Chemistry has ascertained that the heat of the earth is far greater than any tract of the heavens through which it passes; that this heat could not have been communicated by the sun's rays, for had it been so the surface would be hotter than the interior, the very reverse of which is found to be the fact, and the deeper we go down the higher the temperature is. Chemistry shows further that this heat can be completely accounted for by the condensation and solidification of the earth itself; for the condensation of all gases into liquids, and of liquids into solids, causes a very large portion of latent caloric to become sensible, for example, any quantity of a gas at 60 deg. suddenly reduced to a smaller bulk, would have a temperature higher than 60 deg. A little contrivance has long been in use for obtaining fire by this process, consisting of a cylinder and piston, the rod of which if struck down sets fire to a piece of German-tinder. It is probable that all fire, and every alteration of temperature, are due to this one cause alone. Now assuming it as a fact that the earth was once in a gaseous state, and that the atoms of this gas or vapour exerted (as they must have done) an attraction towards each other, the result would be that they would press immensely upon those parts towards the centre and cause them to solidify. This act of solidification would produce such an intense heat that the solid would be expanded and fused into a liquid, this continuing until all the more condensible matters had become liquid, the earth would assume its spheroidal form from its rotation, be surrounded by an atmosphere of the least easily condensible substance, nitrogen, together with all the oxygen not wanted to combine with the metallic vapour and form earth. This globe with its atmosphere continuing to roll through the cold regions of space, would gradually lose the heat from its outer part by radiation. A film of cooled and condensed earthy matter would begin to form on the surface by crystallisation, and then would commence all those grand phenomena which it is the province of the geologist to study and explain. This crust consisted of the first-formed granite which (from inequality of contraction in the bulk of the earth) was broken up into fragments and perhaps partly re-dissolved again and again in some places, as it chanced that these contractions were more or less irregular. The result of this crushing and crumbling-up is seen in the coarser parts of the gneiss, called "Grauwacke," which consist of angular fragments of granite more or less imbedded in a cement of the same substance. This could not have been produced by water, as the surface must have been too hot for it to have existed on the earth in any other form than the most highly rarefied steam combined with the atmosphere, and in all probability partly condensed in the upper regions, forming a continuous strata of clouds, or rather water, through which the sun could hardly