An argument against the hypothesis of central heat has been stated by an ingenious author as carrying with it the evidence of demonstration.
“The essential and characteristic property of the power producing heat, is its tendency to exist every where in a state of equilibrium, and it cannot hence be preserved without loss or without diffusion, in an accumulated state. In the theory of Hutton, the existence of an intense local heat, acting for a long period of time, is assumed. But it is impossible to procure caloric in an insulated state. Waving every objection to its production, and supposing it to be generated to any extent, it cannot be continued, but must be propagated to the contiguous matter. If a heat, therefore, existed in the central region of the earth, it must be diffused over the whole mass; nor can any arrangement effectually counteract this diffusion. It may take place slowly, but it must always continue progressive, and must be utterly subversive of that system of indefinitely renewed operations which is represented as the grand excellence of the Huttonian Theory. Again, he observes, in giving what he says appears to him a demonstration of the fallacy of the first principles of the Huttonian System, it will not be disputed, that the tendency of caloric is to diffuse itself over matter, till a common temperature is established. Nor will it probably be denied, that a power constantly diffusing itself from the centre of any mass of matter, cannot remain for an indefinite time locally accumulated in that mass, but must at length become equal or nearly so over the whole.