BILE-PIGMENT. 317 



disturbances of the function of the liver this pigment very frequently 

 presents itself in the urine, and may usually be recognised by a 

 brownish red or cinnamon brown, dark colour, which sometimes, 

 if the urine be allowed to stand till it become acid (Scherer), passes 

 into a dark green tint. Sometimes, however, it is also absent in 

 this fluid while other biliary constituents are present in it. Occa- 

 sionally, in perfect suppression of the biliary secretion as for 

 instance in true granular liver, when the urine throws down an 

 intense scarlet sediment no trace either of bile-pigment or of 

 cholic acid can be detected. 



Origin. As we are still unable to obtain an empirical formula 

 for the composition of bile-pigment, chemistry affords us no infor- 

 mation regarding the origin of this substance. The opinion has 

 certainly long been advanced that bile-pigment was formed from 

 haematic in consequence of the greenish shades of colour which 

 extravasated blood usually exhibits, as for instance under the skin 

 after contusions, in the sputa of patients with pneumonia, and 

 sometimes in typhous stools. However plausible this view may 

 appear when we examine the blood-corpuscles of portal blood 

 and find the colouring matter essentially changed in them, yet 

 physiological facts are still wanting to support it. Virchow,* 

 by his physiological investigations, has with much ingenuity pointed 

 out the way which the chemist must proceed in order to decide the 

 question in reference to this pigment. He was the first to draw 

 attention to the red crystals which are found within the animal 

 organism and which evidently arise from stagnating bile, and to show 

 that in their reactions they take an intermediate place between 

 heematoidin and bile -pigment., forming a transition stage between 

 these two pigments. 



Uses. Whether the bile-pigment takes any part in the process 

 of digestion, and what are its uses in the intestinal canal, are 

 questions which for the present must remain altogether undecided. 

 The fact that it undergoes so decided an alteration in the intestinal 

 canal leads us ideologically to infer that it fulfils some special 

 object. 



These crystals, which are possibly identical with the bilifulvin 

 found by Berzelius in bile which had already undergone change 

 (Pel tauri inspissatum), have been found on the wall of echinococcus- 

 sacs, which, in consequence of ruptures and partial resorption of the 

 walls, communicated with the biliary ducts. 



The facts now in our possession seem to indicate that the liver 

 * Arch. f. pathol. Anat. u. s. w. Bd. 1, S. 427-431. 



