272 INFECTIONS OF THE DIGESTIVE TRACT 



its complete pairing. Under such .conditions it might 

 conceivably be a factor in the production of symptoms. 

 As compared, however, with the quantity of indol 

 existing as such in the organism, it seems to me that the 

 indoxyl must be insignificant. Evidence has already 

 been offered to show that while indol is not a highly 

 toxic substance for normal carnivorous or omnivorous ani- 

 mals, it becomes much more toxic when conditions arise 

 under which there is defective oxidation. This aspect of 

 the question of the toxicity of indol is one which has not 

 been touched upon by any writers upon this subject. 



Indigouria. It has long been known that there 

 occasionally occur cases of extreme indicanuria in which 

 the urine upon standing in contact with the air gradually 

 becomes blue and may liberate a pelicle of indigo upon 

 the surface of the urine at the same time that a precipi- 

 tate of fine particles of indigo occurs in the urine. Such 

 cases are, I believe, very exceptional and do not arise 

 except where the indicanuria has been of long standing. 

 The subjects of this indigouria are almost invariably 

 badly nourished and in poor, often precarious, health. 



Procher and Hervieux 1 have lately studied experi- 

 mental indigouria, which they found to arise when larger 

 quantities than one or two grams of indol are administered 

 by the stomach to dogs. The phenomena as they appear 

 in the urine of these experimental cases are essentially 

 the same as those observed in man. In the majority 



1 " Recherches experimentales sur les chromogfenes urinaires 

 du Groupe de ITndol' (5* M6moire) "De ITndigourie," Journ. de 

 Physiol. et de Path, gen., viii, p. 841, 1906. 



