331 
ven off by the operation of the same causes, and 
nearly in the same manner as it is afforded by ina- 
nimate bodies. By this carbon the surrounding oxy- 
gen is changed, and the development of the seed 
succeeds to this chemical action. In the progress of 
this development, the organization of the seed is un- 
folded ; and when this is sufficiently complete, the 
emission of carbon, like the other functions of the 
seed, is then executed by an organised structure, and 
becomes obedient to those laws which .govern and 
regulate the actions of living beings. It is the same 
with regard to moisture. The dried seed imbibes 
moisture, at first, like any other inanimate body. 
By this moisture, in conjunction with other agents, 
its organic structure is gradually developed, where- 
by a vascular system is evolved, and then properly 
commences the function of absorption. Hence, 
therefore, as it may be said that seeds, at first, sim- 
ply imbibe and afterwards absorb moisture, so do we 
say that the carbon at first is afforded by them as it 
is by inanimate matter ; but subsequently it passes 
off through an organic structure, when ic may pro- 
perly be said to be excreted or exhaled. 
642. In support of the doctrine, that the carbon of 
vegetables passes off in combination with their ex- 
haled fluids, we farther maintained (139.), that the 
changes in the air were most extensively effected, 
when plants possessed the greatest vigour, and the 
motion of their fluids was most actively carried on. 
On the contrary, whatever arrested the motion of 
these fluids, diminished the extent of the changes in 
the air, and consequently bore witness to a diminish- 
