Contribution to the Physiology of Respiration under the Arctic Chmate. 147 



pressure, which makes the respiration further unnatural. Lastly, 

 the receiver could only hold some few litres, so that the whole ex- 

 periment could only last quite a few minutes. It may certainly be 

 regarded as impossible to obtain in this manner information regarding 

 the respiration-frequency of a quietly breathing person. 



In his oft-cited work Hasselbalch ^ has devoted some space to 

 the detailed discussion of the respiration-frequency. It may be con- 

 sidered as certain from his investigations, that the chemical light- 

 bath reduces the frequency, since it lowers the tone of the capillaries 

 of the skin. Hasselbalch further concludes, that the state of con- 

 traction of these skin blood-vessels must also have some influence 

 on the frequency under ordinary conditions, as he proceeds to show 

 in several regards. Thus, there is a distinct decrease in the frequency 

 after defæcation; in agreement with Potain's investigations" there 

 is higher frequency immediately after waking up than later, when 

 one has become completely awake, as the result of the contraction 

 of the peripheral vessels during sleep. It is likewise shown, that 

 there is a dependence on the air-temperature, rising frequency with 

 falling temperature. The material is however very imperfect on 

 this point. 



ZuNTZ and LoEWY ' find that the respiration-frequency at high 

 altitudes behaves in different ways, sometimes decreasing, sometimes 

 increasing. They found, as a rule, first increased then reduced 

 frequency, as they gradually changed their station. In 2 out of the 

 6 individuals the frequency increased on the whole, in the other 4 

 it decreased. In one of the two with increasing frequency an increase 

 in the depth of the single respiration also occurred however at the 

 same time; as already mentioned, the total volume of air respired 

 always increased at the high altitudes; in the other person the 

 volume of the expiration remained unchanged. It might be thought 

 now, that it was difficult or impossible for the individuals concerned 

 to show the increase in the respiratory movements, which must be 

 the consequence of a reduction in the frequency accompanied by 

 increased total volume of air respired, and that the frequency must 

 therefore have been unusual or abnormal. It is also possible, again, 

 that the opposing forces, which are operative in this case, may 

 result in a different way according to the personal peculiarities of 

 the individual. 



The rule is that the frequency decreases, as shown by the fol- 

 lowing table: 



1 Det kemiske Lysbads Virkninger. Hospitalstidende 1905. 



2 cit. Hasselbalch. 1. c. 



^ Höhenklima und Bergwanderungen. Kap. XL 



