770 Experiments 



There was, therefore, a 15 cc. increase in volume. 



The digestive tube contained 60 cc. of gas, 45 cc. of which was 

 in the small intestine. At 3 atmospheres, the volume would be only 

 20 cc. So the 40 cc. decrease was filled about one third by the 

 diaphragm and two thirds by the abdominal wall. 



Experiment CCCXXX. June 28. Dog weighing 8.7 kilos, killed by 

 section of the medulla. 



The pulmonary capacity was 300 cc. 



After the pressure had been raised to 3 atmospheres, there were 

 750 cc. in the bag. 



According to the formula given above, the increase in the tho- 

 racic capacity was 50 cc. 



The compression was begun again and raised to 6 atmospheres. 

 At the decompression there were in the bag 2000 cc; the increase in 

 this case was 83 cc. 



There were in the alimentary canal 160 cc, which at 3 atmospheres 

 was reduced to 53 cc. (decrease of volume: 107 cc), and at 6 atmos- 

 pheres amounted to only 27 cc. (decrease: 133 cc). 



Experiment CCCXXXI. July 3. Dog weighing 8.4 kilos, killed the 

 day before. 



The pulmonary capacity was 369 cc. 



Compression made to 100 cm. of mercury (total pressure). The 

 bag then contained 157 cc. 



The real volume is derived from the proportion 100 : 76 = 

 (369 cm. + 157 = 526 cc.) : x = 399 cc; that is, an increase of 30 cc. 



Experiment CCCXXXII. July 13. Dog weighing 6.63 kilos. 

 The pulmonary capacity is 196 cc. 



Compression made to 3 atmospheres, then there was in the bag 

 512 cc. of air. 



The pulmonary capacity then was 236 cc; an increase of 40 cc. 



Experiment CCCXXXIII. July 26. Dog weighing 5.5 kilos, killed 

 by curare. 



Pulmonary capacity 232 cc. 



Taken to 3 atmospheres; the bag contained 627 cc; the capacity 

 then was 286 cc, an increase of 54 cc 



Taken to 6 atmospheres; the bag contained 1535 cc; therefore the 

 capacity was 294 cc, or an increase of 62 cc. 



So our anticipation was realized; the pulmonary capacity in- 

 creased in compressed air, by a simple physical effect, without any 

 active intervention of the respiratory muscles. But this increase 

 represented only a fraction of the decrease in volume of the in- 

 testinal gases. Furthermore, my experiments show that it is far 

 from increasing proportionally to the pressure; so in Experiment 

 CCCXXX, at 3 atmospheres it was 16% of the initial capacity, and 

 at 6 atmospheres only 26%; in Experiment CCCXXXIII, at 3 

 atmospheres, it was 23%, and at 6 atmospheres only 26%; even 



