16 



August Krogh and Млии-: Krogh. 



Methodics. 

 1. The respiration experiments. 



Our respiration chamber was constructed mainly on the Jaquet 

 principle. A current of air was sucked out at an approximately con- 

 stant rate, while fresh air was allowed to enter through the leaks in 

 the chamber, which was so far tightened that a slight negative pres- 

 sure of about 1 mm. water was maintained. The air current was 

 produced and measured by the revolutions of a large gas meter.. Con- 



Fig. 7. The respiration cliamber in course of erection. 



tinuous samples representing the average composition of the outgoing 

 air for certain periods were collected and afterwards analysed for 

 carbon dioxide and oxygen, and from these analyses, combined with 

 the analyses of the atmospheric air entering the chamber and the 

 corresponding volumes of air, the respiratory exchange of the subjects 

 was calculated. As however our respiration chamber was rather large 

 (5.2 m^.) we found it necessary to take into account also the changes 

 in composition of the air in the chamber. Intermediate samples 

 showing the composition of the air in the chamber at the moment 

 were therefore drawn at the end of each period. 



By the construction of the apparatus it had to be borne in 

 mind that it should be erected in the open and had to be carried by 

 hand over rough ground for a considerable distance. The chamber 



