348 Knowledge of the JVaiural Sciences. 
might be adduced of the benefits conferred by botany upon agri- 
culture. While science dictates such valuable improvements as 
those, the mere observation of trifling facts often suggests useful 
ideas. It is said that the occasional natural union of boughs of 
distinct trees, demonstrated the practicability of grafting, and that 
the observation of the circumstance of a vine shooting more 
vigorously after a goat had browsed on it, suggested the valuable 
art of pruning fruit trees. One of the Emperors of China having 
noticed that a particular stalk in his garden produced better rice 
than the rest, cultivated it for several years; and then having 
fully satisfied himself and his subjects of its superiority, he dis- 
tributed its grains among them for their general benefit. A far- 
mer having remarked that some gooseberry bushes, growing under 
an elder tree, were exempt from caterpillars, was induced to try 
the eflficacy of a decoction of elder leaves in destroying the grubs 
that infested his turnip crops, and he and other farmers who re- 
peated the experiment found it successful. 
It is not only necessary that the agriculturist should be well 
acquainted with the nature of the different vegetables which he 
cultivates for economical purposes, but that he should rightly 
understand the causes of the several ravages and diseases to which 
they are subject, so that he may be able to devise proper remedies 
and preventions. In nine cases out of ten, the failure of crops 
and the pecuniary losses experienced thereby, arise from the 
attack of some particular species of destructive insect, which, 
from unknown causes, has appeared in unusually great numbers. 
Before any effectual steps can be taken against it, it is absolutely 
necessary to ascertain correctly what species of insect is causing 
the mischief, and to study the creature's habits in all its transform- 
ations; for what will prove more or less effectual in one stage of 
its existence, will be totally useless, or perhaps, increase the evil 
in another. Notwithstanding the immense annual losses which 
must be caused by the millions of destructive insects that infest 
all kinds of crops, the science of entomology is comparatively 
neglected by agriculturists, who are, therefore, frequently unable 
to give a definite description of any noxious insect to a naturalist, 
when they enquire his opinion and advice. 
Those husbandmen who have possessed some knowledge of 
natural history, have not merely been better able to cultivate 
their plants and protect them from the attack of hurtful creatures, 
but they have ascertained thereby what creatures are harmless 
and useful, and therefore to be spared and encouraged. Without 
this power of discrimination, they may be unwittingly led into 
the error of destroying creatures which were absolutely beneficial 
to them. 
Natural history in its most extended sense, being inseparably 
