222 



Dr. C. A. MacMunn. Researches into the [Dec. 16, 



latter it was seen to be yellow with, a greenish tinge in very thin 

 strata. In deep layers it gave a band covering D, but in shallow 

 layers one at F. (Chart II, sp. 15.) Treated with caustic soda it 

 gave sp. 14,* Chart II, the colour of the fluid becoming light green- 

 yellow. This is the same spectrum as that got by the action of 

 caustic soda on bilirubin treated by sodium amalgam. It will be 

 noticed that the band at F becomes replaced under the action of 

 caustic soda, by another of less intensity of shading and nearer the- 

 red end of the spectrum. 



Zinc chloride produced a precipitate soluble in alcohol forming a 

 green solution, and then the band at F was seen to be narrowed, and 

 nearer the red ; it produced a spectrum in other particulars like that 

 got by the action of caustic soda. Chart II, sp. 16. 



Hydrochloric add produced a turbidity, changing the fluid to dark 

 red, which became clear brown-red with more alcohol; this solution 

 gave sp. 17 in deep layer, while in shallower layer sp. 18 appeared. 



Sulphuric acid produced a dark-red fluid, giving almost the same 

 spectrum. 



From these observations it was quite evident that the same kind of 

 urobilin was present as that got by the action of sodium amalgam on 

 bilirubin. 



Urobilin was absent from the bile in a case of thrombosis of the- 

 portal vein, and this observation supports the view that it is formed 

 in the intestine. 



Urobilin in the Bile of the Pig. — This bile was golden -yellow, and was 

 treated as in the case of human bile. The chloroformic solution was 

 yellow, and left a chrome-yellow residue, which was entirely soluble in 

 rectified spirit, forming a yellow solution. This gave, in deep layers, 

 general absorption, and in thin strata a band from wave-length 507 to- 

 482. 



Zinc chloride produced a precipitate soluble in alcohol, and an 

 abrupt shading commencing at wave-length 510. But in a thinner 

 layer a band was seen detached in the usual position, but owing to the 

 general absorption its violet edge was indistinct. When the alcoholic 

 solution was treated with acetic acid a band, a, from wave-length 507 

 to 478 was visible, the colour of the solution being greenish-yellow. 



The alcoholic solution treated with caustic soda got pale yellow, and 

 gave the usual band from wave-length 512 to 488. 



This observation afforded positive proof of the presence of urobilin 

 in the bile of the pig. 



Urobilin in Ox-bile. — This bile was brown in deep, but yellow in 

 shallow strata. It gave sp. 2, Chart III, which is of great interest, as 

 a similar spectrum can be produced artificially from hcematin, to which I 



* This map is made to represent two spectra, as both were exactly similar (see- 

 explanation of Chart II). 



