TI1K LI V Eli. ir>f; 



The neutral solutions of these coloring matters are, according to 

 STOKVIS, bluish green or steel-blue with a beautiful blue fluores- 

 cence. The alkaline solutions are green and have no marked 

 fluorescence. The neutral and alkaline solutions show three ab- 

 sorption-bands, one sharp and dark in the red between G and D, 

 nearer to (7; a second, less defined, covering D\ and a third, form- 

 ing only a faint shadow, in the green, exactly in the middle, 

 between D and E. The strongly-acid solutions are violet-blue and 

 show two bands, described by JAFEE, between the lines G and E, 

 separated from each other by a narrow space near D. The next 

 oxidation step after these blue coloring matters gives a red pig- 

 ment, and lastly a yellowish-brown pigment, called choletelin by 

 MALY, which shows no absorption-spectrum. 



Bilirubin is best prepared from gall-stones of oxen, these con- 

 cretions being very rich in bilirubin-calcium. The finely-powdered 

 concrement is first exhausted with ether and then with boiling 

 water, so as to remove the cholesterin and bile-acids. The 

 powder is then treated with hydrochloric acid, which sets free the 

 pigment. Wash thoroughly with water and alcohol, dry, and 

 extract continuously with boiling chloroform. After distilling the 

 chloroform from the solution, treat the powdered residue with 

 absolute alcohol to remove the bilifuscin ; dissolve the remaining 

 bilirubin in a little chloroform ; precipitate it from this solution by 

 alcohol, and do this several times if necessary. The bilirubin is 

 finally dissolved in boiling chloroform and allowed to crystallize on 

 cooling. The quantitative estimation of bilirubin may be made by 

 the spectro-photometrical method, according to the steps suggested 

 for the blood-coloring matters, 



Biliverdin, 8 H 9 N0 2 . This body, which is formed by the oxida- 

 tion of bilirubin, occurs in the bile of many animals, in vomited 

 matter, in the placenta of the bitch (?), in the shells of birds' eggs, 

 in the urine in icterus, and sometimes in gall-stones, although in 

 very small quantities. 



Biliverdin is amorphous, or at least it has not been obtained in 

 well-defined crystals. It is insoluble in water, ether, and chloro- 

 form (this is true at least for the artificially-prepared biliverdin, 

 while the green pigment of ox-bile is soluble in chloroform, accord- 

 ing to MACMUNN), but is soluble in alcohol or glacial acetic 

 acid, showing a beautiful green color. It is dissolved by alkalies 

 giving a brownish-green color, and this solution is precipitated by 



