1880.] Colouring-matters of Human Urine. 



215 



The hot water extraction of a brownish colour gave a band, o, from 

 wave-length 507 to 486. The acidulated water also gave a faint band 

 in the same part of the spectrum. The alcoholic extract gave a band 

 on each side of D, which latter were evidently similar bands to those 

 noticed in solutions of the urobilin of pleurisy treated by caustic soda, 

 or in solutions of normal urobilin treated by sodium amalgam, and in 

 the intermediate stage of Gmelin's reaction, and in the alcoholic extract 

 of human and sheep-bile pigments, and which can be prepared arti- 

 ficially by the action of sodium amalgam, in the cold, on solutions of 

 haematoin (when the pigment has been separated in the neutral state). 

 This alcoholic solution was of a red colour with transmitted light in 

 deep layers, while it was yellow in thin layers. One band, 7, extended 

 from wave-length 620 to 592, the other, £, from wave-length 585 to 569, 

 sp. 2, Chart II. With ammonia this fluid gave the spectrum seen in 

 Chart II, sp. 3. The occurrence of these latter bands shows that the 

 gall-stones contained urobilin,* as similar bands are seen by similar 

 treatment of urobilin when it is obtained from bilirubin by sodium 

 amalgam, as will be referred to again. 



Action of Chlorine on Pure Bilirubin. — The colours and changes of 

 spectrum, similar to those which accompany Gmelin's reaction, can be 

 studied with great ease by passing chlorine, well diluted with oxygen 

 (such as may be obtained in traces when black oxide of manganese is 

 heated with chlorate of potassium), into a chloroformic solution of 

 pure bilirubin. In such a solution this reagent brought about the 

 following changes in the colour and spectrum. The colour of the 

 original solution being orange, it soon changed to : — 



1. Greenish-yellow. 



2. Sap-green (band before D, 625 to 598 wave-length). 



3. Dark sap-green. 



4. Green. 



5. Bluish-green (band before D and traces of another after D). 



6. Dark blue-green (band before D, and band from wave-length 

 588—546). 



7. Indigo-blue (two bands, as before, and slight shading at F). 



8. Indigo (band /3, wave-length 620—598 ; e, 588—555 ; a, 504 — 

 482). 



9. Purplish-blue (band at F black ; e, fainter). 



10. Lilac (band at F black, e almost gone, and /3 faint). 



11. Port- wine red (/3 fainter; a as before). 



12. Reddish-yellow (a getting fainter, others gone). 



13. Light yellow (no band to be seen). 



These appearances are represented in sp. 4 to sp. 10, Chart II. 

 When pure and dry chlorine, prepared in the usual manner and 



i.e., urobilin of biliary origin. 



