654 



Experiments 



gas in simple solution would do. But in the living organism, this 

 is complicated by an insufficient agitation of the blood in contact 

 with the air, and so there results a much more rapid decrease of 



the oxygen of the blood than ex- 

 periments in vitro would lead one 

 to think. 



2. Increased Pressure. 

 To study the absorption of oxy- 

 gen by the blood at pressures 

 greater than one atmosphere, I had 

 made a bronze receiver, of a ca- 

 pacity of 175 cc, capable of resist- 

 ing 25 atmospheres easily. (Fig. 

 45.) The procedure was very 

 simple. In the apparatus, whose 

 lower part could be unscrewed, 

 was placed the defibrinated blood 

 to be analyzed; I used about 100 

 cc. of it. Then, after the cylinder 

 had been closed, I compressed the 

 air by screwing on the compres- 

 sion pump, and closed cock R when 

 the manometer indicated that the 

 desired pressure had been reached. 

 I next agitated the apparatus by 

 fastening it on the plank of Fig- 

 ure 42. Finally, to extract the blood 

 into the graduated syringe, I had 

 only to fit its extremity to the 

 capillary cock r, which I half- 

 opened; the air pressure immedi- 

 ately drove the blood out; a few 

 strokes of the pump kept a con- 

 stant pressure in the apparatus 

 while the blood was being taken 

 out. When I was dealing with 

 very high pressures, when nitro- 

 gen dissolved in quantity was 

 given off in the syringe, I substi- 

 tuted weight for volumetric mea- 

 sure, since the froth did not per- 

 mit me to determine volume 

 exactly. 



When I wished to make an analysis 

 at a certain compression, I began by supersaturating the blood by 



Fig. 45 — Apparatus to saturate 

 blood with air at high pres- 

 sures. R. Large cock by which 

 compression is made. r. Capil- 

 lary cock by which blood sam- 

 ples are taken. 



