354 RETROGRADE ABSORBENTS. SECT. XXIX. a, 



tics, as mentioned by Mr. Hewfon, (Phil. Tranf, 

 v. 58.) 



6. Nor do all the inteftinal abforbents feem to 

 terminate in the thoracic ducr*, as appears from, 

 fome curious experiments of D. Munro, who gave 

 madder to fome ariirnals, having previoufly put a 

 ligature on the thoracic duel, and found their 

 bones, and the feruin of their blood, coloured red. 

 > , . i i ' ' ,. 



II* The Valves of the Akforbent Syftem may fujfcr tbeir 

 Fluids to regurgitate in fome Difeafes. 



i. THE many valves, which occur in the pro- 

 grefs of the lymphatic and lacteal veflels, would 

 feem infuperable o-bftacles to the regurgitation of 

 their contents. But as thefe valves are placed in 

 veflels, which are indued with life, and are them- 

 felves indued with life alfq ; and are very irritable 

 into thofe natural motions, which abforb, or propel 

 the fluids they contain ; it is poflible, in fame dif- 

 eafes, where thefe valves or veflels are ftimulated 

 into unnatural exertions, or are become paralytic, 

 that during the diaflole of the part of the yeflel to 

 which the valve is attached, the valve may not fo 

 completely clofe, as to prevent the relapfe of the 

 lymph or chyle. This is rendered more probable, 

 by the experiments of injecting mercury, or water, 

 pr fuet, or by blowing air down thefe veflels : all 

 which pafs the valves very eafily, contrary to the 

 natural courfe of their fluids, when the veflels are, 

 thus a little forcibly dilated, as mentioned by Dr. 

 Haller, Elem. Phyfiol. t. iii. f. 4. 



" The valves of the thoracic duel: are few, fome 

 afTert they are not more than twelve, and that they 

 do not very accurately perform their office, as they 

 do not clofe the whole area of the duel, and thencq 

 may permit chyle to repafs them downwards. In 

 living animals, however, though not always, yet 



morq 



