186 GREEN-HOUSE. [January. 
GREEN-HOUSE. 
JANUARY. 
Tins compartment requires particular attention, in order 
to preserve the plants in good health, and carry them through 
this precarious season of the year. A little air must be ad- 
mitted at all convenient times. An hour or two at mid-day 
will be of the utmost importance in drying up damp and 
clearing off stagnated air, which is a harbour for every corrup- 
tion. The top sashes being let down or turned a few inches, 
in mild days (that is, when there are not high and cutting 
winds), from ten or eleven o'clock to two or three, according 
to the intensity of the frost, will renovate the interior air of 
the house and harden the plants. When the weather will 
permit, let the front sashes be opened about one inch or 
more. An assiduous, experienced hand will never omit an 
opportunity. 
With regard to fire heat, the temperature must be regu- 
lated to suit the nature of the plants in a general sense ; so 
let the mercury, or spirits of wine, of Fahrenheit's thermo- 
meter, be from 35° to 50° f if it begins to fall, give a little 
fire heat. No doubt we have seen the thermometer much 
lower in the green-house than the above, even as low as 24° 
without any immediate injury; but it was in an extensive 
collection, where the most hardy of the plants were selected 
into one house. Many boast how little tire they give their 
green-house, and how cold it is kept, not observing the 
miserable state of their plants — inexperience causing them to 
think that the least fire heat will make them grow, and 
would rather look on naked stems than healthy plants. The 
above temperature will not, in exotics, cause premature vege- 
tation, but will cause the plants to retain the foliage requisite 
to vegetative nature. A high temperature is not necessary 
for the generality of green-house plants; on the contrary, it 
might very much injure them. 
