280 Historical 



In other words, the explanation given by the learned professor 

 can be applied, according to him, only to laboratory experiments 

 performed on animals; mountain climbers and aeronauts are not 

 amenable to it. 



The argument brought by M. Gavarret against the part which 

 so many authors had given to the decrease of the weight sustained 

 by the body seemed to have exposed this error; the important ex- 

 periments of Rudolph von Vivenot 117 seemed, on the other hand, 

 to give it new authority. In fact, the Viennese physician proved 

 very clearly that in rarefied air the depth of the respirations and 

 the respiratory capacity diminish considerably. 



These experiments were made at the Johannisberg establish- 

 ment, in the apparatuses set up by Dr. Lange; some had as their 

 purpose the study of compressed air, and those we shall discuss 

 later; the others, of which we shall speak now, related to rarified 

 air. 



When we take into account the altitude of Johannisberg, where 

 the average height of the barometer is 742 mm., we see that if 

 the decompression reached in the apparatus was 318 mm., the 

 actual pressure was 424 mm., which corresponds to an altitude of 

 4470 meters above sea level. 



Under these conditions, as I said a moment ago, the amplitude 

 of the respirations diminished considerably: 



Dr. Lange and Dr. Mittermaier, whose pulmonary capacity shortly 

 before at normal pressure had been 3942 cc. and 4237 cc, could only 

 with the greatest efforts expire 3448 cc. and 3842 cc, of air which 

 was admitted to the receivers of the spirometer. Their respiratory 

 capacity therefore had diminished 494 cc. and 394 cc. respectively. 

 On an average, we can deduce from the above figures as a normal 

 average respiratory capacity 4090 cc, as respiration in rarefied air 

 3646 cc, consequently as average decrease of pulmonary capacity 444 

 cc, to which we must add that these 3646 cc. of rarefied air represent 

 only 2084 cc. of normal air. (P. 7 of the separate printing.) 



The frequency of the respirations has considerably increased, 

 working inversely: 



The number of respirations rose in me from 14-15 to 18; in 

 M. de G. . . ., from 17 to 21, and at another time, from 17-18 to 19; 

 in Dr. Lange, from 15 to 21; in Dr. Mittermaier, from 7.5 to 9.5 per 

 minute. As to the consecutive duration of this effect, it could not be 

 noted, because no observations were made following the experiments 

 in rarefied air. (P. 11.) . . . 



As to the depth and rhythm of respiration in rarefied air, an in- 

 crease in the depth of the inspirations is noted. This, then, is the 

 first case in which the effect of rarefied air seems to agree with that 



