Compressed Air; O, Poisoning 



713 



The bird is removed; it has large ecchymoses on the cranium. 

 Its rectal temperature is only 30°. 



Remains very sick and dies in the night. 



The data which have just been given permit us from now on 

 to describe the violent symptoms due to compressed air, to too 

 high oxygen tension, and to prepare the physiological analysis of 

 this poisoning. 



The first question which we should ask ourselves is as follows: 

 at what oxygen tension do the convulsive symptoms appear? 

 Let us collect in a table (Table XIV) the experiments of Chapter 

 I and those which precede. 



Table XIV 



We see from an examination of this table that the convulsions 

 begin to appear with an oxygen tension expressed by the figure 

 300, which, if we used pure air, would correspond to about 15 

 atmospheres. 



The harmful effects were observed much sooner, as graph A of 

 Figure 22 shows, which expresses the proportion of oxygen re- 

 maining in the compressed air in which the birds died, when we 

 took care to eliminate the carbonic acid formed. The harmful 

 effects are very clear beginning with 6 and especially with 12 

 atmospheres. 



But the convulsions appear surely only between 15 and 20 

 atmospheres. Experiment CXX, in which a linnet was taken to 

 20 atmospheres of air, shows their appearance; only they were 



