THE CIECULATION. 



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 

 j u g u 1 a r 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 twentv 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 

 most distant from the 

 heart requires much 



Fig. 627. 



-The heart aud priucipal vessels: 

 right face. 



a. Right ventricle; b. Left ventricle; c. Right au- 

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

 terior vena cava; (/,(/. Pulmonary veins ; /t, h. Divis- 

 ions of the pulmonary artery; i. Posterior aorta; j. 

 Anterior aorta; Jc. Thoracic duct; 1. Right cardiac ar- 

 lonfi'er time • but it is ^^^•' ' "*' ^*^ vertical or ventricular branch ; o. Ven- 

 T ., , ,, ,, 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 



