Contribution to the Physiology' of Respiration under the Arctic Climate. 133 



The irregular distribution of the deviations in relation to ц is 

 due partly to the fact, that there are some few large deviations in 

 a relatively uniform series, partly to the fact that only one decimal 

 has been taken account of in the calculations; a series of numbers, 

 however, which just vary as much as [i, will undoubtedly prove to 

 fall partly outside, partly within this limit on making closer calcu- 

 lations. 



There is still one thing more in this paper to which I w^uld 

 refer. Hasselbalch has judged the increase in the amount of the 

 "dead space", produced by the mask and the valvular apparatus, to 

 be 50 cc, which is too low a value in my opinion. I have calcu- 

 lated with 150 cc, with the same valves and on the whole the same 

 arrangement, after measuring the space with water. Certainly, there 

 may be some difference in the "dead space" in the mask and this 

 is just difficult to measure; but the difïerence can never be so great 

 as 100 cc. The "dead space" enters into the calculations of the 

 percentage of the alveolar carbonic acid; but as these two quantities 

 are not simply proportional but vary together according to a more 

 complicated function, the effect of any change in the amount of the 

 "dead space" on the percentage of carbonic acid cannot be overlooked. 



Turning to my own investigations, these give the following 

 results with regard to the climatic factors, air-pressure and tem- 

 perature. 



In contrast to Haldane and Priestley's results, that the or- 

 dinary fluctuations of the barometer are without influence 

 on the alveolar carbonic acid tension, I find both from control 

 experiments as well as from the Greenland series a distinct tendency 

 on the part of the two quantities mentioned to vary in the same 

 direction. To express this tendency in numbers is difficult from 

 the available material, as the experiments were not arranged with 

 that object in view and are thus not "clean" in this regard; thus, 

 the influence of the air-pressure interferes with the effect of the air- 

 temperature and both produce independently or in conjunction com- 

 paratively superficial irregularities on the great annual variation; if 

 we consider the separate series a definite tendency will, as said 

 before, be unmistakable. 



It is natural to assume beforehand, that there is no difference 

 in principle in the effect of small and large fluctuations of the 

 barometer; and the movement here also goes in the same direction 

 as that found in mountain experiments. The reason why Haldane 

 and Priestley have not taken this condition into consideration is, 

 partly, that their values for the alveolar carbonic acid tension vary 

 for other reasons much more than mine, and partly, that the flue- 



