LARD AND LARD ADULTERATIONS. 

 The specific gravity of the mixture is therefore 



Cotton oil, 1.5 parts = .913x1. 5 = 1.3695 

 Stearine, 1. part = . 903 X 1. = . 9030 



471 



Mixture, 2. 5 parts = 

 Theoretical specific gravity =. . 909. 



2. 2725 



The following table, therefore, will give the approximate percentage 

 of adulterations corresponding to the specific gravities noted : 



Table showing approximate percentage of adulteration corresponding to different specific 

 gravities when the adulterants are cotton oil and stearine in respective proportions of 1.5 

 .*!. 



A general expression for the calculations above when applied to other 

 standards of temperature and actual results obtained may be easily 

 devised. The general formula however will still rest on the assumption 

 that the cotton oil and steariue are mixed in the proportions noted, and 

 this will Le found to be practically the case. 



Let s=the observed specific gravity at t. 

 .=specific gravity of pure lard at t. 

 6=specific gravity of pure cotton oil at t. 

 c= specific gravity of pure stearine at t. 



-=specific gravity of the mixed adulterants at t. 



2.5 



#=per cent, of adulteration. 



1.5&+C fl 

 ~^5~ 



For illustration we may apply this formula to the data collected in 

 tables which follow. Each analyst should carefully determine for him- 

 self, in a great number of samples, the true specific gravities of various 



