On Respiratio-Ji. 383 



cubic inches, but the calculation in this case is made upon 

 the ^s expired ; and, from the above statement, we may 

 «ee that the evolution of azote goes on diminishing; we 

 have sometimes even found, that towards the close of an 

 experiment it has been almost reduced to nothing. The 

 question now is, whether this increase of azote can be ow- 

 ing to the residual gas contained in the lungs at the be- 

 ginning of the experiment, or whether a portion of oxvgen 

 is not actually exchanged for azote, when pure oxygen gas 

 is respired. 



Here it may be useful to compare the azote found in our 

 former experiments on oxygen, with the present. 



Oxvgen Quantity Inferred 



Gas Gas ex- Defi- respired in Azote Capacitr 



Bar. Therm, inspired, pired. ciency. Time, a minute, evolved. ot'Lungs 



No- , „ 



1. 55 3260 :3I<)3 67 920 318 110 141 



•J. 30 3 70 3420 3362 58 725 4f;i 177 225 



3. 30 15 70 3130 3060 70 8 45 357 187 236 



4. 29-9 51 2668 2544 124 13- 205 105 133 



The greatest increase of azote was in the 2d and 3d expe- 

 riments, when the thermometer was at 70", which might 

 materially influence the results : in the other cases, it was 

 not higher than 33. 



From the experiments of Goodwin, we might be inclined 

 to admit the capacity of the lunge, inferred from the 1st 

 and 4lh experiments, as very possible ; but it seems diffi- 

 cult to conceive that it can amount to 236 or <2'ib cubic 

 inches ; and yet this must be the case, unless a portion of 

 azote is given ofi' from the blood, or there is some process 

 in nature by which it is capable of being produced from 

 oxygen. 



Having, by the kindness of our friend Henry Cline, jun,, 

 been furnished with the lungs of a stout man, about five 

 feet ten inches liigb, t;iken from the body not long after 

 death, and in a sound state, we proceeded to ascertain the 

 quantity of air contained in this organ after the most coni- 

 piete^ expiration, as in death. 



Henry Chne had judiciously taken the precaution to di- 

 vide the tracliea just below the crichoid cartilage, before he 

 opened the thorax ; he then inserted a tube with a brass 

 stop-cock, which he lied firmly to the trachea, and at- 

 tached an empty bladder to the other end. Tlie cock was 

 then turned, so as to communicate with the bladder, and 

 on opening the thorax 31| cubic inches of air were expelled 

 into it. 'I'he weight of the lungs was four pounds one 

 ounce. A very large glass jar being placed in a shallow tin 



Tcssel, 



