C 189 3 



the oxygene lost, about an equal volume of carbonic 

 acid appears. 



The effects of azote in vegetation are not distinct- 

 ly known. As it is found in some of the products of 

 vegetation, it may be absorbed by certain plants from 

 the atmosphere. It prevents the action of oxygene from 

 being too energetic, and serves as a medium in which 

 the more essential parts of the air act; nor is this cir- 

 cumstance unconformable to the analogy of nature; for 

 the elements most abundant on the solid surface of 

 the globe, are not those which are the most essential 

 to the existence of the living beings belonging to it. 



The action of the atmosphere on plants differs 

 at different periods of their growth, and varies with 

 the various stages of the developement and decay of 

 their organs; some general idea of its influence may 

 have been gained from circumstances already mention- 

 ed: I shall now refer to it more particularly, and endea- 

 vour to connect it with a general view of the progress 

 of vegetation. 



If a healthy seed be moistened and exposed to 

 air at a temperature not below 45, it soon germinates; 

 it shoots forth a plume which rises upwards, and a 

 radicle which descends. 



If the air be confined, it is found that in the pro- 

 cess of germination the oxygene, or a part of it is ab- 

 sorbed. The azote remains unaltered; no carbonic 

 acid is taken away from the air, on the contrary some 

 is added. 



Seeds are incapable of germinating, except when 

 oxygene is present. In the exhausted receiver of the 



