THE LIVER. SECRETION OF BILE. 593 



when the secreting action of the liver is suspended, are not in the same condition 

 with those which are received back into it after being submitted to that action ; 

 and that the liver, therefore, not merely separates them, but exercises a certain 

 transforming agency upon them, as it is. known to effect upon other constituents 

 of the blood which pass through it ( 472). 



632. Bile is a viscid, somewhat oily-looking liquid, of a greenish-yellow color, 

 and very bitter taste, followed by a sweetish after-taste. It is readily miscible 

 with water, and its solution froths like one of soap. The proportion of solid 

 matter which it contains is usually from 9 to 12 per cent. ; and nearly the whole 

 of this consists of substances peculiar to Bile. The following are the general 

 results of the analyses made by Berzelius, of Human Bile, and of that of the 

 Ox: 



MAN. Ox. 



Water. . ,-, ; .-,-:-. .^...^ .v --.'.., v^l : . 90.44 92.84 



Biliary matter . . - .-. .- 4 * ; 8.00 5.00 



Mucus of the gall-bladder . . . ,' .. .30 .23 



Soda 41 



Chloride of sodium, and extractive . '.'.* / '* .74 1.50 



Phosphates and sulphates of soda and lime . . .11 .43 



100.00 100.00 



In the Biliary matter, according to the researches of Strecker (which are un- 

 doubtedly the most accurate and satisfactory that have been hitherto made), the 

 following substances may be distinguished : Glycocholic acid (the cholic of 

 Strecker and of many former authors), which is its principal organic constitu- 

 ent, united for the most part with soda, but with small and variable quantities 

 of potash and ammonia ( 68); Taurocholic acid (the choleic acid of Strecker, 

 also known as bilin), which also is united with alkaline bases ( 69) ; Choles- 

 terin ( 43), the proportion of which in healthy bile is usually very small; 

 and Bile-pigments ( 70), of which also the proportion is usually small. It is 

 remarkable that, notwithstanding the comparatively minute proportion in which 

 these two last substances exist in ordinary bile, Cholesterin should usually be 

 the principal ingredient of the biliary concretions which are frequently found 

 in the gall-bladder and bile-ducts ; and that the bile-pigment should also occasion- 

 ally accumulate, so as to form solid masses which consist of little else. 1 It 

 would appear from this that the peculiar resinous acids of the bile are far more 

 readily re-absorbed than are its other ingredients; and this corresponds with 

 the results of experiments upon the contents of the alimentary canal, which 

 show that, whilst the color of the feces is chiefly due to the presence of bile- 

 pigment, the conjugated acids are scarcely to be recognized. The quantity of 

 Bile ordinarily secreted by the liver, the circumstances which favor or retard 

 its production, the mode in which it is discharged into the intestine, and the 

 purposes which it answers in the digestive process, have all been considered in 

 a previous chapter ( 453, 454) ; and it now only remains to point out, that 

 the fact of the performance of this operation during foetal life, as shown by the 

 accumulation of biliary matter in the intestinal canal at birth ( 629), is a clear 

 indication of the truly excrementitious matter of this product. Its separation 

 from the blood during intra-uterine life can have no reference to the process of 

 digestion, which is not then taking place; nor can it be subservient to that of 

 respiration, which has not commenced ; but it must be regarded, like the elimi- 



1 The cholesterin and bile-pigment (which forms a definite compound with lime) are 

 held in solution in healthy bile by the tauro-cholic acid. Hence it seems likely that the 

 production of the biliary concretions which are composed of these substances, is due either 

 to a relative deficiency of tauro-cholic acid, or to a decomposition of that substance in the 

 gall-bladder. 



38 



