98 



DR. R. ANGUS SMITH PHYSIOLOGICAL EFFECTS OF 



Table F. — Sitting quiet for an hour in the Lead Chamber 

 in pure air. 



Time. 



Pulse. 



Eespiration. 



4I' e,d^ 



75 



17 



After 10 minutes 



76 

 76 

 76 



77 

 76 

 76 



17 

 17 

 17 

 17 

 17 

 17 



„ 20 ,, 



■30 .. 



AO .. 



„ CO ,, 



„ 60 „ 





From this we learn that the same quiet condition in pure 

 air produced no change. 



Experiments B^ Q, and D^ on the beats of the pulse, 

 seem decisive. The air affects the pulse when the ventila- 

 tion is such that the amount of carbonic acid reaches 0"i8. 

 The question of carbonic acid and organic matter, \iz., 

 which is the most hurtful, must be decided by other ex- 

 periments. My belief is that much is due to the carbonic 

 acid, because the progress of the pulse downwards is so 

 regular, and I believe that the organic matter does not in- 

 crease so regularly. This may not be true at the tempera- 

 ture given, and is another point to be ascertained. 



But leaving out all the details, the great broad fact re- 

 mains that carbonic acid and other emanations from the 

 person diminish the circulation, and hasten the respiration, 

 and that the effect is perceptible when the per-centage of 

 carbonic acid reaches o*i8, or say one-fifth of a per cent. . 

 certainly. If, however, we do not wish to infer too much 

 from one beat of the pulse, let us, for rough practice, say 

 \ per cent. 



Effect on the Pulse and Breathing 



Artificial carbonic acid being inhaled along with the 

 organic exhalations of the body. 



