CHEMICAL BASIS OF THE ANIMAL BODY. 251 



granules and flakes which are of a yellow or orange colour and yield 

 an intense Gmelin's reaction \ Finally by the action of phenylhydrazin 

 on hsematin and on bilirubin products are obtained which in each case 

 exhibit a similar and marked play of colours under the action of fuming 

 (yellow) nitric acid 2 . 



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 intra vascular 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 3 . This 

 accords with the fact that apparently the larger part of the pigments 

 resulting from the injection of haemoglobin pass out in the bile while 

 but little goes into the urine. If this is so, how shall we account for 

 the excretion of the latter and smaller portion by the kidneys 1 It is 

 known that the liver is peculiarly liable under the influence of but 

 slight operative and other influences to pass some of its products 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 injections of haemoglobin is unusually viscid. 

 The views here put forward (see also 477) are further in complete 

 accord with the facts that haematin (hsemochromogen) readily loses 

 iron and yields hsematoporphyrin C 32 H 32 N 4 O 5 which differs but slightly 

 in composition from bilirubin (C 16 H 18 N 2 O 3 ) 2 , and that it is precisely in 

 bile and very largely in the liver that we meet with considerable 

 quantities of iron in some as yet not well-known form 4 . The possible 

 function of the spleen as an organ in which a considerable dis- 

 integration of red corpuscles takes place, in providing the material 

 requisite for the formation of bile-pigments by the liver has been 

 already discussed 5 ( 478). 



1 Latschenberger, Zt. f. Veterinarkunde, Bd. i. (1886), S. 47. Monatsh. f. Chem. 

 Bd. ix. (1888), S. 52. 



2 Filehne, Verhand. d. Congresses f. inn. Med. Wiesbaden, Eef. in Centralb. f. 

 klin. Med, 1888. 



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

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



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

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



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

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

 blood of the vein of this organ. 



