80 



bon, and secondly by directly combining with oxygen. As to the 

 portion of oxygen which has disappeared, and which is not accounted 

 for by the carbonic acid evolved, it may have combined partly with 

 another portion of carbon, to form a limited amount of carbonic 

 acid, which by the law of absorption is retained in the blood ; and 

 partly with hydrogen or some other oxidable constituent of the 

 blood, without yielding a gaseous product. 



These two experiments it will be observed point to exactly the 

 same conclusions, and together with a number of others, where the 

 mode of procedure was similar, and which were attended with similar 

 results, have satisfied the author as to the fallacy of Magnus's doc- 

 trine, " that the oxygen received during respiration into the blood 

 is kept there merely by the law of mechanical absorption, and enters 

 into no chemical combination with that liquid." Had this assertion 

 been well-founded, such a change as has been seen to occur, in the 

 composition of the air enclosed along with blood, saturated as the 

 blood already was with oxygen, could not have happened. 



After having ascertained that air underwent certain changes in 

 composition during its contact with blood, it next became an object 

 to discover by which of the constituents of the blood these changes 

 were induced. With this view the author successively subjected the 

 organic compounds of the blood separately to the action of air, by 

 a similar process to that adopted in the case of the blood itself. 



A certain quantity of fresh fibrin, moistened with water, was satu- 

 rated with oxygen, placed in a receiver along with eight volumes of 

 air, and kept during twenty-four hours at a temperature of from 

 20 to 25 cent. At the expiration of this time the gas on analysis 

 was found to have the following composition : 



"T"""-;, ,^'ltotal oxygen.. 17-98 



Carbonic acid 11-17 J 



Nitrogen 82-02 



100-00 



thus showing that fibrin takes up a certain quantity of oxygen, and 

 gives off a stated amount of carbon combined with oxygen in form 

 of carbonic acid gas. 



The next experiments were made upon albumen, but as that sub- 

 stance could not be obtained in a pure, and at the same time un- 



