250 ORIGIN OF BILE-PIGMENTS. 



One point still remains for discussion. It has been seen that 

 bile-pigments can be formed from those of the blood in outlying 

 parts of the body without the intervention of the liver. Are we 

 therefore to suppose that the liver is similarly inoperative in that 

 increased formation and excretion of bile-pigments, both in the 

 urine and bile, which result from the intravascular injection of 

 haemoglobin ? Opinions have differed on this point. It is on the 

 whole more probable that the liver is in all cases the chief factor 

 in the conversion. The normal production of bile-pigments is 

 entirely due to hepatic activity, for no pigments are accumulated 

 in the body after extirpation of the liver in frogs or its exclusion 

 from the circulation in birds. 1 This accords with the fact that 

 apparently the larger part of the pigments resulting from the in- 

 jection of haemoglobin pass out in the bile while but little goes 

 into the urine. If this is so, how shall we account for the excre- 

 tion of the latter and smaller portion by the kidneys ? It is 

 known that the liver is peculiarly liable under the influence of 

 but slight operative and other influences to pass some of its pro- 

 ducts over into its lymphatics whence they make their way into 

 the blood-vessels and may hence be excreted by the kidneys. 

 Very slight obstruction of the bile-duct suffices to produce this 

 result, and it has been observed that the bile formed after injec- 

 tions of haemoglobin is unusually viscid. The views here put 

 forward (see also 477) are further in complete accord with the 

 facts that hsematin (haemochromogen) readily loses iron and 

 yields hsematoporphyrin C3 2 H 32 N 4 05 which differs but slightly in 

 composition from bilirubin (Ci 6 Hi 8 N 2 3 )2, and that it is precisely 

 in bile and very largely in the liver that we meet with consider- 

 able quantities of iron in some as yet not well-known form. 2 

 The possible function of the spleen as an organ in which a con- 

 siderable disintegration of red corpuscles takes place, in providing 

 the material requisite for the formation of bile-pigments by the 

 liver has been already discussed 3 ( 478). 



As already stated herbivorous bile, as of ox and sheep, frequently 

 shows absorption bands even when fresh. These are regarded by 

 MacMunn as due to a substance to which he has given the name 

 cholo-hsematm since it occurs in bile and, as the action of sodium- 

 amalgam shows, is related to hsematin. The bands more usually seen 

 are three, two near D and one near J.* 



1 Stern, Arch. f. exp. Path. u. Pharm. Bd. xix. (1885), S. 39. Minkowski u. 

 Naunyn, Ibid. Bd.'xxi. (1886), S. 1. 



2 Zaleski, Zt. f. physiol. Chem. Bd. x. (1886), S. 453. See also Virchow's Arch. 

 Bd. civ. (1886), S. 91. 



3 According to Schafer, Proc. Physiol. Soc.. 1890, No. 3 (see Jl. of Physiol. Vol. 

 XL), there is no evidence of any discharge of haemoglobin from the spleen in the 

 blood of the vein of this organ. 



* Jl. of Physiol. Vol. vi. (1884), p. 24. 



