202 SOURCE OF THE BILE. 



through the additions made to it by absorption of matters from the stom- 

 ach and intestine. We may overlook for the present those 



beparation or '.** 



the portal blood contributions it receives from the veins of the spleen and oth- 

 m the liver. er S0urce3> Regarding it, therefore, as systemic venous blood, 

 charged with certain of the products of digestion, it enters the liver to be 

 acted upon by that gland. The first effect upon it is, in a chemical point 

 of view, well marked. The stream which sets off to the general circula- 

 tion through the hepatic veins may be said to carry away the whole of the 

 nitrogenized material ; for the bile, which is at this point parted out and 

 sent back to the intestine through the biliary ducts, does not contain more 

 than 4 per cent, of nitrogen, and this exclusive of the water which im- 

 Course and P arts * ^ ^ ts liquid condition. Arrived in the intestine, a rep- 

 separation of etition of the same process of partition takes place, the color- 

 ing matter, which contains nearly the whole of this residual ni- 

 trogen, being dismissed with the faeces, and the remaining hydrocarbon 

 taken up by the lacteals along with other fats. 



The first duty of the liver is therefore a separation of the nitrogenized 

 principles of the portal blood, which are forthwith carried into the gen- 

 eral circulation through the hepatic veins and the vena cava. The result 

 is, that there is returned to the intestine a sulphureted hydrocarbon, still 

 containing so much* nitrogen as to form a very unstable product, prone 

 even to spontaneous decomposition. In the intestine its nitrogen is whol- 

 ly removed from it, and the combustible hydrocarbon is then absorbed. 



The portal blood, regarded under the aspect here presented, is obvi- 

 From what ous ty composed of two constituents : 1st. Systemic venous 

 source is the blood ; 2d. Matters obtained from the digestive cavity. We 



bile derived? next inquire from which O f these ^ ft\ Q is rea H y derived. 



Besides the presumptive evidence arising from the consideration that 

 if the bile originated from matters which had been just absorbed from 

 the digestive cavity, it would be inconceivable why it should be returned 

 forthwith thereto, its quality of extreme instability marks it out; as a sub- 

 stance fast approaching to final disorganization and decomposition. It 

 bears no aspect of a histogenetic or formative body, but, on the contrary, 

 it is on the downward course. We should scarcely expect to recognize 

 it as a primary product of the digestive action, but should seek its prob- 

 able origin in some source of decay. 



Whatever weight may attach to such considerations, we have, in addi- 

 tion, direct evidence which places the source of the bile beyond doubt by 

 referring it to the systemic venous blood, and not to the matters just ob- 

 tained from the digestive cavity. 



During foetal life, the digestive organs are in an inactive state, but the 

 liver, which is largely developed, discharges its secretion into the intes- 

 tine. This secretion, which is known as the meconium, is a true bile, as 

 the following analysis proves. 



