THE GIECULATION. 



737 



that this large amount of blood in the body makes its entire 



round of circulation in the short period of from two to three 



minutes. This has 



been proved by the 



following experiment, 



which has been made 



and repeated many 



times at the Colum- 



bia Veterinary Col- 



lege, New York: The 



jugular vein was 



opened on one side of 



the neck, into which 



saline matter, or poi- 



son, was injected, and 



on opposite side tap- 



ped carotid artery. 



In fifteen seconds the 



first traces of the sub- 



stance injected could 



be detected in the 



blood; in twenty sec- 



onds it was found 



very plainly. But 



while it is known 



that the main body of 



blood makes the 



shorter pulmonary 



Circuit, that part go- 





 ing to the extremities terior 



FIG. 627. The heart and principal vessels: 

 right face. 



" Right ventricle ; b ' Left ventricle; e. Right an- 

 ricle ; a. Anterior vena cava ; e. Vena azygos ; /. Pos- 

 vena cava . g ^ g Pulmonary veins . ^ h . D ivis- 



most distant from the ions of the pulmonary artery; i. Posterior aorta; j. 

 heart requires much Anterior aorta; k. Thoracic duct; I. Right cardiac ar- 



lono-er time; but it is tery; m ' Its vertical or ventricular branch ; - Ven- 



tricular branch of the cardiac vein ; p. Auriculo-ven- 



assumed that all the tricular branch of the same> 



blood in the body 



makes its entire circuit in the short period of from two to three 



minutes. 



I refer to this fact, which is not familiar to the average reader, 

 to show the great importance of not subjecting the horse to such 



47 



