116 EXPERIMENT STATION. [Jan. 



The saj^onification nimiber of our sample agreed closely with 

 the average. The acid number indicates a slight acidity, but 

 this cannot be considered abnormal in an oil with such a high 

 percentage of unsaturated acids if exposed to light and air for 

 any length of time. 



Where there is no appreciable amount of unsaponifiable mat- 

 ter, monoglycerides or diglycerides, additional data can be 

 accurately calculated by formulae^ from the numbers just given. 

 Of these, the Zulkowski formula for total fatty acids (T) from 

 the ether number (e) is one of the most important. 



T = 1 — . 0002257 e or 95 . 70 per cent. 



If the saponification number of the fat (191.95) be divided 

 by the per cent, of total fatty acids (95.70), the neutralization 

 number (n) of the fatty acids is obtained (200.57), from 

 which the mean molecular weight (m) can be determined as 



'''''^^- 56158 ,^^ ^^ 



m= or 279.99 



n 



Glycerol (G) can be calculated in a similar manner to the 

 total fatty acids. 



G= .0005465 e or 10.42 per cent. 



The acid nund^er (a) can be converted into percentage of 

 acidity (A), expressed as oleic or the acid of any other molec- 

 ular weight. 



^ . 282.272 a __ ^ i • -^ 



A = — ^777^7^ — or . 03 per cent, as oleic acid. 

 5d158 



Employing the mean molecular weight (279.99) obtained above, 

 the acidity would be the same. N^eutral fat and unsaponifiable 

 matter can be determined by difference, 100 less the percentage 

 of acidity (.63), or 99.37 per cent. 



The per cent, of acidity (A) can also be calculated from the 

 acid number (a) and the neutralization number of the free 

 fatty acids, or in case that has not been determined, from the 



1 The derivation of these formula! avIU be given in another article. 



