Compressed Air; Low Pressures 



759 



of its carbonic acid; the potash solution was then analyzed in the 

 mercury pump. 



But to measure the regular respirations, the arrangement was 

 more complicated; I had to have an apparatus which operated 

 without the least attention, for we know how easily the respiratory 

 movements are modified, when one wishes to examine them. The 



arrangement in Figure 64 gives excellent results, as many test ex- 

 periments have shown me. 



A rubber mouthpiece, which is applied to the dental arches and 



