856 



FOODS AND FOOD ADULTERANTS. 



For the average acid number (8=20) for example the sapouification number (a 

 and the total acid number (} have the following values : 



s) 



If the proportions are not taken from the ether and acid numbers (v. Hiibl), but 

 from the acid and total acid numbers, a value is obtained for v. Iliibl's normal wax, 

 and the sapouification number 95, of S s : a = 72.77 : 20 = 3.64. 



Still these proportions are not as constant for pure wax as v. Hiibl assumes. Accord- 

 ing to our own results a wax of 18 acid number and 90 saponificatiou number can not 

 be pronounced adulterated. A large number of samples of yellow wax of different 

 origins gave values between 88 and 93 for the total acid number. 



Determination of ceresin and paraffin in wax. Calculating the wax content of a 

 ceresin mixture from the total acid number S according to the formula 



W 



1005 



92.8 



(3) 



in which 92.8 represents the average total acid number (corresponding to the sapoui- 

 fication number 95) a small error is encountered from the fact that the wax has laken 

 np 2.33 parts of water in saponifying. Therefore it is more exact to calculate, 



WOioS 



92.72 



whence 



92.75 S ( 1 w) 92.75 0.02285 



W= 100: 102.33 == .9772. 



(4) 



However, as the error at most amounts to only .7 per cent, it may be neglected, 

 especially when the saponification number of the wax contained in the mixture is 

 unknown. 



The results of four mixtures made from ceresiu and wax are given below in tabu- 

 lar form : 



