Chapter III 

 GENERAL CONCLUSIONS 



The data given in the second part of this work, and the theories 

 which are deduced from them, and which are summarized in the 

 third part, can be condensed in the following conclusions, if we 

 omit the chapters dealing with poisoning by carbonic acid, as- 

 phyxia, blood gases, and other matters a little outside the subject 

 of this book: 



A. The diminution of barometric pressure acts upon living 

 beings only by lowering the oxygen tension in the air they breathe, 

 and in the blood which supplies their tissues (anoxemia of M. 

 Jourdanet), and by exposing them thus to the dangers of as- 

 phyxia. 



B. The increase in barometric pressure acts only by increasing 

 the oxygen tension in the air and in the blood. 



Up to about three atmospheres, this increase in tension results 

 in somewhat more active intra-organic oxidations. 



Beyond five atmospheres, the oxidations diminish in intensity, 

 probably change in character, and, when the pressure rises suf- 

 ficiently, stop completely. 



The result is that all living beings, air-breathing or aquatic, 

 animal or vegetable, complex or monocellular, that all anatomical 

 elements, isolated (blood corpuscles, etc.) or grouped in tissues, 

 perish more or less rapidly in air that is sufficiently compressed. 

 The only exception to this generalization is the spores of certain 

 microscopic organisms. For the higher animals, death is preceded 

 by tonic and clonic convulsions of extreme violence. 



In the vertebrates, the sudden symptoms due to too great oxy- 

 gen tension begin to appear only at the moment when the oxygen 

 goes into solution on coming in contact with the tissues, since the 

 hemoglobin is saturated with it. We can say then that the ana- 

 tomical elements are anaerobes. 



1036 



