SECT. II. i. DEFINITIONS. 9 



foii.-e fluid, as faliva, tears, perfpiratlon, are fepa- 

 rated from the blood ; and the remainder of the 

 blood is abfoibed or drank up by branches of veins 

 CTrefpondent to the branches of the artery ; which 

 are fu mimed with valves to prevent its return ; and 

 is thus carried back, after having again changed its 

 colour to a dark red, to the right chamber of the 

 heart, The circulation of the blood in the liver 

 differs from this general fyftem ; for the veins which 

 drink up the refluent blood from thole arteries, 

 which are fpread on the bowels and mefentery, unite 

 into a trunk in the liver, and form a kind of artery, 

 which is branched into the whole fuhltance of the 

 liver, and is cahed the vena portarum ; and from 

 which the bile is feparated by the numerous hepatic 

 glands, which constitute that vifcus. 



7. The glands may be divided into three fyftems, 

 the convoluted glands, fuch as thofe above defcribed, 

 which feparate bile, tears, faliva, &c. Secondly, 

 the glands without convolution, as the capillary vef- 

 fels, which unite the terminations of the arteries and 

 veins ; and feparate. both the mucus, which lubri- 

 cates the cellular membrane, and the perfpirable 

 matter, which preferves the Ikin moift and flexible. 

 And thirdly, the whole abforbent fyftem, confining 

 of the lacleals, which open their mouths into the 

 ftomach and inteflines, and of the lymphatics, which 

 open their mouths on the external furface of the 

 body> and on the internal linings of all the ceils of the 

 cellular membrane, and other cavities of the body. 



Thefe lacteal and lymphatic veflels are furnifhf d 

 with numerous valves to prevent the return of the 

 fluids, which they abforb, and terminate in glands, 

 called lymphatic glands, and may hence be confi- 

 dered as long necks or mouths belonging to thefe 

 glands. To thefe they convey the chyle and mucus, 

 with a part of the perfpirable matter, and atmof- 

 pherk moifture ; all which, after having pafled 



through 



