[42] Stewart and Tait _on the Heating of a Disk by Rotation_ in vacuo (_Proceedings of the Royal Society_). See also Stewart’s _Elementary Treatise on Heat_, 3d edition, Art. 387 (Clarendon Press Series). [43] If the visible universe be imagined to be infinite, we should have (following out our line of thought) infinitely large masses separated from each other by infinite distances, appearing for infinite ages in the liquid and solid states, and thence transformed by means of infinite collisions into the gaseous condition in which they will remain for another infinite series of ages. Is there much gained by this conception? [44] i. 641. Thus rendered by Munro:—‘For fools admire and like all things the more which they perceive to be concealed under involved language, and determine things to be true which can prettily tickle the ears and are varnished over with finely sounding phrase.’ [45] This has been spoken of as an exaggeration. We hope it may be so; but when it was written (in the winter of 1874) the newspapers were full of the sickening details of the gouging of an old man by a gang of miners, who afterwards filled the sockets with quicklime! These human fiends are probably already at liberty, having had their few months of simple imprisonment! [46] Tait, _Proc. R.S.E._, 1874-5. [47] See also the extremely interesting article _Atom_, by Clerk-Maxwell, in the 9th ed. of the _Encyclopædia Britannica_. [48] Here it is important to observe that the speculations of Sir W. Thomson with regard to the density of the Ether assign only the inferior limit of that density. The _real_ density may possibly be very much greater. [49] _Études d’Astronomie Stellaire_, 1847. [50] In Art. 148 we made a suggestion that gravitation might be the visible result of a tendency to a minimum of some affection of the fluid in which atoms are immersed. The exertion of gravitating force might thus be associated with a change in the constitution of visible things, and might perhaps point to an ultimate dying out, just as the radiation from the sun, which obeys the same formal law as that of gravity, points to a dying out of our luminary. If this be conceivable, the really trivial nature of gravitating force (Art. 139) might come to be associated with the extraordinary persistence of the present state of things. [51] The words ‘left to its own laws’ must not be taken too literally. We ought perhaps rather to say, the procedure of the Governor of the visible universe is at present such as to indicate uniformity of physical laws, while, on the other hand, His procedure when producing the universe indicated an intelligent agent designing uniformity of product. [52] _Lay Sermons, Essays, and Reviews._ [53] Stewart on the _Conservation of Energy_. [54] Stewart on the _Conservation of Energy_. [55] Stewart on the _Conservation of Energy_. [56] See Meldrum on the _Periodicity of Rainfall_. [57] _Principles of Science_, vol. ii. p. 455.