RETENTION OF INHIBITORY ACTION BY VAGUS. 213 



into the jugular vein, A cannula was then put into the trachea, 

 and a thread passed under the right vagus. The temperature 

 in the rectum was 04'8'^ F. Hot water was then poured into 

 the apparatus ; an india-rubber bottle containing hot water was 

 placed on the belly, and the cannula in the trachea was con- 

 nected with a flask containing warm water, so that the inspired 

 air should be warm and moist. The temperature gradually 

 rose, and the power of the vagus over the heart was tested by 

 irritating it from time to time. 



Temp. 105*2° F. Irritation of vagus stops the heart. 



106 „ „ acts, but not so strongly. 



109*2 „ „ causes slowing, but no stoppage. 



-'-•'-5 »> » » }> >> » 



The pulse became slow and weak, and the animal was removed 

 ond 23ut under a tap of cold water, but its pulsations were not 

 restored. On post-mortem examination the venous system was 

 found much congested. 



Experiment II. — A rabbit, weighing about 3 J lbs., was narco- 

 tised by injecting a solution of chloral subcutaneously. An 

 hour and a half after it was put in the apparatus, a cannula put 

 in the trachea^ and a thread passed under the right vagus ; but 

 the nerve was not cut. Temperature in rectum 100"2° F. Hot 

 water was poured into the apparatus, and the inspired air passed 

 over hot water. The temperature sank to 100° F. ; it then 

 began to rise, but the animal died before it rose much above 

 104° F. 



Experiment III. — A young rabbit, weighing about 3 lbs., was 

 narcotised by the subcutaneous injection of about 30 grs. of 

 chloral. It was fastened in the apparatus ; a fine needle was 

 thrust into the heart, and connected with one of Marey's cardo- 

 graphic levers. The needle was removed at the end of each 

 tracing. Cannula in trachea. 



Temp. Pulse in 15". 

 85 



Right vagus irritated , 6 



85 



103 -6° F 85 



Eight vagus irritated 5 



82 

 105-4 85 



