424 FOODS AND FOOD ADULTERANTS. 



true that such attempts have never attained any importance from a 

 commercial point of view. 



(G) PROPERTIES OF ADULTERATED LARDS. 



Jii external appearances to an unskilled person adulterated lards are 

 not appreciably different from the pure article. An expert, however, 

 is generally able to tell, by taste, odor, touch, and grain, a mixed lard 

 from a pure one. There is usually enough lard in the adulterated arti- 

 cle to give to it the taste and odor of a genuine one. Mixtures of fat, 

 however, have been made, and perhaps sold as lard, which contained no 

 hog grease whatever.* In the following descriptions an endeavor has 

 been made to give the chief characteristics of an adulterated lard on 

 the same plan as the descriptions of pure lard and the adulterations 

 thereof which precede. 



A. PHYSICAL PROPERTIES. 



(a) Specific gravity. But little stress can be laid upon the numbers 

 representing the specific gravity of adulterated lards since the materials 

 of which they are composed have nearly the same specific gravity as 

 the pure article. The addition of cotton oil, however, raises the specific 

 gravity, and when this substance is present in quantities above 15 per 

 cent, its influence on the specific gravity of the sample is marked. At 

 35 the specific gravity of adulterated lards varies from .900 to .910, 

 compared with water at same temperature. 



(&) Melting point. The melting point of the adulterated lards is in 

 most cases nearly the same as that of pure lards, but in some samples 

 lower. This arises from the fact, which has already been noticed, of the 

 low melting point of the cotton oil, which is one of the principal adul- 

 terants used. The numbers representing the melting points of adul- 

 terated lards, which will be found in the following tables, emphasize the 

 fact which has already been noted that the lowering of the melting point 

 is not theoretically proportional to the content of cotton oil found in the 

 adulterated lards of commerce. In a number of samples of lards con- 

 taining cotton oil from Fairbauk & Co. the lowest melting point found 

 was 31.3, and the highest 41.9, and the mean 38.1. In the series of 

 samples from Armour & Co. the lowest melting point noticed was 38.9> 

 and the highest 43.3, and the mean 40.6. The melting point of the. 

 Armour samples approaches much nearer that of pure kettle rendered 

 lard than those received from Fairbauk vS: Co. the latter being nearly 

 the same as for steam lards. Although the melting point is not of 

 itself a'property of very great importance from an analytical point of 

 view, yet its determination should never be neglected in a comprehen- 

 sive analytical examination. 



(c) Color reaction. The amount of coloration .shown by an adulterated 



* Cotolciie is !i mixture of cotton oil :in<l oleo-stoarinr. jin-pnrrd l>y N. K. 

 & Co. It is sold under its trim njuiir juul not as lard. 



