Dr. Harley on the Oxygen absorbed into the Blood. 479 



and kept during twenty-four hours in a room of moderate tem- 

 perature. In order to favour the mutual action of the air and blood, 

 the vessel was frequently agitated. At the expiration of twenty-four 

 hours the gas was analysed by Bunsen's method. In an example 

 cited the follovnng was found to be its composition : — 



Oxygen 10*42 1 , ^ . .. .^ 



Carbonicacid .... ^.o^]tot^^o^jgm:=.\b'A7 



Nitrogen 84*53 



100-00 



On comparing this with the composition of the common air 

 (oxygen 20*96 ; carbonic acid 00*002 ; nitrogen 79*038) which had 

 been introduced into the vessel, it is seen that 10*54 per cent, of 

 oxygen has disappeared, while 5*05 per cent, of carbonic acid now 

 exists, where only a trace of its presence could before be detected. 



Similar results were obtained with defibrinated blood. In a case 

 where defibrinated arterial blood from a calf, after complete satura- 

 tion with oxygen, was kept in contact with an equal volume of air 

 during twenty-four hours, and treated exactly as in the previous ex- 

 ample, the gas on analysis yielded in 1 00 parts, — 



£Ee-a<:id:::.":96}*''''^°wn=ir29 



Nitrogen $2*71 



100*00 



showing in this case also that the air which had been imprisoned 

 during twenty-four hours along with blood, no longer possessed its 

 original composition, but that some of its constituents had been 

 materially increased, while others had diminished in a manner no less 

 marked. 



It would appear from these examples that the blood had probably 

 become oxidized in two ways ; first, by giving off a quantity of car- 

 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 



