the circuit which we have especially in view; if we wish to reduce this motive force of the circuit to the unit of surface, we must divide that expression by the magnitude of the section .
With respect to the causal relation between the law of electric attractions and repulsions, and that of the diffusion of electricity, or respecting the mutual dependence of the functions and on each other, we will, for the present, not enter into any further inquiries, as shortly an occasion will present itself for this purpose. We will here content ourselves with the observation, that the above mode of explanation has arisen from the endeavour to render the similarity of the mode of treatment in the doctrines of electricity and heat very obvious.
31. Without pursuing any further these conditions to an external change of place of the parts of a galvanic circuit, let us now turn to those changes in the qualitative state of the circuit which are produced by the electric current, i. e. in the internal relation of the parts to each other, and which derive their explanation from the electro-chemical theory of bodies. According to this theory, compound bodies must be considered as a union of constituents which possess dissimilar electric states; or, in other words, dissimilar electroscopic force. But this electroscopic force, quiescent in the constituents of the bodies, differs from that to which our attention has hitherto been directed, inasmuch as it is linked to the nature of the elements, and cannot pass from one to the other, without the entire mode of existence of the parts of the body being destroyed. If we confine ourselves, therefore, in the following considerations, to the case where changes, it is true, occur in the quantitative relation of the constituents, and where consequently chemical changes of the body, composed of these constituents, also occur, but where the constituents themselves undergo no alteration destroying their nature, we are able to show the validity of all the laws above developed of electric bodies with reference to their reciprocal attraction and repulsion, only the transition of the electricity from one particle to the other entirely disappears in the consideration of chemically different constituents. A distinction here exists with reference to electricity exactly similar to that which we are accustomed to define relative to heat, by calling it sometimes latent, sometimes free heat. For the sake of brevity, we will in like manner term that electroscopic force
