ABSORPTION OF ALCOHOL, ETC. MESENTERIC GLANDS. 281 



other, so that there is no proper free extremity in any case. It is quite 

 certain that the lacteals never open by free orifices upon the surface 

 of the intestine, as was formerly imagined. And there seems good 

 reason to believe, that either by the cells asserted by Prof. Goodsir 

 to be developed within the free extremities of the villi, or by the epi- 

 thelial cells which cover their extremities ( 243), a 

 selection is made of those substances which are proper Fi g- 83. 



to be received into the special Absorbent system. 



495. It is particularly important to keep in view 

 the difference between the two modes, by which ali- 

 mentary substances are introduced into the system, 

 when we are treating those disordered states, in 

 which the digestive process is imperfectly performed, 

 or is altogether suspended. There can be little 

 doubt that the immediate cause of death, in many 

 diseases of exhaustion, is the want of power to main- 

 tain the heat of the body ; the stomach not being 



,. , , , ,Y . , . . o One of the Intestinal Vilh, 



able to digest food, and the special absorbent power with the commencement of 

 of the lacteals being altogether suspended, so that al 

 the inanition is as complete, as if food were altogether withheld. 

 Now under such circumstances, it becomes a matter of the greatest im- 

 portance to present a supply of combustible matter, in such a form that 

 it may be introduced into the circulating system by simple Endosmose ; 

 and the value which experience has assigned to broths and to thin fari- 

 naceous solutions, and still more, to diluted alcoholic drinks, frequently 

 repeated, under such circumstances, seems to depend in great part upon 

 the facility with which they may be thus absorbed. The good effects 

 of alcohol, cautiously administered, are no doubt owing in part to its 

 specific influence upon the nervous system ; but that they are also due 

 to its heat-producing power, appears from the results of the administra- 

 tion of frequently-repeated doses, in states of utter exhaustion, the 

 temperature of the body being kept up so long as they are continued, 

 and falling when they are intermitted ( 118). As the alcohol is thus 

 burned off nearly as fast as it is introduced, it never accumulates in 

 sufficient quantity, to produce its usual violently-stimulating effects upon 

 the nervous system. 



2. Passage of the Chyle along ike Lacteals, and its admixture with the Lymph 

 collected from the general System. 



496. The Lacteal vessels, which commence on the surface of the in- 

 testines, run together on their walls, and form larger trunks, which 

 converge and unite with each other in the mesentery ; and the main 

 trunks thus formed then enter certain bodies, which are commonly 

 known as the "mesenteric glands." Their structure, however, does not 

 seem to correspond with that of the proper glands ; as they are simply 

 composed of lacteal trunks, convoluted into knots, and dilated into 

 larger cavities, amongst which blood-vessels are minutely distributed. 

 These blood-vessels have no direct communication with the interior of 

 the lacteals ; but are separated from them by the membranous walls of 



