147 



the same things take place in the respiration of the 

 superior animals, and of man. Mr Davy confined 

 a small mouse in a jar, inverted over mercury, and 

 containing fifteen cubic inches of atmospheric air, 

 previously deprived of its carbonic acid by long ex- 

 posure to the water of potassa. In 55 minutes, the 

 animal was taken out apparently dying,- and of the 

 quantity of oxygen gas originally present in the jar, 

 2.6 cubic inches had disappeared, and two of car- 

 bonic acid were produced. In another experiment, 

 where a mouse was confined in 15.5 cubic inches of 

 the same air, 2.7 of its oxygen gas, in nearly the 

 same time, had disappeared ; and 2.1 of carbonic 

 acid were formed *. Mr Davy himself breathed 

 141 cubic inches of air one-fourth of a minute, ma- 

 king one inspiration and one expiration, seven or 

 eight different times : and he found, by analysing 

 the respired air, that the quantity of oxygen gas lost 

 in each respiration, was from five to six cubic inch- 

 es, and that of carbonic acid produced from five to 

 5.5 cubic inches f. Dr Henderson, on examining 

 10O parts of the air which he had respired four mi- 

 nutes, found, in one experiment, that of the ^ 



of oxygen gas originally present, ^ had disappear- 

 ed, and j~ of carbonic acid were produced : in 

 another, ^ of the oxygen gas were lost, and its 

 place was supplied by of carbonic acid : and 

 when, in a third experiment, the loss of oxygen gas 

 fell between the foregoing numbers, or was ~, so 



* Researches, p. 437. 443. f Ibid. p. 43.1, 



K2 



