ON RESPIR.ITIOX. Q^Q 



Calculation for Carbonic Acid. 



No. 1. 230. 15min. 100 : 6-5 ;: 250 : 16-25 Calculation for 



2. 250. 13min. 100 : 7-5 : : 250 : 18-75 "^ ''""ic acid. 



3. 250. 17 min. 100 ; 6 : : 250 : 15 



66. - 100 : 6 :: 66 : 396 



45 53-96 



The quantity of carbonic acid evolved in 45 minutes was 



therefore 53-96 cubic inches, or at the rate of 1-19 cubic 



inches per minute. 



The foregoing experiments seem to prove, 



1. That when atmospheric air alone is respired, even by General con- 

 an animal subsisting M'holly upon vegetables, no other ^^"^"^"^' 

 change takes place in it, than the substitution of a certain 



portion of carbonic acid gas for an equal volume of oxigen. 



2. That when nearly pure oxigen gas is respired, a por- 

 tion of it is missing at the end of the experiment, and its 

 place supplied by a corresponding quantity of azote; the 

 portion evolved in a given time being greater in the early 

 than in the later periods. 



3. That the same thing takes place when an animal is 

 made to breathe a mixture of hidrogen and oxigen, in which 

 the former is in nearly the same proportion to the latter, as 

 azote to oxigen in atmospheric air. 



4. That an animal is capable of breathing a mixture of 78 



parts hidrogen and 22 oxigen for more than an hour, with- / 



out suffering any apparent inconvenience. 



5. That the excitability of an animajl is much diminished 

 when he breaths any considerable proportion of hidrogen 

 gas, or that it at least has a tendency to produce sleep. 



6. That there is reason to presume an animal evolves less 

 carbonic acid gas during its sleeping, than in its waking 

 hours. 



7. That the lungs of a middle sized man contain more than 

 100 cubic inches of air after death. 



These experiments have been conducted without reference The facts not 

 to any particular theory, and indeed some of the results ^^J^j^^ ^*^ 

 were so contrary to our preconceived opinions, that we 

 have been induced to bestow more than ordinary attention 

 «n the subject. Confident, however, that all those who 



repeat 



