100 
ladies’ flower gardener. 
prives the plant of certain properties necessary to its perfection, 
but not essential ^o its life. These differences in the processes by 
which oxygen gas is alternately consumed and evolved, during 
the vegetation of plants in sunshine, are so manifest, both in their 
nature and effects, as to satisfy the ascription of a name to th6 
latter process distinct from that given to the former. It might, 
perhaps, be denominated the chemical process, in contradistinc¬ 
tion to that named physiological. 
“ It would contribute much, we think, to simplify our inquiries 
concerning vegetation, to bear in mind these distinctions; to con¬ 
sider the one process as accomplished by the agency of the air, 
and essential to the life and growth of the plant; the other, as 
subordinate, depending on the agency of light, and though neces¬ 
sary to the perfection of vegetation, yet not essential to its exist¬ 
ence. In this manner each process may be followed out sepa¬ 
rately, both in regard to its immediate effects and remoter con¬ 
sequences, without clashing with the other; and the apparently 
discordant and even contradictory phenomena which on a first 
view they seem to exhibit, may be reconciled, and considered, not 
less in theory than in fact, as conspiring together to form one 
harmonious and perfect wnole.” 
After these explanations, little need be added respecting the 
supply of pure air to domestic greenhouses. The deterioration 
of the atmosphere in the case is daily counteracted by an oppo¬ 
site process of purification, so that amidst the vicissitudes of per¬ 
petual change, the air is maintained in a state of nearly uniform 
composition and purity, and serves over and over again for all the 
purposes of vegetation. It may, however, be stated, to prevent 
misconception, that the more pure the air of the apartment, the 
plants will have the better chance of thriving, because there must 
necessarily be an interchange to some extent betwixt the air of 
the room and the case, in consequence of the daily expansion 
