Gases of the Blood 585 



temperature of the living body, or about that. The only incon- 

 venience is that the froth is increased by this method; but, thanks 

 to the length of the communicating tube and the current of cold 

 water, this froth very rarely enters the pump; furthermore, one can 

 easily check this froth by the skillful use of the three-way cock; 

 but these are skillful tricks that cannot be described easily. 



Introducing in this way, as I ordinarily did, 33 cc. of blood, the 

 gases are extracted by three strokes of the pump on the average; 

 I have seen them all come at the first stroke, and in other cases, 

 after the third stroke which hardly brings two or three centimeters, 

 I succeeded in getting one or two more by continuing the operation; 

 but that is the exception. 



I fairly often introduced in advance into balloon D, not merely 

 a few drops of water, as I said above, but 30 or 40 cubic centimeters 

 of water, which, of course, I boiled, and from which I extracted all 

 the gases before introducing the blood. This procedure has the 

 advantage, by diluting the blood, of lessening its coagulability and 

 checking the froth which issues from it from persisting and stop- 

 ping up tube DR, as sometimes happens; but this froth is then 

 easier to remove by a stroke of the pump, and rises to the top of the 

 tube; that is why I advised giving the tube a very decided slant 

 from the cock on, so that the froth may fall back easily instead of 

 remaining in the angle of the tubes. 



I had made a certain number of experiments by this procedure, 

 and I had assured myself by the comparative method, that it has no 

 disadvantage from the standpoint of quality and quantity of gases 

 extracted, when I read with surprise in the Proceedings of the 

 Academy of Sciences 1 a memorandum from MM. Estor and Saint- 

 Pierre in which the presence of water is charged with causing 

 enormously important differences in the extractions. 



According to the experimenters of Montpellier, the mixture of 

 water with the blood would facilitate the extraction of the oxygen 

 so much that the average quantity of this gas would be increased 

 from 4 cc. to 6 cc. per 100 cc. of blood. If it were so, one should, in 

 the first place, always use this mixture, and secondly, never com- 

 pare with each other results obtained with or without water. 



Unfortunately, MM. Estor and Saint-Pierre, instead of making 

 themselves comparative analyses made simultaneously with the 

 same blood, preferred, following a method which seems to be fa- 

 miliar to them, to compare to each other analyses made on the 

 blood of different animals and in entirely different conditions. Just 

 one of the experiments reported in their memoir (Experiment 



