Medicine. 23 1 



cording to him, the oxygen which disappears in 

 respiration combines with the blood in its passage 

 through the lungs, and at the moment of this com- 

 bination there is set loose from the blood a quan- 

 tity of carbonic acid gas and water, in the form of 

 vapour, which are thrown out with the air ex- 

 pired. This theory was adopted and illustrated 

 by M. Hassenfratz, who succeeded in proving 

 . its superiority to that of Lavoisier and his associ- 

 ates. The establishment of this theory depended 

 upon proving that the oxygenous portion of the 

 atmosphere alone is absorbed from the inspired air. 

 This w^as indeed the generally received opinion of 

 chemical philosophers for some time; but as it has 

 lately been brought into question, and the contrary 

 asserted, it is proper to notice the variation of 

 theory which has thence been attempted to be 

 made. 



Mr. Davy has endeavoured to prove that azote, 

 as well as oxygen, is partly absorbed by the lungs 

 in respiration. As the azote which disappears in 

 breathing is not to be found in the products of 

 respiration, it has been thence concluded that it 

 is absorbed by the blood. The experiments of 

 Mr. Davy led him to beUeve that atmospheric air 

 is absorbed by the blood in an undecomposed and 

 unaltered state; that it is afterwards decomposed 

 in that fluid by the affinity of the red particles for 

 its oxygen; that the greater part of the azote is 

 hberated without undergoing any change, and 

 again given out and mixed with the air in expira- 

 tion; but that a minute portion of it remains con- 

 densed in the serum and coagulable lymph, and 

 passes with them to the left ventricle of the heart. 

 A minute examination, and decision as to the cor- 

 rectness of these facts, will not be attempted in this 

 place. But admitting the facts to be justly stated, 

 the following changes will appear to be produccci 



