various metallic and other bodies; the means of affecting it by heat or cold; the way in which conducting bodies by combination enter into the constitution of non-conducting substances, and the contrary; and the actual existence of one elementary body, carbon, both in the conducting and non-conducting state. The power of electric conduction (being a transmission of force equal in velocity to that of light) appears to be tied up in and dependent upon the properties of the matter, and is, as it were, existent in them.
I suppose we may compare together the matter of the ether and ordinary matter (as, for instance, the copper of the wire through which the electricity is conducted), and consider them as alike in their essential constitution; i. e. either as both composed of little nuclei, considered in the abstract as matter, and of force or power associated with these nuclei, or else both consisting of mere centres of force, according to Boscovich's theory and the view put forth in my speculation; for there is no reason to assume that the nuclei are more requisite in the one case than in the other. It is true that the copper gravitates and the ether does not, and that therefore the copper is ponder able and the ether is not; but that cannot indicate the presence of nuclei in the copper more than in the ether, for of all the powers of matter gravitation is the one in which the force extends to the greatest possible distance from the supposed nucleus, being iniinite in relation to the size of the latter, and reducing that nucleus to a mere centre of force. The smallest atom of matter on the earth acts directly on the smallest atom of matter in the sun, though they are 95,000,000 of miles apart; tilrther, atoms, which, to our knowledge, are at least nineteen times that distance, and indeed, in cometary masses, far more, are in a similar way tied together by the lines of force extending from and belonging to each. What is there in the condition of the particles of the supposed ether, if there be even only one such particle between us and the sun, that can in subtilty and extent compare to this?
Let us not be confused by the ponderability and gravitation of heavy matter, as if they proved the presence of the abstract nuclei; these are due not to the nuclei, if they exist at all, but to the force super added to them; and, if the ether particles be without this force, which according to the assumption is the case, then they are more material, in the abstract
