244 TREES AND TREE-PLANTING. 
mitted to the belief that she has provided in each section 
a growth of the drugs best suited to the relief of the 
diseases peculiar to that section, we nevertheless be- 
lieve, as the result of no little attention to the subject, 
that there are indigenous drugs much better suited to 
many of the diseases of this country than are some of 
the remedies of foreign extraction, the use of which med- 
ical fashion has perpetuated since their original introduc- 
tion. 
There are, moreover, but few of the foreign trees from 
which we derive our medicines which either do not at- 
tain to considerable perfection in the natural state in this 
country, or which may not be successfully cultivated in 
some section of our vast territory—in some of its valleys, 
on some of its mountain-sides, or along some of its water- 
courses. The actual and possible medicinal wealth of 
the United States of America is imperfectly appreciated 
even by medical men. Of late years more attention than 
heretofore has been directed to our indigenous medicinal 
flora, and the additions from this source to the materia 
medica have been of such a nature as to encourage and 
stimulate further research in this direction. 
In the consideration which we purpose giving the trees 
of this country which furnish substances employed in 
medicine we shall not confine ourselves strictly to our 
indigenous flora, nor to such trees as may be regarded 
as forest-trees. Some valuable trees have been intro- 
duced, and, though they have become naturalized and ac- 
climated, are not strictly entitled to be classed as natives. 
Some of our flora, too, which are rich in medicinal prin- 
ciples, are not of sufficient size to justify their classifica- 
tion among the forest-trees, that is, in the general ac- 
ceptation of the term. 
In this consideration of trees from a medicinal point 
of view we shall make no attempt at classification. The 
difficulties in the way of a perfect classification of drugs 
are insuperable, and are recognized as such by both phy- 
