FORMATION OF BILE PIGMENTS. 443 



settled beyond a doubt, then this view might be considered as proved. 

 Independently, however, of this identity, which is not admitted by 

 all investigators, the view that the bile-pigments are derived from the 

 blood-coloring matters has strong arguments in its favor. It has been 

 shown by several experimenters that a yellow or yellowish-red pigment 

 can be formed from the blood-coloring matters, which gives GMELIN'S 

 test, and which, though it may not form a complete bile-pigment, is 

 at least a step in its formation (LATSCHENBERGER) . The previously 

 mentioned relationship between the blood and bile-pigments must be 

 recalled, and the formation of bilirubin from the blood-pigments is 

 shown, according to the unanimous observations of several investi- 

 gators, 1 by the fact that the appearance of free haemoglobin in the plasma, 

 produced by the destruction of the red corpuscles by widely differing 

 influences (see below) or by the injection of haemoglobin solution, causes 

 an increased formation of bile-pigments. The amount of pigments in 

 the bile is not only considerably increased, but the bile-pigments may 

 even pass into the urine under certain circumstances (icterus). After 

 the injection of haemoglobin solution into a dog either subcutaneously 

 or in the peritoneal cavity, STADELMANN and GORODECKI 2 observed an 

 increase of 61 per cent in the secretion of pigments by the bile, which 

 lasted for more than twenty-four hours. Recently BRUSCH and YOSH- 

 IMOTO, 3 by quantitative estimations of the bile-pigments and urobilin 

 in animals with bile fistulas with ligated ductus choledochus, have 

 shown the increased formation of bile-pigments after the injection of 

 known amounts of haematin, and in this manner further proved the 

 genetic relationship between the bile-pigments and hsematin. 



If bilirubin, which contains no iron, is derived from ha3matin, which 

 contains iron, then iron must be split off. The question in what form or 

 combination the iron is split off is of special interest, and also whether 

 it is eliminated by the bile. This latter does not seem to be the case, 

 at least to any great extent. In 100 parts of bilirubin which are eliminated 

 by the bile there are only 1.4-1.5 parts iron, according to KUNKEL, while 

 100 parts haematin contain about 9 parts iron. MINKOWSKI and BASE- 

 RiN 4 also found that the abundant formation of bile-pigments occurring 

 in poisoning by arseniureted hydrogen does not increase the quantity 

 of iron in the bile. The quantity apparently does not seem to correspond 

 with that in the decomposed blood-coloring matters. It follows from the 



1 See Stadelmann, Der Icterus, etc., Stuttgart, 1891. 



2 See Stadelmann, ibid. 



3 Zeitschr. f. exp. Path. u. Therap., 8. 



4 Kunkel, Pfltiger's Arch., 14; Minkowski and Baserin, Arch. f. exp. Path. u. 

 Pharm., 23. 



