COMPILED DATA UNDER GREEN TABLE NUMBERS. 73 



We may expect that more detailed investigations in this respect will be made at the 

 >per time by pharmacologists, since study of the mechanism and chemistry of the 

 [action of the poisonous substances on the animal organism is their province; for the 

 ivgienist it is quite sufficient merely to establish the fact that a given substance is 

 >nous or harmful, and he need not go any further. For this reason, in those cases 

 which I desired to clear up the causes of death of the animals in my experiments, 

 land to record pathological and anatomical changes (although by the terms of the regu- 

 lations governing this competition, a close study of the action of the dyes, and the 

 (ascertainment of the mechanism and chemistry of their action was not required), I 



Lied in a person more competent than myself on these questions. 



Not counting the duplicates we made five autopsies all told. In all these cases death 

 resulted from paralysis of the heart. The pathological and anatomical changes in all 

 leases, except one, did not present anything specific, and finally reduced themselves to 

 a feebly expressed turbid swelling of the heart and of the liver, a rush of blood to the 

 {stomach, and a congestion of the internal organs. 



The exception was the autopsy of a dog, which died from Methyl Orange; this dog 

 died with the symptoms of paralysis of a cerebro-spinal nature. This experiment was 

 made twice, and the autopsies of both animals showed hyperaemia in the lowest part 

 of the spinal column, on the border of the anterior and the lateral columns. 



As to the symptoms of poisoning not resulting in acute death, here most frequently 

 was observed vomiting, diarrhea, and albumen in the urine, showing disturbance of 

 the functions of the digestive tract, and an affection of the kidneys. 



A highly typical picture of poisoning is presented by the sulphid Vidal dyes. They 

 cause rapid, almost instantaneous, deafening of the animal, whereupon the animal falls 

 on one side in convulsions and lies, not moving its body, but convulsively and rapidly 

 twitching its anterior limbs during several minutes. The tongue hangs out of the 

 mouth, a strong secretion of saliva is noted, then vomiting begins, and the dog gradu- 

 ally begins to revive; with difficulty he arises on his front feet and sits down, not being 

 able yet to stand on his posterior extremity, which is in a state of paresis. After a few 

 hours the dog becomes normal. The symptoms of poisoning, just described, are exceed- 

 ingly similar to the supposed " apoplectic form" of poisoning by hydrogen sulphid, 

 which had been studied on animals by K. Lehmann, and which was observed in per- 

 sons who inhaled air containing a few per cent of this gas. Air containing 0.1 to 0.3 

 per cent of hydrogen sulphid kills cats and dogs in 10 minutes. 



In our experiments in which were introduced substances containing sodium sulphid, 

 the poisoning must have been caused by hydrogen sulphid which was liberated from 

 the dye by the acid of the gastric juice, and which could cause poisoning also through 

 the stomach and through the respiratory apparatus. 



Fortunately Vidal dyes, owing to their repulsive odor, will scarcely find a wide 

 application in coloring food and beverages. 



SOME REFLECTIONS REGARDING FURTHER INVESTIGATIONS OF DYES FROM A SANITARY 



STANDPOINT. 



The present investigation, as well as all the investigations of the action of dyes on 

 animals by previous investigators, had for its object the solution of the question in 

 what number there exists among the dyes of the aromatic series dyes which possess 

 poisonous, or more or less pronounced harmful properties (answering essentially the 

 sanitary toxicological question). From the practical point of view such investigations 

 presented and do present the most important interest, inasmuch as they afford a possi- 

 bility of protecting the public from the use of obviously poisonous and harmful sub- 

 stances, but by such investigations questions of exceedingly sanitary importance are 

 not answered, namely: 



1. Ought we to consider as quite harmless those dyes which do not induce pro- 

 nounced symptoms of poisoning and which are designated herein by the term non- 

 poisonous? 



