Contribution to the Physiology of Respiration under the Arctic Climate. 145 



We again find here the analogy with Zuntz and Loewy's 

 mountain-experiments. In "Höhenklima und Bergwanderungen", for 

 example, the following series of numbers are given. 



Monte Rosa 1079 1495 



The irregularity in the first column is due to the varying fre- 

 quency of respiration; in both cases the total volume of air respired 

 increases. Of the 22 persons examined by Zuntz and Loewy, only 

 2 showed reduced total volume of air respired on Monte Rosa; in 

 all the others it was increased and remained so, even rising further 

 during the stay at the top. We may believe, however, that a kind 

 of adaptation took place; it is mentioned, that Zuntz on his first 

 Alpine climb to the top of Gnifetti had a total ventilation of 

 8431 cc, on a later visit 7613 cc. per minute; but it is likewise 

 mentioned, that Zuntz stayed for 6 days on Col d'Olen on his first 

 journey before the climb. 



If the increased volume of air respired is due to the light, 

 "adaptation" in this connection is a superfluous supposition. The 

 effect on the respiration will then be a function of the time passed 

 in the strong light, and it will not be, or only secondarily, depen- 

 dent on the altitude. 



Jaquet and Stähelin^ on Chasseral (1600 m.) found quite a 

 small decrease in the total volume of air respired, but a small in- 

 crease in the depth of the single respiration; but their results do 

 not give any definite basis for the changes found and their experi- 

 ments were of very short duration. 



It is worth mentioning that Chasseral was chosen, because it 

 has a damp climate with relatively few chemical light-rays. 



Hasselbalch^' found unchanged total volume of air respired 

 after the light-bath but an increase in the depth of the single respi- 

 ration, as the frequency was reduced; but this again means that the 

 effective air respired was increased. 



Nor do these investigations come into conflict with my view, 

 that the light is the cause of the changes in the respiration in Green- 

 land. Granted that it is the carbonic acid tension, which is deter- 

 minative of the activity of the respiratory centre, then the increased 



1 1. с 2 I. С 



