8. Nevertheless, there are persons who say : "You, on your side, admit that a
spirit can raise a table and retain it in space; is not that contrary to one of nature's laws,
viz., the law of gravitation?" Yes, contrary to that law as commonly understood; but do
you suppose that nature has revealed to us all its secrets? Before experiment had shown
us the ascensional force of certain gases, who could have imagined that a heavy
machine, bearing several men, could triumph over the force of attraction, and would not
the assertion of such a possibility have appeared incredible? If a man had proposed, a
century ago, to send a despatch five hundred leagues, and to receive an answer to it, in
the course of a few minutes, he would have passed for a madman; if he had done it, he
would have been declared to have the devil at his beck and call, for, in those days, it
was only the devil who could travel so quickly. Why, then, may there not be some
fluid, as yet unknown to us, possessing the property, under certain circumstances, of
counterbalancing the action of density, as hydrogen counterbalances the weight of a
balloon? This suggestion, we would remark in passing, is only a comparison, and not
an assimilation, arid is brought forward solely to show, by analogy, that the fact
assumed is not physically impossible. It is, in truth, precisely when the learned, in their
observation of these phenomena, have endeavoured to proceed by the road of
assimilation, that they have gone astray. In reality, the fact exists, and all tile negation
in the world cannot get rid of it, for denying is not disproving; in our eyes, there is
nothing supernatural about it, and this is all we have to say of it for the present.
