512 



FOODS AND FOOD ADULTERANTS. 



absorption of iodine by lard showing a very low absorbtive power. His 

 results are given in the following table: 



Mr. Grey will fix the average for English lards at 57 per cent, instead 

 of 62 as taken by Mr. Allen. Mr. Fox stated that he had recently 

 found 50 per cent, of pea-nut oil in lard oil, determining it by the altered 

 specific gravity and the presence of-arachidic acid. 



Mr. M. F. Horn* gives a method for the quantitative estimate of par- 

 am' ne, cerosin and mineral oils, in fats and wax. Inasmuch as these 

 adulterations are not likely to occnrin lard I will cite only the original 

 paper. 



Roland Williams t gives a table showing the iodine numbers and melt- 

 ing-points of certain fatty acids. The melting-points were determined 

 by the ordinary capillary-tube method. Following are his results : 



The low melting-point in the case of lards is explained by Mr. Wil- 

 liams on account of the fat having been taken from the entire animal. 

 As might be expected the fatty acids absorb a slightly greater percent- 

 age of iodine than the glycerides from which they were made. 



Prof. Stephen P. Sharplessf relies upon the usual tests for the detec- 

 tion of the adulteration of lard with cotton oil. Bechi's test, ho says, 

 gives good results. Nitric acid of 1.35 specific gravity gives only a faint 

 color with pure lard, white with lard adulterated with cotton oil it gives 

 a color more or less intense. For the detection of added stearine made 

 from tallow Dr. lielfield's microscopic test is employed. The suspected 



'Tim Analyst, ().-(, Irf-Jg, p. 181. 

 ' I'lir Analyst, .May, 1888, p. 88. 

 * The Analyst, April, 1888, p. 69. 



Zcitscbr. f. Anj^w. Clu-initv No. If,, 



p. 4f,'J. 



