DIVERSE COMPONENTS 



341 



The equilibration diagram for carbon dioxide (fig. 171) shows 

 enormous responses to increased contents. Neither in increased 

 nor in decreased contents is there a known change in rate of inter- 

 nal (chemical) production. Recovery from deficit is limited to sup- 

 pression of loss alone. This fact was described by Haldane and 

 Poulton ('08); after forced breathing, apnea persists until the 



-0.02 



+0.01 



■K).02 



-0.01 



CO2 Load 

 li+er^/kc). 



Fig. 171. Kate of carbon dioxide exchange in relation to load of carbon dioxide. 

 Man in steady states of load. Excesses were produced by inspiring uniform mixtures 

 of carbon dioxide and air; deficits by overbreathing for periods of time during wMch 

 alveolar and expired airs were collected. Gain is by metabolic production; loss is by 

 expired air. Loads are in liters of COa/kg. of Bq; rates in liters of COoAg- l"". Data 

 in negative loads are from Liljestrand ( '16) ; in positive loads from Campbell et al. 

 ('14); point H from Haldane and Poulton ('08). 



mean alveolar tension of carbon dioxide is slightly less than the 

 usual (the apnea point of Nielsen, '36). 



To estimate the content of carbon dioxide in the body, reliance 

 may be placed in chemical analyses of cat and dog (Irving et al., 

 '32). Roughly 1.06 liters/kg. are found at balance, and loads 



