatty acids may be obtained. 



(RCOO)3C3H6+RCOOH -C3H2 =4 RCOOH 

 Neutral fat Free Total 



fatty fatty 



acids acids 



T=1.00-t51?G or 



1.00 -.00022585 6 (2) 



In case of fats containing appreciable amounts of unsaponifiable matter 

 proper correction should be made for the same. 



Neutralization Number and Mean Molecular Weight of Total Fatty 

 Acids. — The neutralization number (n) and mean molecular weight (m) 

 of the total fatty acids (T) can be calculated fronji the ether (e) and saponi- 

 fication (s) numbers by means of the formulas — 



(3) 

 (4) 



1.00 -.00022585 e 

 56108 



Neutralization Number and Mean Molecular Weight of Fatty Acids in 

 Neutral Fat. — The molecular weight (mi) and neutralization number 

 (ui) of the acids in the neutral fat can be calculated from the ether num- 

 ber (e) and the percentage of neutral fat (N) — determined either gravi- 

 metrically or by difference ^ — by the formulas ^ — 



Molecular weight of neutral fat = x N or 



e 



168324 N 



' The unsaponifiable matter is a source of error unless deducted. 

 'Wright, Analysis of Oils, etc., p. 130 (1903). 



