NORMAL PROCESSES OF ENERGY METABOLISM 523 



the driving mechanism, absorbers and gasometers being set up in the 

 cellar immediately below the respiration chamber (Fig. 5). The air 

 of the chamber is cooled by means of a stream of water passing through 

 a grid of pipe placed near the ceiling of the chamber. Besides the main 

 ventilating tubes which connect with the CO 2 absorbers (b) other tubes 

 penetrate the walls of the apparatus for recording the internal pressure, for 

 admitting oxygen and for withdrawing a sample of air for analysis. The 

 C0 2 absorbers are alternately raised and lowered by means of a walking 



Fig. 5. Respiration apparatus of Hoppe-Seyler. A, respiration chamber; B, 

 apparatus for raising and lowering carbon dioxid absorbers; C, engine; D, gasometer 

 filled with oxygen; (}, meter for measuring sample. 



beam operated by a gas motor. Air is thereby alternately withdrawn and 

 returned to the chamber after absorption of its carbon dioxid. 



Oxygen is admitted from the gasometer D through a gas meter G after 

 passing first through a water flask to prevent evaporation of water from 

 the meter. 



The carbon dioxid absorbed is determined exactly as in the Regnault- 

 Reiset method by discharging the CO 2 from the KOH and collecting it 

 again and weighing. This amount obviously must be corrected by analysis 

 of the air residual in the chamber at the end of an observation. 



Oxygen is determined by reading the gas meter and correcting the 



