CHANCES PRODUCED IN AIR BY R ESPIR ATION. 187 



the scale of the watei gasometer, and it was again filled with 

 common air to the usual division on the scale. This occu- 

 pied but a very short space of time. The operator, without 

 taking his lips from the tube, therf filled twelve more of the 

 mercurial gasomeiers, which were registered as before, and 

 he continued to breathe in the 12th, until the water gasome- 

 ter was again replenished ; eleven more were then filled, and 

 portions saved from each r the experiment was completed by 

 a forcible expiration of l6G cubic inches into the 12th ; and 

 this last portion being left for an hour and a half was not 

 perceptibly diminished in volume. 



Cub. inches 

 Therm. of common air Cub. inch. 



Barom. Faht. Time. inspired, expired. Defic. ' 



29-85 68° 24' 37" 9SyO 9872 18 



The breathing was so nearly natural that the operator was 



scarcely fatigued, and thought that he could have gone on 



for a much longer time. 



The smallness of the deficiency, notwithstanding the ex- Increase or de- 



periment occupied 244- minutes, is a striking circumstance, creas ^ of a J f 

 r . .' merely aca- 



and leads us to suspect still more strongly, that the defi- dental. 



ciency principally arises from the impossibility of alwayi 

 bringing the lungs to the same state after forcible expira- 

 tion. 



100 parts of the mixture of expired gas gave Component 



8 carbonic acid parts of theex- 



13 oxigen, P ired « as - 

 79 azote, 



100 



Calculation for Carbonic Acid. 

 100 : 8 : : 9872 : 789'76. 



So that 789*76 cubic inches of carbonic acid gas were given Carbonic acid, 

 off in 24^ minutes, which gives thirty-two cubic inches per 

 minute. But here it must be noticed that the respiration 

 was more rapid than in the 1 1th experiment, and a larger 

 quantity of carbonic acid given off in the same time. This 

 agrees with the 12th experiment. 



We 



