COMPILED DATA UNDER GREEN TABLE NUMBERS. 57 



the nonpoisonous nature of these substances. This action is to be regarded as a purely 

 nuvhaniral one, a view which I will thoroughly confirm in my second communication. 

 With respect to the anilin colors not soluble in water, Ehrlich long before me, in his 

 excellent publication on the oxygen requirements of the organism, has arrived at this 

 view, and has excellently described it as merely a penetration of the organs. 



4. Lehmann (Meihoden der Praktischen Hygiene, Wiesbaden, 1890, 

 p. 543) says: 



The hygienic significance of coal-tar colors has heretofore been judged quite vari- 

 ously. When the intensely poisonous nature of the first impure and particularly 

 arsenic-containing coloring matters became known the inclination was to judge the 

 coal-tar coloring matters very strictly; when it was subsequently recognized that 

 the contaminations were largely the cause of the harmfulness to health, there followed 

 a period in which no poisonous coal-tar coloring matter was known in any pure con- 

 ditioii. (Eulenberg & Vohl, 1870.) More recent investigations, however, have 

 disclosed a series of coal-tar coloring matters which, as a matter of fact, possess a con- 

 siderable poisonous action, and already cases, although not numerous, have become 

 known in which serious and even fatal poisonings by means of pure coal-tar colors 

 have arisen. Alongside of this there still continue to exist the possibilities described 

 by Eulenberg and Vohl (Viertel-Jahressch. fiir Gerichtliche Mediz, 1870), whereby 

 harmless coloring matters become harmful; but the realization of these possi- 

 bilities has become essentially more seldom through improvements and changes in 

 manufacture. 



5. Stilling (Arch. Exper. Pafhol. PJiarmak., 1891, v. 28, p. 352}, in 

 speaking of the anilin colors as antiseptics, says: 



It is the nonpoisonous nature of these substances, their easy solubility and dif- 

 fusibility, and above all their inability to coagulate albumen which lends them their 

 importance, which now can be only difficultly denied. 



NOTE. The work of Heidenhain abstracted in Section VIII does 

 not fully bear out this article. 



6. Erdmann (Pharm. Centralh., 1892, v. 33, p. 357) says: 



The sulphonated as well as the carboxylated coal-tar dyes will not have any pro- 

 nounced action on the organism. Acid dyes may therefore be regarded in general 

 as nonpoisonous, whereas in the case of basic dyes a physiological examination is to be 

 recommended before they are permitted to be applied to articles in daily use or 

 indeed to be used in food or drink. 



NOTE. Out of the 80 different dyes on the food-color market in 

 the summer of 1907 whose composition was avowed, 15 were basic 

 and 65 were acid. 



7. Tschirch expressed himself as follows: 



1. The coal-tar colors, and in a narrower sense the anilin colors, are no longer 

 harmful on account of their arsenic content, since at the present time the great majority 

 of them are prepared free from arsenic. 



2. Some colors have shown themselves to be harmful to the system. 



3. Coal-tar colors, in general, should therefore be permitted for the coloring of foods, 

 but those that have been found to be harmful should be expressly and specifically 

 forbidden. 



