CHAP. IV.] 



RELATIONS OF CHOLETELIN. 



331 



acids, on the other, were identical in other words that choletelin 

 and hydroftilirubin were one and the same substance. Heynsius 

 accounted for the same body being produced, under such opposite 

 circumstances, on the hypothesis that it was a product not of 

 oxidation or of reduction, but of the splitting-up of the molecule 

 of bilirubin or biliverdin : it being true that the decomposition 

 of some very complex substances sometimes occurs under circum- 

 stances which are widely different. Liebermann shewed, how- 

 ever, that when he converted bilirubin into hydrobilirubin the 

 product amounted to 95g of the bilirubin employed, whilst when 

 he converted it into choletelin, the product obtained only represented 

 72* of the bilirubin employed. A comparison of the elementary 

 composition of bilirubin, hydrobilirubin and of choletelin at once 

 demonstrate's the wide difference which exists between the two 

 latter substances as well as in their relations to bilirubin. 



COMPOSITION OF BILIRUBIN, CHOLETELIN AND HYDROBILIRUBIN. 



The following tabular statement brings out very clearly the 

 points of difference in physical characters between hydrobilirubin 

 and choletelin. 



Hydrobilirubin. 



Produced from bili- By reduction, 

 rubin. 



Choletelin. 

 By oxidation. 



The spectrum of a neu- Exhibits an absorption No absorption band. 

 tral alcoholic solu- band between A501 '2 The absorption of 



tion. 



and A486-1. 



light between A501'2 

 and X486-1 is ^th 

 of that observed in 

 the case of hydro- 

 bilirubin, cceteris pa- 

 ribus (Vierordt). 



Colour of an acid solu- Garnet-red to rose-red, Yellow, 

 tion. according to concen- 



tration. 



