67 
uriance in the vegetation of North and South America vthich 
is unequalled by any other portion of the globe. And as one 
extremity of the United States is influenced by the severity 
of polar cold and the other powerfully affected by equa¬ 
torial heat, while the far greater part, as already remarked, 
is found under temperate latitudes, we should expect what 
we know to be the fact, that the variety of our plants would 
be peculiarly great. But that we may the more clearly dis¬ 
cover the advantages enjoyed in the United States for the 
study and improvement of Botany, allow me to present you 
with a sketch, a little more distinct, of the face of the coun~ 
try, and of its soil and climate; with a cursory notice of 
some of the plants already known. 
That vast chain of mountains which extends in a north 
and south direction, across the United States, is the most 
striking feature of the country. This great ridge is inter¬ 
sected by many others, which, though comparatively small? 
are, when separately taken, by no means inconsiderable.— 
These mountains are generally of the primitive formation. 
The rivers which descend from these mountains, are an¬ 
other striking characteristic. The St. Lawrence, the Hud¬ 
son, the Susquehanna, Ohio, and Missisippi; whether we 
consider the length of their course, or the quantity of their 
water, may vie with any in the old world. 
Our lakes are no less conspicuous and peculiar than our 
rivers and mountains. Huron and Superior, Ontario and 
Erie, are without rivals, and almost without resemblance, 
in any other part of the globe. 
Now it is to be remembered that the banks of rivers, the 
bases of mountains, and the margin of lakes, are always 
sought after by the Botanist, as particularly favorable to his 
researches. 
The soil at the base of our mountains towards the Atlan¬ 
tic, is generally composed of a rich mould, from two to four 
feet in depth. Nearer the ocean a clay soil, mixed with 
loom seems to predominate.* 
* Bush’s Medical Enquiries and Observations—also Proud’s Histo¬ 
ry of Pennsylvania. 
