92 



DR. R. ANGUS SMITH PHYSIOLOGICAL EFFECTS OF 



amount per cent, in the air of the chamber. This experi- 

 ment was the beginning of the inquiry. I expected that 

 the amount of carbonic acid exhaled would diminish^ and 

 with it the amount of strength in the muscles ; but these 

 points could not be reached by the methods employed. The 

 amount of oxygen used is for the time the same, although 

 there is less in the atmosphere. I shall not pretend to say 

 how the health is affected further than this, that a change 

 is observed in the respiration and the pulse. I must 

 leave physiologists to tell what mischief this will ultimately 

 cause; but I cannot doubt that the circulation is diminished, 

 and that the lungs endeavour to compensate for this by 

 more rapid action. How much each person can bear of 

 this change will depend on circumstances which, it appears 

 to me, physiologists cannot estimate. 



Table B. — One Person in the close Chamber. 



Carbonic acid. 

 ist day. 2nd day. 

 After 20 minutes o* 18 per cent o'lg per 



cent. 



40 „ ... 



... 0-32 



)) 



0*36 , 



I hour 



.. 0-49 



)) 



0-49 



80 minutes . . . 



.. 0*62 



„ 



0-64 



100 „ 



.. 074 



)) 



075 . 



2 hours 



.. 0-88 



,, 



0-89 , 



140 minutes... 



.. i"o6 



)> 



i'03 



160 „ 



.. 1*20 



„ 



1*22 , 



3 hours 



.. 1-25 



i> 



i'34 



200 minutes.... 



.. 1-52 



J! 



1-48 



220 „ .... 



•• i'54 



„ 



160 , 



4houi's 







)) 



r8i 



260 minutes... 







)) 



1-98 , 



280 „ 







» 



2*IO , 



5 hours 





>) 



...... 2*25 , 



Ihavenothad time to attend to the full explanati on of each 

 experiment, and some require a continuation of the inquiry; 

 but this last must not be passed over without special notice. 

 The amount breathed every hour is the same — no matter 



