8 COMPENDIUM OF THE VETERINARY ART. 



Of the Heart 



The heart is placed nearly in the middle of 

 the thorax : it is rather conical in its form ; the 

 apex inclining towards the left side; its base 

 attached to the bones of the back and ribs : 

 it is loosely invested with a membrane or sac, 

 termed pericardiuniy vulg^iYly heart- bag. This 

 sac always contains a small quantity of fluid, 

 which serves to lubricate its internal surface, 

 as well as the surface of the heart, to prevent 

 their cohesion, and suffer them to move freely 

 upon each other. Sometimes this fluid accu- 

 mulates, from a diseased action of the vessels 

 which form it, to a considerable degree. This 

 kind of drops}^ generally accompanies that of 

 the chest. The heart is divided into two cavi- 

 ties, termed ventricles, each of them having a 

 small hollow appendage, which, from a slight 

 resemblance it bears to a doo-'s ear, is named 

 auricle. The blood-vessels proceed from 

 these cavities, the arteries from the ventricles, 

 the veins from the auricles ; the former serving 

 to carry the blood from the heart to every part 

 of the body, for the purposes of nourislnnent, 

 secretion of the various juices, and stimu- 

 lating the system to action, as well as for fiu*" 



