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EFFECTS OF SITUATION AND EXPOSURE 
These errors are occasioned either by a want of experience respecting 
the constitution of the plant, or from inattention to the extreme 
change of temperature to which it is exposed in its new place, or from 
ignorance that situation and exposure change the constitution of 
plants to such a degree that, while one is perfectly hardy if nursed on 
a northern aspect, another of the same kind shall be so tender and vul¬ 
nerable on a southern exposure, that it dies, or is cut down to the 
ground, under the slightest frost. 
Want of experience concerning the constitution of a newly imported 
plant may be said to be an excusable want of judgment; because 
we have no means of knowing without experience, there being no 
general rule to guide. If, indeed, we are told that it is an annual from 
a warm country, we may safely conclude that it will succeed in this 
climate during summer, as many tropical annuals do. Or, if it be a 
perennial herb from the same country, we may find it answer with us 
if it be only protected from frost. But if tropical shrubs or trees are 
brought to us, we cannot, from any external mark, judge whether they 
are liable to be killed by frost or not. If they shed their leaves 
in winter, it is only a sign that they are winter-resting plants, not that 
they are hardy; because there are several tropical plants which are 
deciduous, as for instance, the silk cotton tree (JBombax ceiba ); and 
many evergreens are as hardy as those that shed their leaves. 
We often fail in preserving tender plants from inattention to local 
circumstances. We are liable to mistake shelter for warmth. Frost 
and the north and east winds are most dreaded in this country. A 
southern exposure, whether for the abode of animals, or a station 
for vegetables, is always considered the most eligible, merely, perhaps, 
because it is the most agreeable to our own perceptions. But in respect 
of vegetables we often err in this matter, both in choosing sheltered 
situations and southern exposures. 
Cold (or rather cold air) is always most intense in humid situations, 
because there is the most copious evaporation. Such situations, in this 
country, are either on the tops of clayey hills, or in the lowest valleys, 
where there is either a lake, river, or brook. These low grounds are 
nearer the main springs, and often abound with them, whence 
exhalations are ever rising, though imperceptible ; of course such a 
valley must always be more chilly, and more subject to keen frost than 
any drier or more elevated situation. Such glens, provided they are 
open to the south, are chosen as the most suitable for tender exotics, 
merely because they are more sheltered from the northern blast. In 
the summer, indeed, such a locality is most favourable to the quick 
and strong growth of every plant. The air, being generally calm and 
