AND OF THE BILE. 63 



ployed in the production of blood, must, when re- 

 turned through the intestines into the circulation, in 

 like manner yield to the influence of the oxygen 

 which they meet. The bile is a compound of soda, 

 the elements of which, with the exception of the 

 soda, disappear in the body of a carnivorous animal. 



In the opinion of many of the most distinguished 

 physiologists, the bile is intended solely to be ex- 

 creted ; and nothing is more certain, than that a 

 substance containing so very small a proportion of 

 nitrogen can have no share in the process of nutri- 

 tion or reproduction of organised tissue. But 

 quantitative physiology must at once and decidedly 

 reject the opinion, that the bile serves no purpose 

 in the economy, and is incapable of further change. 



No part of any organised structure contains soda ; 

 only in the serum of the blood, in the fat of the 

 brain, and in the bile, do we meet with that alkali. 

 When the compounds of soda in the blood are con- 

 verted into muscular fibre, membrane, or cellular 

 tissue, the soda they contain must enter into new 

 combinations. The blood which is transformed into 

 organised tissue gives up its soda to the compounds 

 formed by the metamorphoses of the previously 

 existing tissues. In the bile we find one of these 

 compounds of soda. 



Were the bile intended merely for excretion, we 

 should find it, more or less altered, and also the 

 soda it contains, in the solid excrements. But, 

 with the exception of common salt, and of sulphate 



