446 



FOODS AND FOOD ADULTERANTS. 



whole stirred with a glass rod, the lower part being flattened parallel to vertical axis, 

 and stirring continued until the mercury ceased to rise. 



Of course the final temperature varied with initial temperature, but the idea was 

 to have samples of standard oils on hand and as the temperature varied in the room 

 from day to day to make comparisons at same temperature between oil under obser- 

 vation and standard oils. Variations also occur with rate of stirring, but it is re- 

 markable how close agreement is with practice. For example I cite 



Experiments made June 18, 1834, with standard oils. 



Experiments with mixtures of above oils. 



The calculated increase is based on the numbers 39 and 53 given in the first 

 table. It will bo observed that the differences reduced to percentages are large, :ind 

 that the initial temperature of the mixed oils are above those of the original oils, 

 yet there is no question about the detection of the mixture and the estimation of tho 

 proportions on a commercial scale. In point of fact what we demanded was pure lard 

 oil only to conform to a certain standard and the test as applied secured this. I have 

 better results than those cited, but this is probably as good as the average inspector 

 will get. 



It is said, however, that l>eeeli-nut-fed pork gives an oil that yields results liko 

 cottonseed. In a thorough study of the subject this should bo considered as well as 

 the effects of ago and of the dim-rent, methods of refining. 



(/) Crystallization point of fatty acids. The maximum triiiprrutim' 

 reached during the process of crystallization of the fatty acids is also a 



