96 BILE. 



already shown (in vol. 1, p. 317) that, in all probability, it is 

 formed from the blood-pigment ; we shall, therefore, not again 

 revert to the grounds on which this possibility or probability rests, 

 but will merely observe that, if cholepyrrhin be actually a product 

 of the metamorphosis of hsematin, the process, at all events in 

 the normal state, takes place in the liver. It appears no mere 

 image of the fancy, to regard the distorted, speckled, irregular 

 blood-corpuscles in the portal blood of fasting animals, as cells that 

 are growing old ; for, at all events, we find that the blood-cells 

 leaving the liver by the hepatic veins, exhibit precisely those 

 characters which we ascribe to young blood-cells ; hence the cells 

 of the portal blood do not undergo rejuvenescence in the liver, 

 but suffer disintegration in that gland, and their remains are in 

 part (the iron, for instance) applied to the formation of new 

 blood-corpuscles, and in part are converted into excreted matters ; 

 hence it is very conceivable, that the heematin loses its iron and 

 becomes converted into cholepyrrhin, which is mixed in the biliary 

 canals with the other constituents of the bile. In instituting 

 several comparative analyses with both kinds of blood, I found in 

 600 grammes of portal blood-cells, 0*384 of a gramme of metallic 

 iron, and in the corresponding 760 grammes of blood-cells from the 

 hepatic veins, 0*333 of a gramme of iron. Hence, however great 

 may be the errors of observation, this much is certain, that the 

 iron of the decaying blood-corpuscles of the portal vein is more 

 than sufficient for the requirements of the young cells of the 

 hepatic venous blood. If we regarded the view as tenable, that 

 the quantity of iron in the blood-corpuscles, or in the heematin, 

 has any influence on the colour, we would here notice the difference 

 of tint presented by the blood of the portal and of the hepatic 

 veins. F. C. Schmid has directed attention to the dark brown, 

 sometimes velvet-like black colour of the clot of portal blood ; 

 the corpuscles of the blood of the hepatic veins always appear of 

 an intense purplish violet colour, when seen in thin layers a 

 colour which I have never observed in portal blood, nor to the 

 same degree in any other venous blood. Whether this deficiency 

 of iron in the blood of the hepatic veins be simply dependent on 

 errors of observation, or whether the missing iron must be 

 regarded as having passed into the bile, are points which I will not 

 venture to decide, although 1 have made three experiments which 

 coincided very well with one another. Since, however, iron has 

 been so often found in the bile, the difference in the numerical 

 results is probably dependent on the nature of the changes going 



