8o 



Scientific Proceedings (64). 



order to test the theory of possible transmission of centripetal 

 impulses from the periphery to the central nervous system during 

 full anesthesia certain means as noted below were used over pro- 

 longed periods. The details of these experiments I shall leave 

 to Dr. Jackson and Dr. Janeway to describe. 



In all twenty- two dogs were used. The experiments may be 

 divided into five series, as follows: 



Series 1. — Vena cava occlusion and stimulation of both sciatics. 

 Series 2. — Hemorrhage. 

 Series 3. — Handling intestines. 



Series 4. — Transection of mid-brain anterior to the corpora quadri- 



gemina and handling of intestines. 

 Series 5. — Transection of mid-brain and stimulation of sciatics. 



In series 1 there were thirteen dogs; in series 2 there were four 

 dogs; in series 3 there were two dogs; in series 4 there were two 

 dogs and in series 5 there was one dog. 



In the thirteen dogs of series 1 the blood-pressure averaged 

 during the experiment from 34 to 52 mm. The lowest pressure 

 recorded was 20 mm. which was noted in three cases; the highest 

 pressure recorded during these experiments was 70 mm. which was 

 noted in three cases. Eight of the animals in series I were killed 

 immediately at the end of the experiment. Two animals were 

 killed six hours after the experiment. One animal was killed five 

 and one half hours after the experiment and two were killed twenty 

 hours after. 



In the four dogs of series 2 the average blood-pressure recorded 

 during the experiment was from 34 mm. to 54 mm. The lowest 

 pressure was 20 mm. and the highest 70 mm. All the animals of 

 this series were killed at the conclusion of the experiment. 



In the two dogs of series 3 the blood-pressures were in one 150 

 mm. at the beginning of the experiment and 60 mm. at the end; 

 in the other animal the pressure was 130 mm. at the beginning and 

 90 mm. at the end. Both dogs were killed at the end of the 

 experiment. 



In the two dogs of series 4 the blood-pressure was 80 mm. at 

 the beginning and 30 mm. at the end in one; and 80 mm. at the 

 beginning and 70 mm. at the end in the other. Both animals were 

 killed at the termination of the experiment. 



