The conclusions reached in the first part of this paper, while we were dealing only with gross visible matter, may have seemed bold enough; but they are far surpassed by the inference which our authors draw from the vortex theory as they interpret it. Our authors exhibit various reasons, more or less sound, for attributing to the primordial fluid some slight amount of friction; and in support of this view they adduce Le Sage's explanation of gravitation as a differential result of pressure, and Struve's theory of the partial absorption of light-rays by the ether,--questions with which our present purpose does not require us to meddle. Apart from such questions it is every way probable that the primary assumption of Helmholtz and Thomson is only an approximation to the truth. But if we accredit the primordial fluid with even an infinitesimal amount of friction, then we are required to conceive of the visible universe as developed from the invisible and as destined to return into the invisible. The vortex-atom, produced by infinitesimal friction operating through wellnigh infinite time, is to be ultimately abolished by the agency which produced it. In the words of our authors, "If the visible universe be developed from an invisible which is not a perfect fluid, then the argument deduced by Sir William Thomson in favour of the eternity of ordinary matter disappears, since this eternity depends upon the perfect fluidity of the invisible. In fine, if we suppose the material universe to be composed of a series of vortex-rings developed from an invisible universe which is not a perfect fluid, it will be ephemeral, just as the smoke-ring which we develop from air, or that which we develop from water, is ephemeral, the only difference being in duration, these lasting only for a few seconds, and the others it may be for billions of years." Thus, as our authors suppose that "the available energy of the visible universe will ultimately be appropriated by the invisible," they go on to imagine, "at least as a possibility, that the separate existence of the visible universe will share the same fate, so that we shall have no huge, useless, inert mass existing in after ages to remind the passer-by of a form of energy and a species of matter that is long since out of date and functionally effete. Why should not the universe bury its dead out of sight?"