652 Experiments 



portion of oxygen diminishes rapidly, as is shown by graph C, 

 which reproduces graph Ox of Figure 31, and the analyses sum- 

 marized in Table X. 



Considering this difficulty, I asked myself whether the high tem- 

 perature of the animal's body could not cause some changes in the 

 results I obtained at low temperatures. We knew already that to 

 extract the oxygen of the blood completely we must add to the 

 action of the vacuum that of a rather high temperature. I will 

 report here an experiment which demonstrates this truth. 



Experiment CCV. June 24. 65 cc. of defibrinated dog blood are 

 placed at 4 o'clock in the receiver of a pump for the extraction of 

 gases, in which an absolute vacuum had previously been made. The 

 temperature is only 19°. 



The blood is shaken repeatedly in the balloon and all the gas 

 which will come out is extracted, but without warming it. We obtain 

 thus, per 100 cc. of liquid, 11.2 cc. of oxygen, 20.0 cc. of carbonic acid, 

 and 2.0 cc. of nitrogen. 



This procedure is repeated until 6 o'clock; no more gas has come 

 after several pump strokes, and the blood has remained bright red. 

 The double-boiler is heated to the boiling point, and then, with a 

 single pump stroke, the rest of the gas is extracted; the blood turns 

 dark immediately. The quantity just extracted represents, per 100 cc. 

 of blood: Oxygen 13.2; CO 13.0; N 0.6. 



So the blood contained in all: O* 24.4 cc; CO 33.0; N 2.6. 



If this blood had been subjected to the experiments performed 

 by the method previously described, and if a complete vacuum had 

 been made in the agitation flask, at 19°, 13.2 cc. of oxygen could 

 have still been extracted by the heat. Temperature has, therefore, 

 a great importance. 



And so I set up the experiment in a slightly different manner. 

 The agitation flask, instead of being fastened on the plank of 

 Figure 42, was solidly fastened underneath at a certain distance, so 

 as to dip into a bath of lukewarm water whose temperature was 

 kept at a fairly constant degree all through the agitation. 



Here are the results of experiments made under these conditions. 



Experiment CCV I. June 3. Dog blood; shaken for x k hour, the 

 flask of 4.330 liters being submerged in water at 40°. 



At 725 mm. (deduction of water vapor tension) it contains: O s 15.4 

 At 280 mm.: 2 13.8. 

 At 100 mm.: O a 8.5. 



Experiment CCVII. July 10. Dog blood; shaken for 20 minutes, the 

 flask of 4.330 liters being submerged in water at 40°. 



At 738 mm. (with the usual deduction), the blood contains: 

 Q 2 20.1; CO, 18.8; N 1.5. 



