THE BILE MECONIUM. 263 



gen from the blood ; and its adaptation to this purpose is well 

 illustrated by the peculiarities attending its secretion and dis- 

 posal in the foetus. During intra-uterine life, the lungs and 

 the intestinal canal are almost inactive ; there is no respiration 

 of open air or digestion of food ; these are unnecessary, because 

 of the supply of well-elaborated nutriment received by the 

 vessels of the foetus at the placenta. The liver, during the 

 same time, is proportionally larger than it is after birth, and 

 the secretion of bile is active, although there is no food in the 

 intestinal canal upon which it can exercise any digestive 

 property. At birth, the intestinal canal is full of thick bile, 

 mixed with intestinal secretion ; for the meconium, or faeces of 

 the fcetus, are shown by the analyses of Simon and of Frerichs 

 to contain all the essential principles of bile. 



Composition of Meconium (Frerichs) : 



Biliary resin, ....... 15.6 



Common fat and cholesterin, .... 15.4 



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



100. 



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

 bile must be the purification of the blood by direct excretion, 

 i. e. y 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 dis- 

 charged, 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 distribution 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 discharged in purgation) they con- 

 tain very little of the bile secreted, probably not more than 

 one-sixteenth part of its weight, and that this portion includes 

 only its coloring, 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 com- 

 position of bilin (see p. 261) shows such a preponderance of 

 carbon and hydrogen, that it cannot be appropriated to the 

 nutrition of the tissues; therefore, it maybe presumed that 



