opportunity of using the excellent large gasome* 

 ters of the Royal Institution in London ; and the 

 principal result of them was, that the volume of 

 the air, during the respiration, is so inconsidera- 

 bly diminished, that the real absorption hardly 

 amounts to more than two thirds per cent, of its 

 volume. On the other hand they found, that the 

 carbonic acid gas, just produced, fills precisely 

 the room of the consumed oxygene g*as. As it 

 was known already, that oxygene gas, during its 

 transformation into carbonic acid gas, does not 

 alter its volume, and that consequently 100 cubic 

 inches of oxygene gas, in which carbon had been, 

 burnt, produces exactly 100 c. i. of carbonic acid 

 gas, it was completely proved by ALLEN and 

 PEPYS'S experiments, that no hydrogene is oxy- 

 dated in the lungs that the oxygene is consumed 

 only by the charcoal -and that, for the rest, the 

 blood, according to all appearance > is not oxy- 

 dated, but only emits carbon, (or is decar- 

 bonized). 



These chemists could not observe any other 

 alterations in the composition of the expired air : 

 it had lost no nitrogene, and acquired no other 

 aerial substance, than carbonic acid gas. This 

 constituted about 8 p. c. of the volume of the 



