Theories and Experiments 



219 



Change in 



Oxygen Carbonic body 

 consumed acid jormed temperature 



1. Rabbit, normal pressure 7.05 6.16 + 0.2° 



Rabbit, rarefied air 6.43 5.02 — 2 '° 



2. Rabbit, normal pressure 6.53 6.56 + 0.3° 



Rabbit, rarefied air 5.97 4.56 — 2.2° 



3. Rabbit, normal pressure 12.08 8.55 — 1.3° 



Rabbit, rarefied air 9.96 7.60 — 1.3° 



4. Cat, normal pressure 9.50 — 0.5° 



Cat, rarefied air 6.93 — 4.2° 



5. Cat, normal pressure 8.52 6.20 — 0.3 



Cat, rarefied air 7.66 6.12 — 7.°^ 



6. Dog, normal pressure 13.26 9.12 — 1.7 



Dog, rarefied air 10.91 9.11 — 4.2° 



7. Dog, normal pressure 13.19 7.65 — 4. 



Dog, rarefied air 10.39 6.63 — 6.2° 



8. Guinea pig, normal pressure 8.49 6.27 — 0.4 



Guinea pig, rarefied air 7.37 6.56 — 2.6° 



9. Guinea pig, normal pressure 11.41 9.10 — 1.3 



Guinea pig, rarefied air 9.58 8.42 — 4.8 



Legallois draws from these experiments, in reference to the 

 subject which interests us here, the following conclusion, which 

 shows admirable sagacity: 



Since the mere rarefaction of the air, carried far enough to lower 

 the barometer less than 30 centimeters, is enough to chill the animal 

 which breathes it, the result is that the cold experienced on lofty 

 mountains does not depend solely on the coldness of the atmosphere, 

 and that it has in addition an inner cause, which acts through respi- 

 ration. (P. 59.) 



What a contrast between these clear experiments, these precise 

 conclusions and the confused mass of so-called explanations which, 

 in that same year, Dralet - n gave both of the discomforts and the 

 improved conditions experienced on lofty places! 



The air on mountains of moderate height is more healthful than 

 that on the plains ... If we consider, moreover, that the pressure of 

 the atmosphere is less as we ascend, we shall not be surprised that 

 the dwellers on the plain are in better health on the Pyrenees, eat 

 with more appetite, and that the elasticity of their lungs gains new 

 strength there. 



But the man who is approaching the region of snow will not find 

 an air so favorable to the animal economy; since vegetation, accord- 

 ing to the observation of M. Ramond, is practically absent from these 

 wild spots, the nitrogen is not absorbed by the organs of plants, and 

 lessens the wholesomeness of the air by its abundance. 



MM. Vidal and Reboul have proved that the quantity of vital air in 

 the atmosphere at the summit of the peak of Midi in Bigorre was about 



