J^58 ^- Lindhard. 



done, use a very powerful light rich in ultra-violet rays. And we 

 must remember, that when we once have a recognizable effect of 

 the light on the respiration, it takes some time before this effect 

 disappears. An immediately following "dark experiment" will be 

 quite illusory. 



What we find in the literature seems to me, therefore, rather to 

 be in favour of my view, that the light is a climatic factor of 

 importance. It may be added further, that the same effect, which 

 is caused by the Arctic and the mountain climate, is also found, 

 though less marked, in the sea-climate^. And lastly, various inves- 

 tigators, among others also Zuntz, have shown that similar pheno- 

 mena are to be observed on balloon-journeys. 



What is common to all these different localities is the strong 

 light, but not the rarification, nor the lack of oxygen, nor the 

 amount of moisture, nor the temperature. 



It still remains to mention some experiments made at 

 low temperatures, especially group I of the April 07 experiments 

 and the morning experiments of May 08, in all 8 experiments. To 

 these are joined some few of the experiments mentioned above, 

 where a similar "effect of cold" may with more or less probability 

 be considered to have been present, as also some few of the day 

 experiments of May 08, which are given in the accompanying table. 



It has long been regarded as certain, that warm-blooded animals 

 react towards the cold with increased metabolism. Experiments of 

 Liebermeister, Voit, Rubner, Prince Carl Theodor are cited as 

 proof of this; only a few experiments of Senator point like Specks 

 self experiments in an opposite direction. Later, it has been found, 

 thai warm-blooded animals under the influence of curare lost this 

 property and remained like cold-blooded. Through the investigations 

 of LoEWY^ and Johansson-^ it has been determined, thai the rise 

 under the cold will not appear when the individual experimented on 

 is able to keep his muscles at rest. Sanders-Ezn* was of the 

 opinion, that the metabolism in homoiotherms was different in re- 

 lation to the outer temperature, according as the latter had some 

 influence on the body-temperature or not. If the body-temperature 

 is altered, the metabolism rises and falls with the outer temperature 

 as in poikilotherms. This seems to be based on a confusion of 



1 Ide: Zeitschr. f. physical, u. diaet. Tlierapie. IX, p. 189. 

 '' Pflugers Archiv. XLVI, 1890, p. 189. 

 ^ Skand. Archiv, f. Physiologic. 7, 1897. 

 ' cit. Johansson, ihid. 



