204 



CHAP. Wl.Mesenteric Absorbents. 



1. DO these vessels merely serve the purposes of tubes, or 

 have they a function superadded to their mechanical construction? 



2. if the absorbents of the mesentery had a relation of the 

 mechanical kind, and no other, with the contents of the intestines, 

 there appears no reason why the peculiar fluid . which is found in 

 them should be taken up, rather than some others which also make 

 a part of the intestinal contents. There are sufficient grounds for 

 supposing that bile is poured into the bowels, sometimes, in con- 

 siderable quantities; yet it does not appear that bile is taken into 

 the lacteals, or any of those almost aqueous fluids which exist in 

 the intestines, and are tinged with bile. If it be said that bile is 

 too thick a fluid to enter the orifices of the absorbents, the same 

 cannot be said of these aqueous fluids: nor, indeed, is the objec- 

 tion with respect to bile itself founded on analogy. To put this 

 discussion into a briefer form, 



3. Fluids existing in the intestines, and of a tenuity which 

 renders them capable of permeating the lacteals, are not taken up 

 by these vessels. Certain other fluids, constituting one of a pretty 

 uniform character, are taken up by the lacteals. The inference from 

 these facts is, that the lacteal orifices exercise a function of the 

 elective kind, by which some fluids are taken into them and others 

 rejected. 



4. The great proportion of watery liquors taken into the 

 stomach pass off by the kidneys or skin: as when a person drinks 

 two quarts per diem, and has a costive stool once in two or three 

 days. It matters but little how the qualities of these riquid ingesta 

 are varied; whether cyder, beer, lemonade, water, wine, tea, 

 coffee, gruel, or medicated drinks, or these mixed, they all enter 

 the lacteals to pass off by urine or sweat. From this fact we 

 should be disposed to infer that fluids pass from the intestines into 

 the lacteals merely according to hydraulic laws. But this in- 

 ference cannot be made positively, because the feet is liable to 

 another explanation; and we require some further facts to decide 

 whieh is true. A function of the above elective kind might be 

 exercised by thelacteal orifices on all these fluids; that is, they 

 may possess some properties in common with which tjiose of the 

 absorbents are related. 



