INFECTIONS OF THE DIGESTIVE TRACT 253 



that when indol poisoning is preceded by the adminis- 

 tration of physiological quantities of potassium cyanide 

 the indol poisoning takes a wholly different course from 

 that observed when indol alone is injected. As it is 

 known that potassium cyanide depresses the ability of 

 the cells to take up oxygen, it is reasonable to attribute 

 to this depression in the oxidizing capacity of the body 

 cells the failure of the organism normally to oxidize the 

 injected indol. It is not unreasonable to suppose that in 

 chronic disease in which the cells most concerned in 

 oxidation, such as the liver cells, have been structurally 

 damaged, that the ability to transform indol is less than 

 in a state of health. Such alterations are common in 

 human beings as a result of infections, alcoholism, and 

 intoxications, etc., and the experiments just quoted 

 enable us to understand how under such pathological 

 conditions the absorption of a moderate quantity of 

 indol from the intestine may be more harmful to the 

 central nervous system than is the case in persons whose 

 cells have suffered little deterioration as the result of 

 disease. 



As to the effects of absorbed indol upon the organism 

 in disease it is necessary to speak with caution, since there 

 is no evidence that indol is the only toxic substance 

 absorbed in those cases where it enters the organism 

 from the gut. Some light is thrown on the question by 

 experiments made through administering indol to normal 

 men by the mouth. In one of the cases, a robust young 

 man whose urine had been free from indican, felt no effect 

 from large doses given until after several days' adminis- 



