754 • Experiments 



oxygen is dissolved in the water in sufficient quantity. A pressure 

 of 15 atmospheres kills them quickly and they cannot live in 7 

 atmospheres. The transparency of the eels allowed us to note a con- 

 siderable slowing down of the heart beats, while the respirations 

 weakened so as to be almost invisible. 



In another part of the book we shall draw conclusions from 

 these last experiments from the point of view of the physics of the 

 earth. It is enough here to note the generality of the fatal action 

 of compressed oxygen, which acts upon warm-blooded animals as 

 well as upon cold-blooded animals, upon vertebrates and inverte- 

 brates, upon animals which live in the water and those which 

 breathe air, upon adult animals and those in the process of develop- 

 ment. Chapters V and VI will permit us to extend this formula to 

 plants, to ferments, in a word, to every living thing. 



Subchapter II 



ACTION OF COMPRESSED AIR AT LOW PRESSURES 

 (FROM 1 TO 5 ATMOSPHERES) 



The great interest attached to the toxic action of oxygen at 

 high tension has caused me, as I said when I began this chapter, to 

 begin this exposition as well as my research by a detailed analysis 

 of the effects of this poison of a new type. I confess that I have 

 long neglected, almost scorned, this study of the effects of slightly 

 compressed air which French and German doctors have so long 

 been testing, as we saw in the first part of this book. I could not, 

 however, help being somewhat interested in it. My researches even 

 gave it a new interest, unknown to former experimenters. 



In fact, the experiments which have just been reported have 

 shown that poisoning by oxygen at high tension first checks the 

 intra-organic combustions, lessens the quantity of oxygen absorbed, 

 of urea excreted, and consequently lowers the temperature of the 

 body in warm-blooded animals. Now it is evident from the experi- 

 ments contained in Chapter III, that the same physiological effects 

 also result from diminished pressure, or, to speak more exactly, 

 from too low tension of the oxygen breathed. 



Quite naturally then it was desirable to know where between 

 these two extremes, which are equally dangerous, is the point 

 where the organic combustions are at their maximum intensity. 



Besides, it was proved by the same experiments that prolonged 



