162 PHYSIOLOGICAL CHEMISTRY. 



though in reality it is probably more complicated. The question 

 in what form or combination the iron is split off is of special inter- 

 est, and also whether it is eliminated by the bile. This latter does 

 not seem to be the case. In 100 parts of bilirubin which are elimi- 

 nated 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 BASERIN have also found that the abundant 

 formation of bile-pigments occurring in poisoning by arseniuretted 

 hydrogen does not increase the quantity of iron in the bile. The 

 quantity apparently does not correspond with that in the decom- 

 posed blood-coloring matters. 



On the contrary, it seems as if the iron, at least for a time, is 

 retained by the liver as a pigment rich in iron. Such a pigment 

 containing iron, which was formed by the decomposition of 

 haemoglobin, was observed by NAUNYN and MINKOWSKI in the 

 livers of birds, in arseniuretted hydrogen icterus. LATSCHEN- 

 BERGER claims that a yellow or yellowish red pigment, " choleglobin" 

 is derived from the blood-coloring matters, and acts as a step in the 

 formation of the bile-pigments; and besides this he mentions an- 

 other body consisting of dark grains and containing iron, which he 

 designates as melanin. NEUMANN has observed in blood extrav- 

 asations, besides hsematoidin, a pigment containing iron, for which 

 he has proposed the name lic&matosiderin. 



An absorption of bile from the liver by the lymphatic vessels 

 and the passage of the bile-constituents into the blood and urine 

 occurs in retarded discharge of the bile, and usually in the differ- 

 ent forms of hepatogenic icterus. But bile-pigments may also pass 

 into the urine under other circumstances, especially in animals 

 where a solution or destruction of the red blood-corpuscles takes 

 place through injection of water or a solution of biliary salts, through 

 poisoning by ether, chloroform, arseniuretted hydrogen, or toluylen- 

 diamin; and in other cases. This occurs also in man in grave 

 infectious diseases. We have therefore a second form of icterus, 

 in which the blood-coloring matters are transformed into bile- 

 pigments elsewhere than in the liver, blood, and tissues a 

 hcematogenic, chemical, or arihepatogenic icterus. Only bile-pig- 

 ments occur in the urine in these cases, while in hepatogenic 

 icterus the urine contains the bile-pigments and bile-acids at the 



