1880.] 



Colouring-matters of Human Urine. 



231 



residue had a slightly green tinge, and after extraction with alcohol, 

 the alcoholic solution was seen to be a brownish -green colour, and 

 gave the spectrum already described (sp. 7). When this solution was 

 treated with sulphide of ammonium, sp. 8, Chart IV, appeared after it 

 had stood a short time (the original is seen in sp. 7), the colour of the 

 fluid changing to red. Ammonia had nothing to do with this result. 

 It therefore appears certain that human bile also contains heeniatin, but 

 in less quantity than the bile of the sheep.* 



If the curious series of bands seen in sheep-bile are due to the pre- 

 sence of hsematin, it is probable that the bands seen in the red, orange, 

 and green parts of the spectrum characteristic of the spectra of the bile 

 of other animals, are also due to its presence. In the bile of the crow 

 these bands are like those of the bile of the sheep and ox ; in that of 

 the guinea-pig the single band may be due to the darker band of hsemo- 

 chromogen ; those of the rabbit appear to be the bands of that sub- 

 stance, and I have no doubt that the presence of hsematin in the bile 

 of these animals"}" will be proved as easily as in the case of man and 

 the sheep. Of course I do not include the band at F, as that is always 

 due to the presence of urobilin. 



Action of Peroxide of Hydrogen on the Alcoholic Extract of Human 

 Bile Pigments. — When the brown- green alcoholic extract of the chloro- 

 formic residue of human bile pigment (see sp. 7, Chart IV), and which 

 was proved to contain hsematin, urobilin (of biliary origin), and other 

 pigments, was treated by peroxide of hydrogen on a white dish, the 

 colour changed from brown-green to dark-green, blue-green, blue, 

 violet, red, red-brown, and brown-yellow. At the violet stage three 

 bands were visible, sp. 9, Chart IV \% at the brown-yellow stage only 

 one, that at F, sp. 10. It was, therefore, evident that the mixture of 

 pigments could be oxidised into choletelin with great ease. 



The Absorption Hand of Serum. — The band at F in blood-serum 

 has been said to be due to lutein ;§ whether that substance is or is not 

 present, there is evidence to show that an oxidised bile pigment is 

 that which gives the band, and I have come to the conclusion, from a 

 careful examination of fresh blood-serum, obtained by letting the 

 blood of the sheep clot spontaneously, and filtering the yellow serum, 

 that it contains either choletelin or a substance like it. The serum 

 gave sp. 11, Chart IV, which shows that it still contained traces of 

 haemoglobin. The band at F 7 read from wave-length 504 to 480, 

 it was therefore nearer the red than the band of lutein, and I could 



* As proved by the presence of first band of reduced hsematin, the second being 

 just visible and overlapped by general absorption. (See 8, Chart IV.) 



t See Chart II, "Spectroscope in Medicine." 



X That at F will be represented by next spectrum, 10. 



§ Maly believed he had detected urobilin in blood, but Hoppe-Seyler thought he 

 had mistaken lutein for it. See "Hand, der Phys. und. Path. Chem. Anal.," loc. 

 sit. 



