636 



Experiments 



there appears once more the proof that decompression acts as a 

 simple asphyxiating agent. 



When this truth had been established, it became possible for 

 me to find out how the gases of the venous blood vary during de- 

 compression. I had tried repeatedly to extract the venous blood 

 of a dog placed in my large cylinders; difficulties which all experi- 

 menters will divine had prevented me from succeeding; clots 

 formed in the cannulas, air bubbles, which the pressure of the 

 blood no longer opposed, rushed into the right heart, etc. 



But respiration in an air whose oxygen content was gradually 

 lessened allowed me to avoid these difficulties. And so I did in the 

 following experiments. 



Experiment CXC. July 30. Dog weighing 12 kilos. Muzzle hermeti- 

 cally closed. 



2:05; Forced to breathe with the potash valves from a bag con- 

 taining 90 liters of air. 



2:10; respirations, 26; pulse, 100. Drew from the carotid 25 cc. 

 of blood, not very red .... A 



2:20; Drew from the left jugular, peripheral end, 25 cc. of blood, 

 rather dark .... A' 



The animal, whose eyes are covered, remains perfectly quiet. 



3:07; 22 respirations; pulse, 100. 



3:10; Drew 25 cc. of blood from the carotid, almost as red as 

 A .... B 



3:15; Took sample of air from the bag . . . . b 



3:20; Drew 25 cc. of venous blood . . . . B' 



4: 10; Drew 25 cc. of arterial blood, dark . . . . C 



4:15; Took air from the bag . . . . c 



The animal suddenly makes a violent effort and pulls off the 

 rubber bag for an instant (takes one inspiration of outer air) ; con- 

 tinued efforts and considerable panting. 



4:22; 25 cc. of very dark venous blood . . . . C 



4:30; pulse, 60; 18 deep respirations. 



4:38; dies; a few very weak heart beats. Drew arterial blood, 

 very dark . . . . D 



Took air from the bag . . . . d 



Summary of the Experiment 



