Chapter VIII 

 VARIOUS QUESTIONS 



In this chapter I deal with a number of questions which have 

 only a somewhat indirect connection with the subject of my re- 

 searches, but which are not, however, foreign to it. Such are the 

 questions of asphyxia and the toxic action of carbonic acid, which 

 has been so often mentioned, especially in the first chapter of 

 this work. 



Subchapter I 

 ACTION OF CARBONIC ACID UPON LIVING BEINGS 



The experiments reported in Chapter I, subchapter II, have 

 shown me that the death of animals confined in closed vessels, in 

 air compressed to several atmospheres, occurs when the tension 

 of the carbonic acid which they have formed by respiration rises 

 to a certain constant value. 



This first observation attracted my attention particularly to the 

 study of the effects of carbonic acid upon living beings, so that 

 this study is connected indirectly to my project. It is the results 

 of these researches that I shall report here. 



1. The Lethal Tension of Carbonic Acid in the Ambient Air. 



I first remind the reader that the tension of a gas T is the 

 product of the two factors, the percentage C and the barometric 

 pressure P. 



In sparrows, as we have seen, death occurs when the carbonic 

 acid tension rises to a value of 24 to 28, when, in other words, one 

 has the equation 



C x P = 24 to 28. 



896 



