100 DR. R. ANGUS SMITH PHYSIOLOGICAL EFFECTS OF 



Here the pulse became so weak that it was difl&cult to 

 count the beats. There was also a very unpleasant feeling. 

 The door was opened, and two other young men entered. 

 Of course a good deal of carbonic acid was removed, but 

 not more than from ^ to | per cent. In ten minutes the 

 pulse of the eldest, B., fell from 



79 Inspirations rose from 1 8 



to 75 to 22 



Unpleasantness felt. 



Here, as in the experiment recorded previously, the pulse 

 of A. rose. 



At first it was 63 Inspirations 21 



It rose to 69 rose to 25 



A.'s pulse very feeble. There is always a slight rise at 

 the beginning. This rise was very decided in the case of 

 A. It always results in a fall, and would no doubt have 

 done so in this case had A. remained longer. This, how- 

 ever, would not have been safe, as, even in these two minutes, 

 his pulse was almost imperceptible, and he could not count 

 it himself. 



In the above cases the persons who breathed sat in the 

 lead chamber, and of course the organic matter from their 

 bodies escaped into the air around them. Still we know 

 that the organic matter would not produce these effects 

 without the carbonic acid, simply because when we remain 

 in the chamber much longer without pouring in carbonic 

 acid the pulse does not become so weak, whilst the organic 

 matter is of course accumulated to an extent much greater 

 than it could have been with artificial carbonic acid. 



Whilst I gave abundant credit to the organic matter for 

 doing evil, I could not refuse to blame the carbonic acid ; 

 but as a friend was still dissatisfied with the argument if 



