347 
were chiefly of a physiological nature ; and although 
they do not seem to have drawn much attention 
from others, yet to ourselves they have always ap- 
peared to approach nearly to perfect demonstration. 
They were derived chiefly from the " Memoirs on Re- 
spiration" by the late Abbe Spallanzani, and the con- 
tinuation of this writer's labours enables us to add 
some facts in addition to those already stated (142.), 
in farther confirmation of this doctrine. Whatever 
difference of opinion may prevail as to the state in 
which the carbon exists, and the mode in which it is 
expelled from the body, we must think the follow* 
ing facts afford decisive evidence of the immediate de- 
pendence of this action upon the living powers of the 
animal system. 
653. It has been already remarked (1.) that seeds, 
in a perfectly dry state, do not, in the smallest de* 
gree, affect the quality of the air in which they are 
confined ; and such, too, we may conclude, must bfc 
the case with the rotifer (48.) and various other 
zoophytes, which, when rendered perfectly dry, re- 
main unchanged for an indefinite period of time. 
654. The experiments already detailed (142.) suf- 
ficiently prove, that, during the suspension of living 
action in the vermes and mollusca classes, no change 
whatever is induced on the air that surrounds them. 
The correctness of these facts we have since verified 
by experiment ; for we found that snails, while con- 
fined in glass vessels over mercury, and kept in tern* 
peratures at or below the freezing point, remained 
quite torpid, and did not emit any sensible portion 
of fluid from their bodies, nor, in the smallest de- 
