On Respiration. 41 9 



The quantity of azote added, of oxygen missing, and of 

 carbonic acid formed, were smaller than in the last experi- 

 ment; but the animal in this instance was smaller, as well 

 'as the quantity of oxvgen passed through in a given time. 



In this case, as in the human subject, the increase of 

 azote takes place principally in the early periods. The 

 whole azote contained in the 66 cubic inches, confined 

 with the pig, was only 52" 14; but supposing, which per- 

 haps was not the case, that the 66 of common air were 

 expelled by the first 250 cubic inches of oxygen, we 

 should have 250 

 Jess 66 



184 of oxygen, 

 containing 5 per cent, azote, or 9*20 cubic inches : these 

 added to the .52- 14, would make Gl"34 of azote to be found 

 in the first gasometer of respired gas, but we detected 75, 

 so that even on this supposition 13"66 of azote were added 

 in the first twenty-four minutes. 



The azote contained in the second gasometer before re- 

 spiration, was 12*50 cubic inches, but aflcr it had been 

 respired for twenty-three minutes, we found 23-75, or aa 

 increase of 11 '25 azote. The azote contained in the third 

 gasometer, before respiration, was, as before, 12*50 cubic 

 inches; but after it had been respired for twenty-four 

 minutes, wc found 20, or an increase of 7*50 azote. 



The azote contained in the 66 cubic inches was 3*39, 

 but we found 5*28, or an incttase of 1*98 azote. 



From the results of these experimenis, it seemed that 

 when the usual proportion of azote was not present in the 

 gas respired, there was a disposition in the blood to give 

 out a certain quantity in exchange for an equal volume of 

 oxygen, and we resolved to trv, whether this circumstance 

 would occur when hydrogen was substituted fur azote ; we 

 accordingly made a mixture containing 22 percent, oxygen 

 and 78 hydrogen. 



Expcrhntnt 6. Hydrogen a?id Oxygen, 



The pig employed in the last experiment was placed 

 upon the stand in the glass A, with 66 cubic inches of 

 commf)n air as usual. 



250 cubic inches of the; mixture were passed from the 

 gasometer communicaiine; with B, through the glass A into 

 the gasometer conuiiunicating with C, during sixteen mi- 

 nutes. The animal did not appear uneasy : a second quan- 

 tity of 230 cubic ijachcs was passed in seveuteen minutes 

 D d 2 anal 



