Page:Scientific Monthly, volume 14.djvu/562

 His later ideas as to the nature of these physical lines of force are perhaps most fully explained in a letter to Richard Phillips, Esq., written in May, 1846, and published in Experimental Researches, III., p. 447. Some extracts from this letter are given below.

Again, in Experimental Researches II, p. 291, Faraday presents his theory of the nature of matter in much the same manner as above. At the conclusion of this discussion, he says:

We see from the above that Faraday's later electrical theory was based upon a concept of the nature of matter which is no longer regarded as tenable, but which necessarily profoundly modified his views on electrical phenomena. It did away at once with all distinction between matter and the ether, unless those parts of space in which the centers of force were less numerous than in other parts could be regarded as a separate medium. Any question as to the number of electrical fluids, or whether there was any electrical fluid at all, could have little significance. The atoms of bodies were merely centers from which innumerable contractile filaments which he called lines of force radiated in all directions and throughout all space. From his reasoning, these filaments