affinities; but we cannot, as matters stand, be sure of this. The things, in fact, he deals with have been already emptied of all life and peculiarity of their own: they are alike in quality, only differing by a more or less,--a difference which at any moment may be altered by an act of subtraction or addition. No doubt you can build up what are _called_ systems--compounds of a kind--in this way: but they do not really hang and grow together; they are only prevented from breaking up by the absence of any empty place to which the parts may withdraw. Bit holds up bit; but how all the bits have found themselves so caged up without exit is a mystery. Absolute neutrality or indifference of each part to others, and yet absolute equilibrium[1] in the total composite,--such is the situation. The chemical method (taking chemistry as a type of the sciences like optics, electricity, &c.) is a revelation of a different state of affairs. The elements of things are here seen to be unique and incomparable; yet in each there is a latent sympathy ready to break out when the proper occasion arrives. Bring two things together, and their affinity suddenly, in the proper circumstances, leads to their complete fusion: a product arises which, when formed, hardly betrays its origin and composition. In a way this is the converse of the mechanical or mathematical method. In it was no fusion, no inner mixture: each part after composition lay beside the other, and their union was only in the ideas of the onlooker. It was mere juxtaposition still,--though now closer: an abnormally keen eye would still have been able to descry the dividing lines and measure the gaps. At least mere mechanical physics tends so to conceive it. Here, on the contrary, there is union--but only at the moment of fusion: once that is accomplished, the result is apparently simple, and bears no suggestion of being a compound. In the mechanical union the result is exactly equal to the sum of the elements which go to make it: in the chemical there is something positively new, something, i. e., of which the premises gave no indication and made no promise.