THE PHEXOMENA OF HUMAN RESPIRATION. 
31 
lively a mean of 9'29 and 10'51 litres, while another expired a mean of 11'30 litres 
for 1 gTin. carbonic acid. No doubt, the less the volume of air inspired for the 
combustion of a certain weight of carbon the more readily the oxygen taken into the 
lungs finds its way into the blood, and consequently the more perfect the action of 
the respiratory organs. In the present case, one of the suljjects submitted to experi¬ 
ment was 60 years of age, and he breathed 11‘30 litres, against 10\51 litres and 
9'29 litres for young men both 23 years of age; although of the same weight, one 
stronger physically and with a more fully-developed chest breathed (expired) 9'29 
litres, against 10‘51 for the other, to burn the same weight of carbon in his body. 
