Action of Carbonic Acid 913 



The next day we find that the whole bodies furnished, if pro- 

 portioned to 100 gm.: 



A (killed by carbonic acid) 33 cc. of CO : 



B (killed by carbonic acid) 36 cc. of CO. 



C (died of asphyxia, at normal pressure) 17 cc. of CO. 



D (died of simple lack of oyxgen, at Mj atmosphere __0 cc. of CO. 



We now understand the phenomenon in its entirety and its 

 simplicity. When an animal breathes in a confined medium in 

 which it will not lack oxygen, the increasing tension of the carbonic 

 acid which it excretes maintains in its arterial blood a proportion 

 of this same gas, which also increases. Since a similar equilibrium 

 is established between the blood and the tissues, in which the true 

 source of the carbonic acid exists, this gas is gradually stored up 

 in the whole organism. From this fact arise general disturbances, 

 the symptoms of which we shall presently discuss in detail. 



Under these conditions, the blood is finally burdened with an 

 enormous quantity of carbonic acid; we have found as high as 

 116.6 volumes of it per 100 volumes of arterial blood and 120.4 per 

 100 volumes of venous blood. This last proportion is approaching 

 saturation. This saturation, which must vary from one blood to 

 another, is, in fact, approximately determined by the following 

 experiments, rather rough no doubt, but which can give us a gen- 

 eral idea sufficient for our purpose. 



Experiment DCXXIX. February 22. Temperature of the laboratory 

 14°. Defibrinated dog blood. 



I place 100 cc. of it in two test tubes inverted over mercury, and 

 then add to each one 200 cc. of carbonic acid. Energetic repeated 

 shaking; immediate and considerable absorption; much foam. Left 

 the two test tubes in the ambient temperature. 



The next day, shaken again. 3 hours afterwards, made the anal- 

 ysis by means of the gas pump. 



The extraction and analysis give the following results (gaseous 

 volumes reduced as usual to 0°): 



One of the bloods contained CO, 123 cc; O, 16.6. 



The other blood contained CO, 132 cc; O, 11.0. 



Experiment DCXXX. March 10. Defibrinated dog blood. Temper- 

 ature of the laboratory 15°. Pressure 764 mm. 



100 cc. are placed at the bottom of two flasks, through which 

 passes a current of carbonic acid for 24 hours. One of the flasks is 

 immersed in water at 41°. 



We find thus that 



The blood at 15° contains 177.6 cc of CO,. 



The blood at 40° contains 138.4 cc. of CO ; . 



