66 The Art of Fa r r i e r y 



PreflTure, and thereby eafe the Heart; fo that its 

 Syftole or Contraftion need not be fo ftrong in 

 order to drive the Blood round the Body, as would, 

 without thefe Valves, have been neceffary ; I fay, 

 kt any one confider even this fmalleft Piece of the 

 Creator's Architedlure in Brutes as well as Human 

 Bodies, and then tell me whether we are not (as the 

 Ffalmift fays) wonderfully formed. 



No lefs furprizing is God's Handy-work in creat- 

 ing Animals in fuch Manner, as that the Blood in 

 the Fena ca<va defcendens fhould not prefs upon and 

 hinder that in the Vena cava afcendens from enter- 

 ing the right Auricle or Ear of the Heart ; and in 

 crder to take ofF this Hindrance, there is a fmrtU 

 Protubrance juft where the afcending and defcending 

 Trunks of the Ca^va join, which not only hinders 

 the defcending Blood from preffing the afcending, 

 but, moreover, diverts both into the Auricle. Now 

 in this Cafe, a Valve would not have done the 

 BuHnefsj for there would then have been fome, 

 though lefs perpendicular, Preilure from the de- 

 fcending upon the afcending Blood in the Caia ; 

 But by this Contrivance, the defcending Blood from 

 the Parts above the Heart, does not in the leall in- 

 commode the Pafiage of that below the Heart, but 

 is fupported by the Protuberance mentioned ; in the 

 fame Manner as a long Stone put into a Wall to 

 fupport a Weight above it ; as is common among 

 Builders to perform, when they would have the 

 Work projea or jut out beyond the naked Face of 

 the Wall, Pedeftal, ^c. 



As I have faid in the Clofe of my Difcourfe up- 

 on the Arteries, fo I fhall fay with relation to the 

 Veins, fviz. that I now forbear a particular De- 

 fcription of them ; but fhall mention the moft con* 

 fiderable Branches, as they occur to me, when I 

 treat of the Diftempers incident to Horfes. 



Thirdly^ I fhall fhew what is meant by an Ani- 

 inal Fibre ; by reafon fuch Knowledge is abfolutely 



needful 



