cyanide of potassium, of nickel, phosphorus, the common acids, and a
multitude of other substances, has led to the employment of a whole
army of workmen in the conversion of those substances into articles
of utility. The foregoing examples might be greatly enlarged upon,
and a great many others might be selected from the sciences of
physics and chemistry: but those mentioned will suffice. There is
not a force of Nature, nor scarcely a material substance that we
employ, which has not been the subject of several, and in some cases
of numerous, original experimental researches, many of which have
resulted, in a greater or less degree, in increasing the employment
for workmen and others." {1}

"All this may be very true. But of what practical use will physical
science be to me?"

Let me ask in return: Are none of you going to emigrate? If you
have courage and wisdom, emigrate you will, some of you, instead of
stopping here to scramble over each other's backs for the scraps,
like black-beetles in a kitchen. And if you emigrate, you will soon
find out, if you have eyes and common sense, that the vegetable
wealth of the world is no more exhausted than its mineral wealth.
Exhausted? Not half of it--I believe not a tenth of it--is yet
known. Could I show you the wealth which I have seen in a single
Tropic island, not sixty miles square--precious timbers, gums,
fruits, what not, enough to give employment and wealth to thousands
and tens of thousands, wasting for want of being known and worked--
then you would see what a man who emigrates may do, by a little sound
knowledge of botany alone.

And if not. Suppose that any one of you, learning a little sound