CuApAllT/oeAnatopij^ofaUOKSE. 25 



^11. Of the Heart and Pericardium, ^c. 



The Pericardium is that Bag in which TJ^e Pericardi- 

 the Heart is inclofed, as in a Purfe. It riles ^^y ^ ^^^/^ ^J 

 from the Bafis, or upper Part of the Heart, ^"' ^^^'■^- _ 

 from the outer Coats of the great Veffels, which fpring 

 originally from the Pleura. It is of a middle Subftancc, 

 neither very hard, fo as to hurt the Lungs, nor yet io 

 foft as to be itfelf eafily injured by the Pvlotion of the Heart. 

 It is perforated in five Places, namely ^ on the right Side, 

 for the afcending Trunk of the Cava^ which coming from 

 the Liver, enters the right Ventricle^ and by the Suh- 

 dav'ian Vein, which defcends by the Channel-bones into 

 the fame Ventricle ; and thirdly, by the Pulmonary Artery, 

 which goes out of the right Ventricle into the Lungs : On 

 its left Side it is perforated for a Pailage to the Pulmonary 

 Vein, which comes from the Lungs, and enters the left 

 A'cntricle : And, lallly, for the great Artery- that paiTes out 

 of the fa id Ventricle. 



Its Veins are from the Phrenick and .^«x//- Its Vejfds. 

 liarics ; its x^rteriesare fo fmall, that they are 

 not very difcernable ; its Nerves come from the Parvagum* 



Tlie Ufe of this Purfe or Bag, is to cover j^^ jj^^ 

 the Heart, and be a Defence to it, to contain 

 a Moifture not only to keep it glib and e?Jy in its Motion, 

 but alfo cool. There are various Opinions concerning 

 this Liquor of the Pericardium^ and from whence it is de- 

 rived ; but I fhall not give the Reader any Trouble by re- 

 citing them, but haften to the Heart itfelf. 



The Heart is the principal Fountain The Heart. 

 which fends Blood and Nourifliment into 

 all Parts of the Body, and is wonderfully fuited in every 

 Refped for that Purpofe. 



It is fituated in the Midft of the Cheft, where it is en- 

 compaficd by the Lobes of the Lungs, having its Point in- 

 clining to the left Side. It is in Shape not very different 

 from what it is in moft other Animals, only in a Horfe it 

 does not grow gradually narrow towards its Point, as in 

 Ibme, nor {0 broad in Proportion at its Balis or Root. 



Its Subllance is fiefhy and very folid, that j^^ Suhflance. 

 it m.ay the better endure the Perpetuity of 

 Motion, and expel the Blood with more Force tcf all Parts of 

 the Body. It is for that Purpofe compofed Cf mufcular and 



iielhy 



