Conti-ibution to the Physiolog}' of Respiration under the Arctic Climate. 155 



higher temperature than any other experimental series. Further, it 

 is also possible that the value for February would Ьал^е been lower 

 than that for January. But there are two circumstances which 

 must be remembered, especially as regards the metabolism. The 

 one is, that the food was different in Copenhagen from that on the 

 Expedition; the second, that the control experiments were made in 

 a sitting position, whilst all the Greenland experiments were carried 

 out in a kneeling position. How much the change of food means 

 I cannot venture to say, though I do not believe that the difference 

 is so very great. The different position has certainly very little 

 influence on the results. After I had become accustomed to it, the 

 kneeling position was very comfortable and only occasionally tired 

 me, which the sitting position could also do if it were maintained 

 without change during the experiment. The most probable thing 

 is, that none of the reasons mentioned is the single cause, but that 

 the difference is due to the interplay and conjunction of more or 

 fewer of them. 



There is thus an increase in Greenland of the respiratory meta- 

 bolism during the light period in contrast to what occurs in winter. 

 The increase is evident, amounting to 16 "/o of the minimum value 

 or ca. 7 times the standard deviation of the lowest series, and in no 

 case, therefore, can it be due to the contemporaneously increased 

 total volume of air respired. 



Just as in the other cases mentioned we have here also analo- 

 gies from the mountain experiments. 



ZuNTZ^ gives for self-observations in 1901: 



CO 2 cc per minute 

 Brienz 1830 average of 3 experiments 



Rothorn 192-7 _ - 4 — 



Monte Rosa 2559 — - 3 — 



The rarification of the air is given as the cause of the phenom- 

 enon, in spite of the fact, that no support is obtained in this case 

 either from the experiments carried out in the pneumatic room, 

 where the amount of oxygen used up, even with a considerable 

 rarification of air, is less than in the mountains. 



Jaquet and Stähelin"^ repeatedly point out this disagreement 

 between experiment and observation and mention as other causes 

 of an increase of metabolism: light, heat-radiation, dry air, tempera- 

 ture. Their own experiments for the rest do not explain very much; 



1 Höhenklima u. Bergwanderungen. Chap. VIII. 

 ^ 1. с 

 XLIV. 12 



