RESPIRATION. 



373 



registered. From the amount of water and carbon dioxid thus ob- 

 tained the amounts of both in the total air breathed are calculated. 

 The water and carbon dioxid previously present in the air are simulta- 

 neously determined by a corresponding absorption apparatus and de- 

 ducted from the amounts obtained from the respired air. As the 

 apparatus is traversed constantly by a column of air of normal 

 composition and the waste products removed as rapidly as discharged, 



FIG. 179. REGNAULT'S AND REISET'S RESPIRATION APPARATUS. A. Bell-jar for the 

 reception of the animal, surrounded by a compartment, B, containing water. 

 N, N, N. Reservoirs of oxygen communicating, on the one hand, with the animal 

 chamber, and, on the other hand, with pressure bottles, P, by which the oxygen 

 is driven into the animal chamber. G, G. Aspiratory bulbs containing sodium 

 hydroxid in solution for the absorption of the carbon dioxid. The bulbs are 

 given an alternate up-and-down movement by a falling weight or electric motor. 



the experiment can be continued for periods varying from six to 

 twenty-four hours without detriment to the subject of the experiment. 

 With those forms adapted only for animals Regnault's and 

 Reiset's, or Jolyet and Regnard's it is possible to determine simul- 

 taneously the absorption of oxygen and the discharge of carbon 

 dioxid. As the apparatus employed is completely closed, the carbon 



