Theories and Experiments 235 



Flechner has found that that is not correct .... But if, in lofty 

 places, the air is rarer while the composition remains the same, the 

 oxygen will weigh less: it will furnish less oxygen to the blood. 

 The light of the sun has no effect. 



All the rest of the work is devoted to considerations of the 

 diseases which are prevalent in the mountains. 



The professor of Lyons, Brachet, 00 in the special work which he 

 devoted to our subject, begins by repeating the common idea of the 

 decrease of the weight sustained by the body when the air expands: 



A column of air which raises the barometer only to 13 ¥2 inches 

 must exert upon the body and all the surfaces with which it is in 

 contact an infinitely smaller pressure, the effects of which we can 

 compare to those of the immense cupping-glass of Dr. Junod and which 

 we might, consequently, consider as a sort of suction. The capillaries, 

 which are less compressed, must therefore react less energetically 

 upon the blood and the other liquids which circulate through them; 

 they must therefore be distended and congested by a sort of stasis .... 



The rarefaction of the air explains very well the difficulty and 

 trouble in breathing, but it does not explain the panting and the 

 extreme prostration which the slightest movement causes. 



To explain this new element, Brachet, who has just fallen into 

 so strange an error in physics, expresses the most suitable ideas: 



The panting (he says) results from the darker blood which 

 reaches the lungs and does not find, in the rarified air which enters 

 there, a sufficient quantity of oxygen to revitalize it quickly enough. 

 The lassitude results from the fact that the blood, which is therefore 

 not well aerated, no longer gives the muscles the normal stimulus 

 which they need to contract. 



This view, which is so simple, so clear, and, let us add in ad- 

 vance, so true, did not end the controversy, however. 



In fact, a few months afterwards, Castel, G7 a member of the 

 Academy of Medicine, discussing the question theoretically, ex- 

 presses himself on the subject in the vaguest terms; no doubt, for 

 him, the physiological phenomena observed on lofty mountains are 

 due to the decrease of atmospheric pressure, but, he adds: 



Not that this pressure is, as certain authors have maintained, the 

 immediate agent in the movement of the blood in the most remote 

 arterial ramifications and the veins, but it exerts a direct and constant 

 influence upon contractility, of which the flow of animal liquids is 

 never independent. The contractility is checked to a degree propor- 

 tional to the amount of decrease of atmospheric pressure. 



Finally, in this same year, the celebrated German physiologist 

 Vierordt os made a certain number of experiments upon the effect 



