Chapter III 



PHENOMENA PRESENTED BY ANIMALS 



SUBJECTED TO PRESSURES LESS THAN 



THAT OF THE ATMOSPHERE 



The phenomena presented by animals subjected to a decrease of 

 pressure are exactly those which were noted in mountain travellers 

 and aeronauts; however, I have some interesting details to add to 

 what is already known. But I do not hesitate to confess that since 

 these phenomena are of a purely descriptive nature, it seems to 

 me that an exact analysis of them should be made only after a 

 sufficiently detailed study of their cause; interest in them was 

 obviously a minor matter. 



I think, however, that I should report here the details of some 

 experiments. It will then be easier to analyze the observations 

 made and to group them around the principal physiological func- 

 tions. But the conclusions which we draw from them will be sup- 

 ported equally by the numerous experiments reported in the first 

 subchapter of Chapter I, and the second subchapter of Chapter II, 

 experiments which I thought it unnecessary to describe again here. 



After detailing these symptoms, I shall compare them with those 

 presented by animals asphyxiated in closed vessels at normal 

 pressure; I shall then deduce from all these facts the method which 

 must be used in warding off the dangers of decompression, and I 

 shall report the experiments carried out according to this method 

 upon animals and even upon man. 



660 



