652 ABSORPTION. 



subclavian exerts considerable effect on the progress of the chyle. We 

 have reason to believe that its course is slow. It has been already 

 stated, that in an experiment on a dog, which had eaten animal food at 

 discretion, M. Magendie 1 found half an ounce of chyle discharged from 

 an opening in the thoracic duct in five minutes. Still, as he judiciously 

 remarks, the velocity will be partly dependent upon the quantity of 

 chyle formed. If much enters the thoracic duct, it will probably pro- 

 ceed faster than under opposite circumstances. In the commencement 

 of the thoracic duct it becomes mixed with lymph; and under the head 

 of lymphatic absorption we shall show how they proceed together into 

 the subclavian, and the effect produced by the circumstances under 

 which the thoracic duct opens into that venous trunk. 



It has been a subject of inquiry, whether chyle varies materially in 

 different parts of its course ; and what is the precise modification, 

 impressed upon it by the action of the mesenteric glands. The experi- 

 ments of Reuss, Emmert, 3 and others, seem to show, that when taken 

 from the intestinal side of the glands it is of a yellowish- white colour; 

 does not become red on exposure to the air, and coagulates but imper- 

 fectly, depositing only a small, yellowish pellicle. It is said, indeed, 

 that chyle, drawn from the chyliferous vessels, which traverse the intes- 

 tinal walls, contains albumen in a state of solution, but no fibrin, and 

 abounds in oleaginous matter ; whilst that from the other side of the 

 glands, and near the thoracic duct, is of a reddish hue : contains chyle 

 globules, coagulates entirely, and separates into a clot and serum. M. 

 Vauquelin, 3 too, affirms, that it acquires a rosy tint as it advances in 

 the apparatus ; and that the fibrin becomes gradually more abundant. 

 These circumstances have given rise to the belief, that as it proceeds 

 it becomes more and more animalized, or transformed into the nature 

 of the being. This effect has generally been ascribed to the mesenteric 

 glands ; and it has been presumed by some to be produced by the exha- 

 lation of a fluid into their cells from the numerous bloodvessels with 

 which they are furnished. Others, again, consider, that the veins of 

 the glands remove from the chyle every thing that is noxious ; or purify 

 it. From the circumstance, that the rosy colour is more marked on 

 the thoracic, than on the intestinal side of the glands ; that the fluid 

 is richer in fibrin after having passed through those glands ; and that 

 the rosy colour and fibrin are less when the animal has taken a large 

 proportion of food, MM. Tiedemann and Gmelin 4 infer, that it is to the 

 action of the glands, that the chyle owes those important changes in its 

 nature; the fluid, in its passage through them, obtaining, from the 

 blood circulating in them, new elements, which animalize it. 



There is much probability in the view, that some nitrogenized mate- 

 rial is secreted from the lining membrane of the chyliferous vessels, in 

 the mesenteric glands especially, through the agency of the nucleated 

 cells described by Professor Goodsir, which may be a great agent in 

 the changes effected on the chyle in its course. At the same time as 



1 Precis, &c., ii. 183. 



2 Reil's Archiv., viii. s. 2; and Annales de Chimie, Ixxx. 81. 



3 Annales de Chimie, Ixxxi. 113 ; and Annals of Philosophy, ii. 220. 



4 Die Verdauung nach Versuchen, u. s. w.,or Jourdau's translat., Paris, 1827. 



