218 Historical 



not suffice to bring to the lungs the quantity of air necessary for the 

 maintenance of life, and that life would finally be extinguished, as it 

 is in asphyxia, for lack of the principal agent of respiration. Death 

 in this case might be preceded by various phenomena unrelated to 

 respiration, such as emphysema and different hemorrhages due entirely 

 to the great expansion of all parts of the body. 



Here again we find, applied to respiration, the explanation 

 already given by de Saussure; as to hemorrhages, Halle and Nysten 

 persist in attributing them to the decrease of the weight sustained 

 by the body. 



The same combination of explanations is expressed with greater 

 clearness and moderation in the thesis of Courtois: 27 



Most of these phenomena depend at the same time upon changes 

 which occur in the weight of the air and upon the varying quantity of 

 oxygen which this fluid contains in the same volume, depending upon 

 whether it is condensed or rarefied; thus chemical phenomena compli- 

 cate those which depend upon the weight of the air. (P. 17.) 



At the same epoch there appeared a remarkable work, which 

 deserved more attention from physiologists, and which nevertheless 

 remained almost completely unknown, at least in the part which 

 interests us. I must even confess, not without some embarrass- 

 ment, that I did not know of its existence until I was doing biblio- 

 graphic research necessary for the preparation of the first part of 

 this work, after all my experiments had been completed. 



In his researches on animal heat, Legallois 2S was led to compare 

 the variations in temperature of warm-blooded animals with the 

 quantity of oxygen which they absorb in a given time. Among 

 the causes which might act upon this absorption, he considers the 

 rarefaction of the air, as a means "of lessening the quantity of 

 oxygen contained in the air in which the animal is confined". 

 Legallois kept the animals in closed vessels (the manometer, as he 

 calls it, measured 41 liters) during the whole experiment; he has 

 nowhere specified the degree of decompression to which he had 

 subjected them, but it is easy to conclude from his accounts that 

 he never reached a half-atmosphere. I summarize in the following 

 table the results of his experiments; the comparative test, made for 

 each animal at normal pressure, lasted the same time, of course: 



