The men of science ridicule them because in so many cases the facts are imperfectly authenticated, and because in others the action of the powers is uncertain, dependent on conditions imperfectly ascertained, and not of that material kind to which material science willingly submits.

But if they be facts, if they relate to any element of human nature, all these things can be systematically investigated, the true separated from the false, the proven from the unproven.

The powers can be investigated, their conditions of action laid down.

Probably they may be so developed as to be exercised with comparative certainty, whether by every one or only by those special constitutions in which they may inhere.

Such investigations will at present only enlist the attention and care of a few qualified persons, and, that they may be carried on in peace and safety, should be carried on in secrecy.