490 FOODS AND FOOD ADULTERANTS. 



NOTES ON TABLK 21. 



The samples analyzed show that the compound lards manufactured by 

 Armour & Co., of Chicago, have nearly a uniform constitution. The spe- 

 cific gravities of the various samples differ only slightly from the mean. 

 The maximum difference is in No. 5572, viz, .0015, and the maximum 

 + difference in No. 5G11, viz, .0008. The melting points are also re 

 markably constant, the two maximum variations of a positive and neg- 

 ative sign being + 2.7, in No. 5557 and 1.7 in Nos. 5564 aud 5595. 

 The same agreement is also noticed in the melting and crystallizing 

 points of the fat acids. The refractive index in most cases is only 

 slightly above that of pure lard, showing only a small addition of cot- 

 tou oil, or a correction of the index thereof by a correspoudiug addition 

 of a stearine with low index. 



The rise of temperature with sulphuric acid shows only notable 

 variations in Nos. 5561 and 5584. 



In the latter of these the iodine number is correspondingly increased, 

 but not so in the former. This is only another of the numerous illus- 

 trations of the analytical perplexities encountered in the study of mixed 

 glycerides. 



The reactions with silver nitrate reveal very well, in almost every 

 instance, the presence of cotton oil, but in some cases the phenomena of 

 reduction of silver are not sufficiently developed to distinguish the 

 samples from lard containing enough of impurity other than cotton oil to 

 give a color with silver nitrate. The silver test applied to the free 

 acids did not afford satisfactory results ; a fact which has already been 

 noted, and its possible explanation given. 



In the iodine numbers, those obtained for Nos. 5552, 5584, aud 5595 

 are much above the mean, while in one case, No. 5572, the percentage 

 of iodine absorbed, viz, of 54.11, would indicate the admixture of a 

 larger quantity than usual of oleo-stearine. 



Fairbanks lard. 

 No. 

 5558. Prime refined family lard, purchased in Mobile, Ala. Affidavit of F. H. Mc- 



Larney. 

 5561. Prime refined family lard, purchased in Macou, Ga. Affidavit of T. Skelton 



Jones. 

 5563. Choice refined family lard, purchased in Savannah Ga. Affidavit of Isaac G. 



Haas. 

 5567. Prime refined family lard, purchased in Dallas, Tex. Affidavit of Thomas F. 



McEunis. 

 55(59. Prime refined family lard, purchased in Saint Louis, Mo. 



5573. Prime refined family lard, purchased in Saint Louis, Mo. 



5574. Prime refined family lard, purchased in Atlanta, Ga. 



5576. Prime refined family lard, purchased in New Orleans, La. Affidavit of E. K. 

 Converse. 



5586. Prime refined leaf-lard, purchased in Norfolk, Va. Affidavit of W. B. Pear- 

 man. 



