II 
of experiments made on the growth of seeds in oxy- 
gen gas. For a few days, the volume of gas, in 
these experiments, diminished, and the oxygen was 
more or less completely changed into carbonic acid : 
hence it is inferred that oxygen gas is absorbed by 
seeds, and this to the amount, in some cases, of one- 
third of the whole gas employed *. To these expe- 
riments many objections occur ; for, in the first 
place, pure oxygen is not the gas in which seeds na- 
turally grow, and no such diminution of volume at- 
tends their ordinary germination in atmospheric air. 
Moreover, a mere diminution is no proof of the ab- 
sorption of oxygen, in the physiological sense of that 
term; for, in Mr Acton's experiments, paste and 
other inanimate substances produced a similar dimi- 
nution of oxygen, although no living power could 
then have been exerted. On the other hand, this 
diminution, when it does happen, appears to be acci- 
dental ; for in the experiments of Scheele and Cruick- 
shank (6.) no sensible change of volume seems to 
have attended germination, even in oxygen gas. 
These experiments, therefore, are not only excep- 
tionable in themselves, but are contradicted by others, 
and by the results of germination in atmospheric air. 
They are farther objectionable from not distinguish- 
ing between the operations of living and inanimate 
matter ; and, were it even allowed that oxygen was 
absorbed in these experiments, such a concession 
would not prove that it is equally absorbed in atmos- 
pheric air, where the process is in all respects natural, 
and the results are altogether different. 
* Nicholson's Journal, vol. xxiii. p. 22p. 
