212. Now, in the experiments on germination al- 
ready related (8. 9.), the gradual disappearance of 
oxygen and production of carbonic acid seem suffi- 
ciently to establish their conversion into each other ; 
and the stationary bulk which the residual air main- 
tained, after all the oxygen was consumed, together 
with the equality of volume between the above-named 
gases, appear, likewise, to prove that none of this acid 
gas was furnished by the seed alone. If the seed, in its 
germination, had furnished both the elements of car- 
bonic acid, then, as in its decomposition, the whole 
bulk of air employed ought to have been increased, 
which was not the case ; neither, on such a supposi- 
tion, are we able to assign any probable reason why 
the production of acid should, for a time, have cea- 
sed at the precise period,,when all the oxygen was con- 
sumed. We are, therefore, inclined to suppose a 
period, more or less long, to intervene between the 
formation of carbonic acid, during the growth of the 
seed, when oxygen gas is present, and its production 
by the same body, when the whole of that gas is con- 
sumed ; between that process which announces the 
evolution, and that which indicates the decomposi- 
tion of the seed. 
213. Should it, however, be objected to our ex- 
periments, that the process of decomposition may in- 
stantly follow the termination of living action, and 
thus confound the results, this objection will not ap- 
ply to the experiments of M. de Saussure, who ana- 
lyzed the residual air at intermediate periods of the 
process, and always found the quantity of carbonic 
acid formed, and of oxygen gas remaining, to make 
