LECT. IV. BY LYMPHATICS AND LACTEALS. 85 



Absorption by Lymphatics and Lacteals. On the other 

 hand, that absorption can be also effected by the lymphatic 

 vessels, is a fact too well known and too evident, to render 

 a demonstration of it necessary. Kill an animal two or 

 three hours after it has taken food, expose the intestines, 

 and carefully examine the mesentery, and you will find that 

 the chyliferous vessels are filled with a milky liquid analo- 

 gous to that which flows abundantly from the thoracic duct, 

 which is the principal reservoir into which these vessels dis- 

 charge their contents. This liquid is the chyle which, by 

 the act of digestion, is formed in the intestine, from which 

 it is absorbed by the chyliferous vessels. How many ex- 

 amples has pathological anatomy furnished us with, in 

 which these vessels have been found full of pus, by reason 

 of their proximity to suppurating parts ! The chyliferous 

 and lymphatic vessels are, therefore, endowed with the 

 power of absorption. 



Physical Condition of Absorption.* In a word, absorption 

 is always effected under the following conditions : 



1st. A vessel with organic sides or walls. 



2dly. An anterior liquid capable of being imbibed by the 

 tissue composing the walls. 



3dly. An internal liquid, also capable of being imbibed 

 by the walls ; of intermixing with the exterior liquid ; and 

 of circulating in the vessel with more or less rapidity. 



Nothing, consequently, can be more physical than a 

 phenomenon thus constituted. 



I will demonstrate, by an experiment, the truth of this 

 assertion. Here is a long piece of vein taken from a large 

 animal ; it is attached at one end to a tube connected with 

 an opening in the lower part of the side of a glass bottle ; 

 the other extremity is tied to a small bent glass tube, fur- 

 nished with a stop cock. I fill the bottle, and, consequently, 



