equable degree of
moisture beneath and among the soil, as well as in the composition of the
atmosphere, can be secured with perfect ease, and a trifling amount of
labour.

CHAP. VII.

ON THE REGULATION OF THE TEMPERATURE.

If we figure to our minds, a plant which in its native habitat enjoys a
climate far more genial, and a temperature far more elevated, than our own
country affords, it must be obvious that some regulation, and increase of
temperature, either positively, by the artificial application of heat, or
negatively, by affording shelter and protection, will be required in order
to ensure any degree of success in its cultivation. The Cucumber is a
reputed native of the East, and we have therefore in this supposed fact,
an indication of the nature of the climate, which it should be our object
to provide for it; but still it must be borne in mind, that in conducting
any system of artificial cultivation, it is not at all times desirable, or
even safe, to supply a resemblance to any part of the natural
circumstances affecting the growth of a particular plant, unless we have
the means of supplying the _greater part_, or _all_ the conditions which
exist in a state of nature: this I shall again have occasion to refer to.

By another step we arrive at the conclusion that the standard of
temperature, to which the Cucumber is submitted in its cultivation in this
country, is a point, varying with the individual opinion of cultivators;
as some may take a part of the natural conditions of growth as their rule;
others, all these circumstances; and others, again, various combinations
of them.

Referring back again to the provisions of nature, we can scarcely hesitate
to conclude, that in clear sunny weather, the temperature to which the
Cucumber is submitted, _cannot within reasonable limits_, be permitted to
rise too high; whilst at other times, when the weather is dull, or cloudy,
and always at night, a much lower degree of heat ought to be applied. In
sunny weather, the natural agents which cause excitement and activity of
the vital functions, are in full action; and consequently at such periods
we may rationally indulge in the application of those exciting agents
which are under our controul--always however bearing in mind, that we must
not unduly apply one agent, when we either cannot, or neglect to apply the
others also. On the other hand, in dull weather, and at night, the source
of light being in the one c