I should be driven to suspicion of that cloud." And now, just as I say this, there actually comes a cloud into view. This cloud is the seeming impossibility of reconciling my truth, irradiation, with my truth, equability of diffusion. I say now:—"Behind this seeming impossibility is to be found what I desire." I do not say "real impossibility;" for invincible faith in my truths assures me that it is a mere difficulty after all; but I go on to say, with unflinching confidence, that, when this difficulty shall be solved, we shall find, wrapped up in the process of solution, the key to the secret at which we aim. Moreover—I feel that we shall discover but one possible solution of the difficulty; this for the reason that, were there two, one would be supererogatory—would be fruitless—would be empty—would contain no key—since no duplicate key can be needed to any secret of Nature.
And now, let us see:—Our usual notions of irradiation—in fact, all our distinct notions of it—are caught merely from the process as we see it exemplified in Light. Here there is a continuous outpouring of ray-streams, and with a force which we have at least no right to suppose varies at all. Now, in any such irradiation as this—continuous and of unvarying force—the regions nearer the centre must inevitably be always more crowded with the irradiated matter than the regions more remote. But I have assumed no such irradiation as this. I assumed no continuous irradiation; and for the simple reason that such an assumption would have involved, first, the necessity of entertaining a conception which I have shown no man can entertain, and which (as I will more fully explain hereafter) all observation of the firmament refutes—the conception of the absolute infinity of the Universe of stars—and would have involved, secondly, the impossibility of understanding a rëaction—that is, gravitation—as existing now—since, while an act is continued, no rëaction, of course, can take place. My assumption, then, or rather my inevitable deduction from just premises,—was that of a determinate irradiation—one finally discontinued.
Let me now describe the sole possible mode in which it is conceivable that matter could have been diffused through space so as to fulfil the conditions at once of irradiation and of generally equable distribution.
