SPECIAL BILE PIGMENTS. 435 



contrary, consider biliprasin as an intermediate step between bilirubin and bili- 

 verdin. According to them it occurs as a physiological pigment in the bladder- 

 bile of several animals, and is derived from bilirubin by oxidation. This oxida- 

 tion is brought about by an oxidative ferment existing in the bile. Bilihumin 

 is the name given by STADELER to that brownish amorphous residue which is left 

 after extracting gall-stones, with chloroform alcohol, and ether. It does not 

 give GMELIN'S test. Bilicyanin is also found in human gall-stones (HEINSIUS and 

 CAMPBELL). Cholohcematin, so-called by MACMUNN, is a pigment often occurring 

 in sheep- and ox-bile and characterized by four absorption-bands, which is 

 formed from hffimatin by the action of sodium amalgam. In the dried condition, 

 as when obtained by the evaporation of the chloroform solution, it is green, and in 

 alcoholic solution olive-brown. This pigment, which has also been found by 

 HAMMARSTEN in the bile from the musk-ox and hippopotamus, is, according' to 

 MARCHLEWSKI, identical with the crystalline bilipurpurin isolated by LOEBISCH 

 and FISCHLER from ox-bile. This latter pigment, according to MARCHLEWSKI, 

 is not a bile-pigment, but phylloerythrin, a transformation product of chlorophyll. 

 Fhylloerythrin has been detected by MARCHLEWSKI x in the excrement of cows 

 fed on green grass. 



GMELIN'S and HUPPERT'S reactions are generally used to detect the 

 presence of bile-pigments in animal fluids or tissues. The first, as a rule, 

 can be performed directly, and the presence of proteins does not interfere 

 with it, but, on the contrary, it brings out the play of colors more strik- 

 ingly. If blood-coloring matters are present at the same time, the bile- 

 coloring matters are first precipitated by the addition of sodium phos- 

 phate and milk of lime. This precipitate containing the bile-pigments 

 may be used directly in HUPPERT'S reaction, or a little of the precipitate 

 may be dissolved in HAMMARSTEN'S reagent. Bilirubin is detected in 

 blood, according to HEDENIUS, by precipitating the proteins with alcohol, 

 filtering and acidifying the filtrate with hydrochloric or sulphuric acid, 

 and boiling. The liquid becomes of a greenish color. Serum and serous 

 fluids may be boiled directly with a little acid after the addition of alcohol. 

 According to OBERMEYER and POPPER 2 the alcoholic filtrate from the 

 protein precipitation can be tested with an alcoholic solution of iodine 

 or ferric chloride. 



Besides the bile-acids and the bile-pigments, there occur in the bile 

 also cholesterin, lecithin, jecorin or other phosphatides (HAMMARSTEN), 

 palmitin, stearin, olein, myristic add (LASSAR-CoHN 3 ), soaps, ethereal 

 sulphuric adds, conjugated glucuronates, diastatic and proteolytic enzymes, 

 oxidases and catalases. Choline, and glycerophosphoric add, when they 

 are present, may be considered as decomposition products 01 lecithin. 

 Urea occurs, though only in traces, as a physiological constituent of human, 



1 MacMunn, Journ. of Physiol., 6; Loebisch and Fischler, Wien. Sitzungsber., 112 

 (1903); Marchlewski, Zeitschr. f. physiol. Chem., 41, 43, and 45; Hammarsten, ibid., 

 43, and investigations not published. 



2 Hedenius Upsala Lakaref. Forh., 29 and Maly's Jahresber., 24; Obermeyer and 

 Popper, Wien. med. Wochenschr., 60. 



8 Zeitschr. f. physiol. Chem., 17; Hammarsten, ibid., 32, 36 and 43. 



