REASONS FOR SELECTING SEVEN PERMITTED COLORS. 167 



BLUE. 



92. Indigo Carmine (Indigo disulpho acid) (3). 



Considering now the reds, and particularly 107, which, as the num- 

 ber appearing in parentheses after the scientific name indicates, was 

 wanted by 7 sources out of the 12 drawn on, this being the most 

 desired of all the reds, it would seem reasonable to believe that all the 

 wants supplied by 65, 103, 105, 169, 240, and 462 would be covered 

 by 107. Chemically 107 is closely allied to 65, 103, 105, and tinc- 

 torially it is likewise closely allied to 169, 240, and 462. 



Nos. 512, 517, and 520 are chemically quite different from the other 

 members of this group, and tinctorially they differ, being of a particu- 

 larly brilliant shade, and tinctorially more powerful; 517 being 

 desired by 5 out of the 12 sources drawn upon, and thus being the 

 most desired of these three colors, was selected in the expectation 

 that any work 512 and 520 could do in food products would be equally 

 well done by 517. For reds, therefore, the choice fell upon 107 and 

 517. 



Orange. Only one color was wanted, and that by 2 out of the 12 

 sources, and this was placed in the permitted list. 



Yellows. The choice of No. 4, which was wanted by 10 out of the 

 12 sources, was made in the expectation that every purpose that 89 

 could serve in food products could be served also by 4. 



Greens. Tinctorially and chemically the two greens are very 

 closely allied, and in view of the reasonableness of the expectation 

 that 435 could do all the work of 433 as well, its choice was regarded 

 as justified, especially as 435 was wanted by 4 out of the 12 sources, 

 as against only one for 433. 



Blue. No. 692 being regarded as harmless by all, and being the 

 only blue in the list, it was selected. 



In this manner six out of the seven permitted colors were selected. 



REASONS FOR ADDING PONCEAU 3R. 



An examination of the table on page 20 discloses the fact that 

 among the reds desired four were azo-reds made from anilin deriva- 

 tives as the first component, namely: 



53. Xylidin-azo-alphanaphtholdisulpho acid. 



54. Xylidin-azo-Schaeffer acid. 



55. Xylidin-azo-R-salt. 



56. Cumidin azo-R-salt. 



Each of these was wanted by 1 source out of the possible 12. This 

 was construed as an expression of a real need in the art of food coloring 

 for a color of this class. The reason for such a need was not then, nor 

 is it now, apparent, but the propriety of giving even a seeming need 

 due consideration was regarded as justified. For only one of the four 

 desired, namely, 55, could any specific references in the literature be 



