I can now, for the first time, give to my opinions that degree of intelligibility, which is requisite for their introduction as hypotheses; the experiments above related, understood as in the common mode of thinking, prove that the magnetic influence flows in length, the electric fluid by suffusion, and that chemical agency (whatever the main agent may be) is qualitative and _in intimis_. Now my hypothesis demands the converse of all this. I affirm that a power, acting exclusively in length, is (wherever it be found) _magnetism_; that a power which acts _both_ in length and in breadth, and _only_ in length and breadth, is (wherever it be found) _electricity_; and finally, that a power which, together with length and breadth, includes depth likewise, is (wherever it be found) _constructive agency_. That is but _one_ phenomenon of magnetism, to which we have appropriated and confined the term magnetism; because of all the natural bodies at present known, iron, and one or two of its nearest relatives in the family of hard yet coherent metals, are the only ones, in which all the conditions are collected, under which alone the magnetic agency can appear in and during the act itself. When, therefore, I affirm the power of reproduction in organized bodies to be magnetism, I must be understood to mean that this power, as it exists in the magnet, and which we there (to use a strong phrase) catch in the very act, is to the same kind of power, working as reproductive, what the root is to the cube of that root. We no more confound the force in the compass needle with that of reproduction, than a man can be said to confound his liver with a lichen, because he affirms that both of them grow.