122 



DE RUTHERFORD ON THE INFLUENCE OF THE VAGUS. 



EXPERIMENT XXIII. — Old Spaniel Dog. Canula in Carotid Artery. Trachea open. 



Time. 



Pulse in 15". 



Mean Pressure in inches 

 ofHg. 



General Notes. 



4.28' 



25 



51 





30" 







2 milligrammes atropiae sulph. in- 

 jected into vein. 



29' 



46 



71 





34' 







Clot in canula. Apparatus cleaned. 



42' 



42 



4-9 





43' 



38 



43 



Hitherto the respiration has heen 

 rapid and irregular. 



48' 



40 



4-7 



Animal sobhing. 



49' 







20 minims Tincture Opii given. 



30" 



40 



61 





52' 







Clot in canrda. Apparatus cleaned. 



54' 



33 



4-6 





55' 







0*13 milligramme atropine sulph. 

 given. 



56' 30" 



34 



4-6 





59' 







Left vagus divided. 



5 o'clock. 







Clot. Apparatus cleaned. 



3' 30" 



— 1 



4-9 





4' 







Eight vagus divided. 



5' 30" 



41 



51 





6' 30" 



40 



5-61 





9' 



43 



52 





12' 



44 



5-4 





13' 







Cardio-inhibitory nerves found to | 

 be completely paralysed. 



These experiments show that in dogs division of the vagi in the neck may 

 be followed by accelerated cardiac action and increased blood-pressure, although 

 the cardio-inhibitory nerves be paralysed. It is clear, therefore, that physiolo- 

 gists generally are mistaken in supposing that the acceleration of the pulse 

 which commonly follows division of the vagi, is entirely due to the heart's being 

 liberated from its controlling nerves. A portion — perhaps, in some cases, the 

 whole — of that acceleration may be due to division of other filaments than those 

 which retard the heart's action. I shall not, at present, enter into a discussion 

 of the causes of the increased blood-pressure observed in these experiments. 

 The reason for this will be readily perceived when my remarks upon other 

 experiments performed on dogs have been perused. (See page 137.) 



The consideration of these changes which follow division of the vagi will be 

 resumed after we have inquired into the present state of our knowledge regard- 

 ing the 



Innervation of Blood-Vessels. 

 By the investigations of Bernard and Brown-Sequard, it has been estab- 



