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THE FLORIST’S JOURNAL. 
stances, should be beneficial to vegetation rather than detri¬ 
mental ; and it can only be in cases where gross mismanagement 
of some kind or other exists, that they can be productive of any 
injury or inconvenience. 
While such considerations as these seem to point out that 
the admission of air to any great extent to forcing-houses, at 
a very early part of the season, is not on good grounds a 
matter of urgency, and that at any rate the influx of large 
volumes of cold air is decidedly hurtful at that time of the year, 
yet the other extreme must not be fallen into, for the process 
may not altogether be dispensed with. It does appear, ne¬ 
vertheless, that the regulation of the temperature, — the pre¬ 
vention of too powerful a degree of heat, when the source of 
that heat is the sun, — is the great end to be effected by the 
practice. If there are any other real advantages, they are cer¬ 
tain to follow, if air is admitted for this purpose alone; and 
these advantages, if any there are, are not likely to be lost, if 
air is not admitted, when it is not necessary to do so with this 
primary purpose in view. Periods of bright sunshine, then, 
may be regarded as the only instances in which a recourse to 
the practice is absolutely necessary. 
From all this the conclusion at which I have arrived is, that 
with a proper system and routine of management, as regards 
atmospheric humidity and temperature, the admission of large 
volumes of the external air to the interior of forcing-houses is 
not politic, nor by any means so essential as it is generally 
represented to be. Whatever other difference of opinion may 
exist with respect to this point of practice, it cannot be denied 
that a risk is incurred, and frequently an injury sustained, when 
cold air comes in contact with the tender organs of forced 
plants, at an early part of the season ; and therefore, if no other 
advantage than the regulation of the temperature is derived 
from the practice, then, except in cases when the internal heat 
is increased by the influence of the sun, and therefore uncon¬ 
trollable, it would be a wiser course to apply a less amount by 
artificial means, thus rendering it less necessary to allow the 
superabundant portion to escape, and exposing the plants in a 
less degree to the risk already alluded to. 
Even in those cases in which it is really necessary to have 
recourse to the practice, much injury may be sustained by 
admitting it in a rash and improper manner. It should be so 
