CH. XXXIII.] 



THE BILE 



509 



in the elaboration of bile pigment, it does not proceed so far as to 

 liberate haemoglobin from the corpuscles. ISTo free haemoglobin is 

 discoverable in the blood plasma in the splenic vein. 



The amount of bile secreted is differently estimated by different 

 observers ; the amount secreted daily in man varies from 500 c.c. to 

 a litre (1000 c.c.). 



The constituents of the bile are the bile salts proper (tauro- 

 cholate and glycocholate of oda), the bile pigments (bilirubin, 

 biliverdin), a mucinoid substance, small quantities of fats, soaps, 

 cholesterin, lecithin, urea, and mineral salts, of which sodium chloride 

 and the phosphates of iron, calcium, and magnesium are the most 

 important. 



Bile is a yellowish, reddish-brown, or green fluid, according to the 

 relative preponderance of its two chief pigments. It has a musk-like 

 odour, a bitter-sweet taste, and a neutral or faintly alkaline reaction. 



The specific gravity of human bile from the gall-bladder is 1026 

 to 1032; that from a fistula, 1010 to 1011. The greater concentra- 

 tion of gall-bladder bile is partly but not wholly explained by the 

 addition to it from the walls of that cavity of the mucinoid material 

 it secretes. 



The amount of solids in bladder bile is from 9 to 14 per cent., in 

 fistula bile from 1'5 to 3 per cent. The following table shows that this 

 low percentage of solids is almost entirely due to want of bile salts. This 

 can be accounted for in the way first suggested by Schiff that there 

 is normally a bile circulation going on in the body, a large quantity 

 of the bile salts that pass into the intestine being first split up, then 

 reabsorbed and again secreted. Such a circulation would obviously 

 be impossible in cases where all the bile is discharged to the exterior. 



The following table gives some important analyses of human bile : 



