766 



Experiments 



The air of this bell is constantly purified of the carbonic acid 

 produced in it by the respiration of the animal, by action of pipettes 

 P and P' and the washbottle A. Bottles and pipettes contain a very 

 much concentrated solution of potash, the C0 2 content of which 

 was previously determined by the mercury pump and an acid; they 



Jjg 



T3 c 



3 



o £ 



jC a; 

 o cc 



a o 



I 



are operated by a little water motor M, and a set of pulleys and 

 eccentrics which can be understood by a mere inspection of the fig- 

 ure; the agitation of flask A is so energetic that it seems filled with 

 foam. The air which passed through the alkaline solutions follow- 

 ing the course iP'PpAp'K, returns to the bell absolutely freed 

 of its CO,. 



