Gases of the Blood 651 



By working the pump and holding the balloon containing the 

 blood above the horizon, the blood is made to pass into the barometric 

 chamber and then into a syringe. In this way 69 cc. are obtained 

 which are introduced into the second mercury pump. The extraction 

 of the gases gives 14.5 cc. of oxygen; that is, per 100 volumes and 

 after corrections, 19.8, exactly like the preceding. 



So the blood absorbs exactly the same quantity of oxygen in both 

 cases. 



Experiment CCIII. December 31. 



100 cc. of dog blood absorbed at the ordinary pressure of 760 mm. 

 32.4 cc. of oxygen. 100 cc. of the same blood, first deprived entirely of 

 gas, absorbed under the pressure of 24 mm., that is, at a pressure 32 

 times less, 26.1 cc. of oxygen. 



Experiment CCIV. March 20 and 21. From a branch of the femoral 

 artery of a terrier in good health 500 gm. of blood were taken and 

 defibrinated by agitation in a flask. 



In a large flask whose interior volume is equal to 4.335 liters, a 

 vacuum is made by means of the pneumatic machine; next, the air 

 is extracted by a mercury pump so as to bring the pressure of the 

 remaining air to about 2 centimeters; 68 cc. of blood completely freed 

 of gas by means of a mercury pump at 40° are injected into the flask 

 by means of a syringe, and the blood is shaken with the rarefied air 

 for a half hour by the hydraulic motor. After the agitation, the 

 pressure of the rarefied atmosphere is measured and the ascertained 

 pressure of the water vapor tension at the temperature of the labora- 

 tory air is deducted, so as to obtain the pressure of the air assumed 

 to be dry; it is only 152 mm. The gases are extracted from the blood 

 agitated with the air under this low pressure by passing the blood 

 directly from the flask into an evacuated gas pump (the flask being 

 weighed before and after). 



2.) By means of a syringe, 68 cc. of blood freed of gas and 68 cc. 



of air are injected into the flask; agitation for a half hour, etc 



In the following experiments, each time in the same way, 68 cc. of 

 blood and 68 cc. of air are injected. Here are the results obtained 

 after the necessary corrections: 



100 gm. of blood first freed of gases 

 At the pressure of 15 cm. absorbed 7.3 cc. of oxygen. 

 At the pressure of 29 cm. absorbed 9.9 cc. of oxygen. 

 At the pressure of 40 cm. absorbed 12.3 cc. of oxygen 

 At the pressure of 51 cm. absorbed 13.2 cc. of oxygen. 

 At the pressure of 75.6 cm. absorbed 18.5 cc. of oxygen. 



We conclude then from these data that down to low pressures 

 the contradiction noted between experiments made in vitro on the 

 capacity of blood for oxygen and the analyses of the blood of living 

 animals exists entirely as it appeared to us at first. At all pressures, 

 the blood, agitated in a flask, contains an almost equal quantity of 

 oxygen (graph A of Fig. 43) , whereas in the living animal the pro- 



