CHAP. V. 



OF THE SOURCE OF THE CARBON IN VE- 

 GETABLES AND ANIMALS BY WHICH 

 THE CHANGES IN THE AIR ARE EF- 

 FECTED. 



i 



131. IN the preceding chapters, it has been 

 generally concluded, that the oxygenous portion of 

 the air is converted into carbonic acid by the pro- 

 cesses of germination and vegetation, and by the re- 

 spiration of animals : we must therefore presume 

 that seeds, and plants, and animals, in some way, 

 furnish the carbon whereby the acid^n question can 

 be formed. To inquire into the immediate source 

 of this carbon is the object of our present investiga- 

 tion. 



1 32. It appears, from the results of experiments al- 

 ready related (1.), that if seeds, in a dry state, be ex- 

 posed to atmospheric air, they neither suffer any 

 change themselves, nor produce any on the air in con- 

 tact with them : but that if they be confined in water, 



