348 Historical 



De Saussure gave one to believe, in fact, that the respiratory ac- 

 celeration could compensate lor the decreased density of the air. 

 Now he certainly knew that that was not the case, and that on the 

 summit of Mont Blanc neither the number nor the amplitude of 

 the respirations doubled the pulmonary ventilation. 



This explanation was accepted by all the authors who followed 

 de Saussure. Halle and Nysten (page 217), Courtois (page 218), 

 Gondret (page 220), Clissold (page 223), von Humboldt (page 

 227) , Brachet (page 235) , Lepileur (page 236) , A. Vogt (page 237) , 

 Pravaz (page 239), Marchal de Calvi (page 240), Meyer-Ahrens 

 (page 243), Lombard (page 244), Longet (page 250), etc., repro- 

 duced it in different forms. Some were satisfied with speaking, as 

 de Saussure had done, in a rather vague manner of the insufficient 

 quantity of air brought into the lungs at great heights; others, mak- 

 ing more definite statements, declare that, since less oxygen reaches 

 the lungs in a given time, less of it must be absorbed by the blood, 

 and hence the symptoms; some, like Longet, deny this conclusion, 

 affirming that "the person who dwells on the mountains .... 

 compensates by more frequent inspirations, so that . . . the same 

 quantity of oxygen can be absorbed in the same time" (page 250) . 



M. Martins criticized this evident mistake; he declared that 

 there must be a lessened oxygenation of the blood resulting from 

 this insufficient pulmonary circulation, and hence "a physiofogical 

 cause of cold peculiar to high altitudes, and probably the principal 

 among all those causes which bring on the symptoms known by 

 the name of mountain sickness" (page 254) . 



But we have revealed the fundamental objection which Pay- 

 erne (page 240) raised against the theory of de Saussure. In his 

 opinion, there is quite enough oxygen in the air, even on the sum- 

 mits of the highest mountains attained, to satisfy the needs of 

 respiration and to meet the requirements of the combustions in- 

 creased by the work of ascent. 



Lombard alone (page 251) seems to be affected by the cal- 

 culations of Payerne; he makes no objection to them, and admits 

 that "even at altitudes of 7000 meters, the atmosphere can furnish 

 man with a quantity of oxygen sufficient to maintain respiration" 

 (page 252). Nevertheless he drew the conclusion "that an in- 

 sufficiently oxygenated blood reaches the different organs . . . This 

 is the cause of a considerable part of the disturbances which occur 

 in innervation and motility" (page 252) . 



In another part of this book, I shall discuss thoroughly the ob- 

 jection of Payerne, and I shall show how much truth it contains. 



