187 
by such elevation as well ashy the distance at which it happens 
to be situated from the ecjuator. Hence it is evident that plants 
will not always be found hardy or tender in proportion as they 
are natives of a more northern or southern latitude. It is 
therefore chiefly on the experience of tliemselves or their prede- 
cessors that cultivators depend for a knowledge of the hardihood 
of any plant under their care. 
Plants which we consider as belonging to the Greenhouse 
require a higher temperature to bring them to perfection than 
is usually present in this country ; but this increased temper- 
ature is in general obtained simply by an inclosed building of 
glass, which admits and confines the heat of the sun’s rays with- 
out permitting it to be dissipated by wind or cold air. Artificial 
heat, produced by fire, is required only in winter, and then only 
to keep the temperature of the house above the freezing point, 
or to dissipate the damp which may collect therein, from the 
evaporation continually going on from the plants and moist soil, 
which in winter the more readily becomes condensed, from the 
coldness of the glass and walls. 
“ 7’he plants should be looked over most days to see if any 
require water, w hich must only be given when quite dry ; in the 
winter season ; from nine to twelve o’clock in the morning is the 
best time for watering them, for, if watered in the afternoon, 
they are apt to be chilled at night, which makes their leaves 
look yellow and unhealthy. When the surface of the mould is 
green with moss, &c., the top should be taken off, and the 
surface moved with a flat stick, but not deep enough to disturb 
the roots; if a little fresh mould is wanted on any of them, it 
should be added, always being careful to put the same kind of 
soil they are already grown in, for we have seen a dift’erent kind 
])ut on sometimes, which injures plants more than some cul- 
tivators are aware of. When the weather begins to get warm 
in spring, a little air should be admitted all night, to harden the 
plants before they are set out, a little must be given at first, and 
continue to increase it till they have full air, if the weather will 
allow of it. The time of setting them out in the open air depends 
entirely on the weather. Sometimes they may be put out with 
safety by the middle of May, in other seasons not till the latter 
end; but they had better stay in a little too long, than be jjut 
out too soon. Calm cloudy weather is the best for setting them 
194 AOCTiEICM. 
