lement, to find what
compounds it forms with other elements; or, the spots on the sun--have
they any influence upon our weather?

Here, if the given cause be under control, as a new element may be, it
is possible to try experiments with it according to the Canons of
Inductive Proof. The inquirer may form some hypothesis or expectation as
to the effects, to guide his observation of them, but will be careful
not to hold his expectation so confidently as to falsify his observation
of what actually happens.

But if the cause be, like the sun-spots, not under control, the inquirer
will watch on all sides what events follow their appearance and
development; he must watch for consequences of the new cause he is
studying in many different circumstances, that his observations may
satisfy the canons of proof. But he will also resort for guidance to
deduction; arguing from the nature of the cause, if anything is known of
its nature, what consequences may be expected, and comparing the results
of this deduction with any consequent which he suspects to be connected
with the cause. And if the results of deduction and observation agree,
he will still consider whether the facts observed may not be due to some
other cause.

A cause, however, may be under control and yet be too dangerous to
experiment with; such as the effects of a poison--though, if too
dangerous to experiment with upon man, it may be tried upon animals; or
such as a proposed change of the constitution by legislation; or even
some minor Act of Parliament, for altering the Poor Law, or regulating
the hours of labour. Here the first step must be deductive. We must ask
what consequences are to be expected from the nature of the change
(comparing it with similar changes), and from the laws of the special
circumstances in which it is to operate? And sometimes we may partially
verify our deduction by trying experiments upon a small scale or in a
mild form. There are conflicting deductions as to the probable effect of
giving Home Rule to Ireland; and experiments have been made in more or
less similar cases, as in the Colonies and in some foreign countries. As
to the proposal to make eight hours the legal limit of a day's labour in
all trades, we have all tried to forecast the consequences of this; and
by way of verification we might begin with nine hours; or we might
induce some other country to try the experiment first. Still, no
verification by experiments on a small scal