188 



COAL-TAR COLORS USED IN FOOD PRODUCTS. 



useless; the amount of material on hand was unfortunately so small 

 at the beginning (2 ounces or less, in most instances) that the utmost 

 economy of material was necessary to get the data reported, on 

 account of the large amount of material needed in the exploratory- 

 work done in trying out the methods for determining arsenic, heavy 

 metals, and ether extractives. 



In the arsenic test the coloring matter, as a whole, was considered, 

 and no attempt was made to get at the actual amount of real coloring 

 matter in the exact weights of the material as a whole, used for such 

 examination, and consequently the results are not translatable into 

 actual weights of real color used. It is obvious that if 2 grams, or 

 other weight of the substance as a whole, failed to pass any test when 

 the whole amount was considered as though it were all color, the 

 material could not possibly have passed those tests if amounts thereof, 

 corresponding to the prescribed weights of actual color used, were 

 taken; also it is clear that if the sample, as a whole, passed a given 

 test, at a given weight thereof, it would not necessarily have passed 

 that test had an amount thereof, corresponding to that same weight 

 of actual color, been used. 



The amount of actual or real coloring matter in 27 of these 30 

 specimens is not greater than shown in the following: 



Per cent of actual coloring matter in 27 samples. 



In order to make these analytical results comparable among them- 

 selves and with other analytical results later to be given, the items 

 common salt, volatile and nonvolatile insolubles, total, insolubles, 

 acetate ether extract, acid ether extract, and total ether extract of 

 the preceding tabulations have been recalculated in parts per iOO 

 of actual or real coloring matter as just enumerated: 



