158 



daily consumed. MM. Lavoisier and Seguin esti- 

 mated the mean consumption of oxygen gas, every 

 24 hours, at 46037.38 cubic inches, or 15661.66 

 grains : and the same illustrious philosopher, on re- 

 peating his experiments in the following year, ob- 

 tained nearly the same results, an account of which 

 he was employed in drawing up, when cut off* by 

 the murderous tyranny of the French government. 

 Upon the estimate of Mr Davy, that 31.6 cubic 

 inches of oxygen gas are consumed every minute, 

 the amount, in 24 hours, will be 45504 inches, a 

 quantity equal to 15471.36 grains. This estimate, 

 says Dr Bostock, coincides nearly with that of La- 

 voisier, though it was obtained by a different pro- 

 cess, and by the use of a different apparatus : we 

 may therefore conclude, he adds, that between 45 

 and 46,OOO cubic inches, or about 15500 grainy 

 2 Ibs. 8 oz. troy, is th,e average quantity of oxygen 

 consumed in 24 hours by the respiration of an ordi- 

 nary man*. 



127. Notwithstanding, however, the necessity of 

 oxygen gas to the continuance of respiration, and 

 the great quantity of it that is thus daily consumed, 

 many facts tend to prove, that, by the very consti- 

 tution of that function, a necessary limit is placed 

 to its consumption : and that this limit is determined, 

 not by the purity of the air employed, but by some 

 circumstances inherent in the animal system. It has 

 beeji already observed (14. 40.), that the growth of 

 vegetables is retarded by a great superabundance of 



' K^ay on Respiration, p. 84-, 



