9. For, (and this is the last step which I shall mention in this long series of ascending steps of multitude apparently infinite,) it now begins to be suspected that not some nebulæ only, but _all_, are resolvable into separate stars. When the nebulæ were first carefully studied, it was supposed that they consisted, as they appeared to consist, of some diffused and incoherent matter, not of definite and limited masses. It was conceived that they were not stars, but Stellar Matter in the course of formation into stars; and it was conceived, further, that by the gradual concentration of such matter, whirling round its centre while it concentrated, not only stars, that is, suns, might be formed, but also systems of planets, circling round these suns; and thus this _Nebular Hypothesis_, as it has been termed, gave a kind of theory of the origin and formation of systems, such as the solar system. But the great telescope which Lord Rosse has constructed, and which is much more powerful than any optical instrument yet fabricated, has been directed to many of the nebulæ, whose appearance had given rise to this theory; and the result has been, in a great number of cases, that the nebulæ are proved to consist entirely of distinct stars; and that the diffused nebulous appearance is discovered to have been an illusion, resulting from the accumulated light of a vast number of small stars near to each other. In this manner, we are led to regard every nebula, not as an imperfectly formed star or system, but as a vast multitude of stars, and, for aught we can tell, of systems; for the apparent smallness and nearness of these stars are, it is thought, mere results of the vast distance at which they are placed from us. And thus, perhaps, all the nebulæ are, what some of them seem certainly to be, so many vast armies of stars, each of which stars, we have reason to believe, is of the nature of our sun; and may have, and according to analogy has, an accompaniment of living creatures, such as our sun has, certainly on the earth, probably, it is thought, in the other planets. 10. It is difficult to grasp, in one view, the effect of the successive steps from number to number, from distance to distance, which we have thus been measuring over. We may, however, state them again briefly, in the way of enumeration.