328 DIGESTION. 



Composition of Meconium (Frerichs) : 



Biliary resin 15-6 



Common fat and cholesterin 15-4 



Epithelium, mucus, pigment, and salts . .69- 



In the foetus, therefore, the main purpose of the secretion 

 of bile must be the purification of the blood by direct 

 excretion, i.e., by separation from the blood, and ejection 

 from the body without further change. Probably all the 

 bile secreted in foetal life is incorporated in the meconium, 

 and with it discharged, and thus the liver may be said to 

 discharge a function in some sense vicarious of that of the 

 lungs. For, in the foetus, nearly all the blood coming from 

 the placenta passes through the liver, previous to its dis- 

 tribution to the several organs of the body; and the 

 abstraction of carbon, hydrogen, and other elements of bile 

 will purify it, as in extra-uterine life it is purified by the 

 separation of carbonic acid and water at the lungs. 



The evident disposal of the foetal bile by excretion, makes 

 it highly probable that the bile in extra-uterine life is 

 also, at least in part, destined to be discharged as 

 excrementitious. But the analysis of the faeces of both 

 children and adults shows that (except when rapidly dis- 

 charged in purgation) they contain very little of the bile 

 secreted, probably not more than one-sixteenth part of its 

 weight, and that this portion includes only its colouring, 

 and some of its fatty matters, but none of its essential 

 principle, the bilin. All the bilin is again absorbed from 

 the intestines into the blood. But the elementary compo- 

 sition of bilin (see p. 325) shows such a preponderance of 

 carbon and hydrogen, that it cannot be appropriated to 

 the nutrition of the tissues ; therefore, it may be presumed 

 that after absorption, the carbon and hydrogen of the 

 bilin combining with oxygen, are excreted as carbonic 

 acid and water. The destination of the bile is, on this 



