52 COAL-TAR COLORS USED IN FOOD PRODUCTS. 



Methylene Green as poisonous as Methyl Violet. 



Nigrosin as poisonous as Methyl Violet. 



Eosin (Tetraiodo fluorescein) kills in 0.1 per cent solution, but lets live 24 hours in 

 0.01 per cent solution. ( Untersuchungen aus dem Botanischen Institut zu Tuebingen, 

 1886-88, vol. 2, pp. 179-331.) 



WINOGRADOW. 



Winogradow reports on the influence of certain coal-tar colors on 

 digestion, which experiments were carried out in glass. The con- 

 clusions arrived at are as follows : * 



The twelve colors, Safranin (584}, Azo Fuchsin G. (93), Coerulein S. (527), Jodeosin 

 (516), Magdala Red (614), Benzopurpurin (277, 278, 279, 307), Ponceau 2R (55), 

 Orange II (86), Phloxin RBN (?), Chrysanilin (532), Azoflavin (92), and Cerise 

 (mixture of 448 and 532), even in amounts of a few milligrams, which in relation to 

 the digestive fluid make up only a few tenths or hundred ths of a per cent, exercise a 

 strongly retarding, almost completely inhibitive, action upon the peptic digestion of 

 albumen. 



The thirteen colors, Chinolin Yellow (667), Acid Green (434, 435), Azo Acid Yellow 

 (92), Naphthol Yellow (4), Primulin (659), Anilin Orange (87), Metanil Yellow (95), 

 Methylene Green (651), lodin Green (459), Yellow T (84), Anilin Green (?) 

 Auramin O (425), and Martius Yellow (3), retard the digestive action noticeably, 

 although to a slighter degree than the first 12 colors; in any event they are not indif- 

 ferent. (Zts. Nahr. Genussm., 1903, v. 6, p. 589.) 



HEIDENHAIN. 



Heidenhain, in his book entitled "Ueber chemische Umsetzungen 

 zwischen Eiweisskorpern und Anilinf arben " (Bonn, Germany, 1902), 

 reports on the behavior of 70 different coal-tar colors, 3 intermediate 

 products, and 4 raw materials toward various albuminoids such as 

 serumalbumen, albumen, and casein. 



Of these 70 colors, 21 have been investigated physiologically, and 

 the results embodied in this report; and of these 21, 17 were on the 

 United States market as food colors and 4 were not on this market. 



Limiting the attention to the 17 that were offered, 4 of them are 

 among the 7 permitted colors of Food Inspection Decision 76. 



In the cases where albumen and casein were used, they were 

 employed in 0.5, 0.1, 0.02, 0.01, and 0.005 per cent solutions, acidified 

 with acetic acid; the coloring matter w T as employed in a 1 per cent 

 solution in the first strength, in 0.1 per cent solution in the second 

 and third strengths, and in a 0.02 per cent solution in the fourth and 

 fifth strengths, and one volume of coloring-matter solution was 

 brought in contact with five volumes of albuminoid solution. 



The following colors precipitated the albuminoid in all the strengths. 

 The numbers in parentheses indicate the Green Table numbers; 



i It is not always possible to identify the trade names given by Winogradow with specific numbers in 

 the Green Tables; the numbers in parentheses after the name indicate the number in the Green Tables 

 wherever that identification could be made with any reasonable certainty; wherever two or more numbers 

 appear, the context indicates that the name might apply to any one or all of them. 



