Gases of the Blood 591 



To study the influence of the number of respirations by isolating 

 it from that of the general movements of the body, which is always 

 involved, I poisoned the animals by curare, and when they were 

 completely paralyzed, I made use of artificial respiration by means 

 of a bellows introduced into the trachea. 



This bellows (Fig. 26) has an intake valve A, furnished with a 

 tube permitting any gas to be pumped into the lungs, and with a 

 graduated guide bar provided with a slide to control the move- 

 ments of the bellows. The variable position of the slide determines 

 the quantity of air injected. With this instrument, nothing is 

 easier than to measure exactly the amplitude and the number of 



Fig. 26 — Bellows for artificial respiration (A, pipe with valve which per- 

 mits the use of any gas). 



the artificial respirations. When the cannula has been introduced 

 into the trachea, which it does not quite fill, the little space left 

 between it and the walls is sufficient for the expiration to be made 

 easily; besides, in this respect conditions are always identical. 



I also used the apparatus construed according to the specifica- 

 tions of M. Grehant, which in my laboratory is operated by a small 

 water motor. 



Here is the result of an experiment, taken as an example. 



Experiment CLVII. February 19. Dog weighing 18 kilograms. 



At 4:05, lethal dose of curare subcutaneously; falls at 4:25; trachea 

 opened and artificial respiration carried on, the bellows delivering 

 350 cc. 



At 4:40, the artificial respiration is fixed at 16 per minute; the 

 pulse is 90. At 4:50, 72 cc. of blood taken from the femoral 

 artery ... A 



