Contribution to the Pliysiology of Respiration under the Arctic Climate. 151 



I have included a series of preliminary experiments from the 

 winter of 1906; these experiments, which were made in the forenoon, 

 thus after one of the principal meals, and which therefore cannot 

 be directly compared with the later, morning experiments, cannot 

 claim to have the same accuracy and uniformity as the latter; but 

 the results are so considerable owing to the great fluctuations in the 

 barometric height, that the curves may contribute, in spite of smal- 

 ler irregularities in several of the experiments, to illustrate the con- 

 ditions dealt with here. 



We notice at once, that the two curves for the respiration and 

 barometric height lie in the main symmetrically; looking closer, it 

 is seen that the same movement is repeated in the small, in the 

 variations from day to day; a rise in the barometer corresponds to 

 a fall in the respiration-frequency and conversely. The exceptions 

 are few, in the 22 experiments of the preliminary series the varia- 

 tions are 3 times in the same, in all the other cases in the opposite 

 direction. Of the 3 divergent cases, only one is remarkable, the low 

 frequency for ^*'/ii; the temperature (gas-meter) was on this day 

 815° against 15'4° on the preceding and 159° on the next day of 

 the experiments. The experiment only lasted 20 minutes in contrast 

 to the usual 30, and the air of the room was inspired, as it proved 

 impossible to keep the breathing-pipe open owing to bad weather. 

 This was likewise the case during the experiment on ^/12, which 

 was made a couple of hours later in the day than the other experi- 

 ments and only an hour after a light meal. In this case, however, 

 the temperature was 94° against 13° and 11° on the nearest days, 

 and whereas the barometer fell evenly until the ^*'/ii, it fell 25 mm. 

 in less than 24 hours on the ''/]2 — ^/12, which caused a sharp rise in 

 the blood-pressure and various irregularities in the contraction of 

 the peripheral arteries during the following days, both in myself 

 and in 2 other individuals examined. 



In the next series the symmetry of the two curves is also readily 

 seen, and there are but fcAv fluctuations from day to day. The 

 respiration-curve is however somewhat irregular, several strikingly 

 low values occurring, which are certainly due to the very low 

 temperature in the room on these days. The fluctuations are less 

 than in the previously discussed series and the amount of the reduc- 

 tion is approximately the same in both curves. 



In June the symmetry is still present, when we consider the 

 curves as a whole; but in details there is no longer agreement; the 

 course of both is much more even than in the preceding. A single 

 divergent value has already been mentioned. 



In August the respiration-frequency may be regarded as almost 



