The series of phenomena we have supposed to arise admit of an explanation free of the hypothesis of motion, and we avoid the dangerous ground of metaphysical speculation, and the subtleties of that logic which rests upon the immateriality of all creation. This explanation, it is freely admitted, is incomplete: we cannot distinctly correlate each feature of the phenomena, combine link to link, and thus form a perfect chain; but it is sufficiently clear to exhibit what we do know, and leave the unknown free for unbiassed investigation. Each particle, each atom of that which conveys to our senses the only ideas we have of natural objects--ponderable matter--is involved in, or interpenetrated by, those principles which we call heat and electricity, with probably many others which are unknown to us; and although these principles or powers are, according to some law, bound in statical equilibrium to inert matter, they are freely developed by an external excitement, and the disturbance of any one of them, upsetting the equilibrium, leaves the other power equally free to be brought under the cognizance of human sense by their effects. When we come to an examination of the influences exerted by these powers upon the physical earth, the position, that they must be regarded as the causes of motion rather than the effects of it, will be further considered. At present it is only necessary to state thus generally the views we entertain of the conditions of matter in connection with the imponderable forces and mechanical powers. The conversion, as it has been called, of motion into heat, in the experiments of Count Rumford and Mr. Joule,[12] are only evidences that a certain uniformity exists between the mechanical force applied, and the amount of heat liberated. It does not appear that we have any proof of the conversion of motion into physical power. It is necessary, to a satisfactory contemplation of the wonderful properties of matter, and of the forces regulating the forms of the entire creation, that we should be content with regarding the elementary bodies which chemistry instructs us form our globe, as tangible, ponderable atoms, having specific and distinguishing properties. That we should, as far as it is possible for finite minds to do so, endeavour to conceive the powers or forces--gravitation, molecular attraction, electricity, heat, light, and the principle which determines all chemical phenomena--as manifestations of agencies which hold a place between the most subtile form of matter and the hidden principles of vitality, which is still vastly inferior to the spiritual state, which reveals itself dimly in psychological phenomena, and arrives at its sublimity in the God of the universe. FOOTNOTES: