160 PHYSIOLOGICAL CHEMISTRY. 



who have other views. BALDI claims that the formation of bile- 

 acids does not take place only in the liver, but in the entire 

 organism, and he claims to have detected bile-acids in the normal, 

 circulating blood of different organs. 



It has been indubitably proved that the bile-pigments may be 

 formed in other organs besides the liver, for, as is generally ad- 

 mitted, the coloring matter haematoidin, which occurs in old blood 

 extravasations, is identical with the bile-pigment bilirubin (see page 

 80). LATSCHENBERGER has also observed in horses, under physio- 

 logical conditions, a formation of bile-pigments from the blood- 

 coloring matters in the tissues. Also the occurrence of bile- 

 pigments in the placenta seems to depend on their formation in 

 that organ, while the occurrence of small quantities of bile-pigments 

 in the blood-serum of certain animals probably depends on an ab- 

 sorption of the same. 



Though the bile-pigments may be formed in other organs, it 

 still seems that their formation under physiological conditions 

 occurs mainly in the liver. By experimenting on pigeons STERN 

 was able to detect bile-pigments in the blood-serum five hours after 

 tying the biliary passages alone, while after tying all the vessels of 

 the liver and also the biliary passages no bile-pigments could be 

 detected either in the blood or the tissues of the animal, which was 

 killed 10-12 hours after the operation. MINKOWSKI and NAUNYN 

 have also found that poisoning with arseniuretted hydrogen pro- 

 duces a liberal formation of bile-pigments and the secretion, after a 

 short time, of a urine rich in biliverdin in previously healthy geese. 

 In geese with extirpated livers this does not occur. The great im- 

 portance of the liver in the formation of bile-pigments seems to be 

 settled, even though these bodies may be formed also in other organs. 



In regard to the materials from which the bile-acids are pro- 

 duced, it may be said with certainty that the two components, 

 glycocoll and taurin, which are both nitrogenized, are formed 

 from the protein bodies. In regard to the origin of the non-nitro- 

 genized cholalic acid, which was formerly considered as originat- 

 ing from the fats, we know nothing positively. 



The blood -coloring matters are considered as the mother- 

 substance of the bile-pigments. If the identity of hsematoidin 

 and bilirubin were beyond doubt, then this view might be consid- 



