fessor Clerk Maxwell at the Bradford meeting of the British Association in 1873

'No theory of evolution can be formed to account for the similarity of molecules, for evolution necessarily implies continuous change, and the molecule is incapable of growth or decay, of generation or destruction. None of the processes of nature, since the time when nature began, have produced the slightest difference in the properties of any molecule. We are therefore unable to ascribe either the existence of the molecules, or the identity of their properties, to the operation of any of the causes which we call natural. On the other hand the exact equality of each molecule to all others of the same kind, gives it, as Sir John Herschel has well said, the essential character of a manufactured article, and precludes the idea of its being eternal and self-existent. Thus we have been led along a strictly scientific path very near to the point at which science must stop. Not that science is debarred from studying the internal mechanism of a molecule which she cannot take to pieces, any more than investigating an organism which she cannot put together. But in tracing back the history of matter science is arrested when she assures herself on the one hand that the molecule has been made, and on the other that it has not been made by any of the processes which we call natural.

Science is incompetent to reason upon the creation of matter itself out of nothing. We have reached the utmost limit of our thinking faculties when we have admitted that, because matter cannot be eternal and self-existent, it must have been created. It is only when we contemplate not matter in itself, but the form in which it actually exists, that our mind finds something on which it can lay hold. That matter as such should have any fundamental properties, that it should exist in space and be capable of motion, that its motion should be persistent, and so on, are truths which may, for anything that we know, be of the kind which metaphysicians call necessary. We may use may use our knowledge of such truths for purposes of deduction, but we have no data for speculating as to their origin. But that there should be exactly so much matter, and no more, in every molecule of hydrogen, is a fact of a very different order. We have here a particular distribution of matter, a collocation-to use the expression of Dr. Chalmers-of things which we have no difficulty in imagining to have been arranged otherwise. The form and dimensions of the orbits of the planets, for instance, are not determined by any law of nature, but depend upon a particular collocation of matter. The same is the case with respect to the size of the earth, from which the standard of what is called the metrical system has

been derived. But these astronomical and terrestrial magnitudes are far inferior in scientific importance to that most fundamental of all standards, which forms the base of the molecular system. Natural causes, as we know, are at work which tend to modify, if they do not destroy, all the arrangements and the dimensions of the earth, and the whole solar system. But though in the course of ages catastrophes have occurred, and may yet occur, in the heavens, though ancient systems may be destroyed, and new systems evolved out of their ruins, the molecules out of which these systems are built, the foundation-stones of the material Universe, remain unbroken and unworn. They continue this day as they were created, perfect in number and measure and weight, and from the ineffaceable character impressed on them we may learn that those aspirations after accuracy in measurement, truth in statement, and justice in action, which we reckon amongst our noblest attributes as men, are ours because they are essential constituents of the image of Him who in the beginning created not only the heaven and the earth, but also the materials of which heaven and earth consist.'

Here we have an argument for an intelligent and moral first cause which may, if I understand it rightly, be stated thus. The atoms of the primary substances of matter have a character which

suggests the work of a designing will. They are like 'manufactured articles.' This character, I presume, is seen in the similarity of the atoms of the same primary substance to one another, and in the affinities of the atoms of different substances for one another. Hence ultimately their capacity to build up the Universe.

This special character of theirs was essential at least to much of the order, arrangement, adaptation, and mechanism which we see in the natural world. And indeed, apart from its potentially involving much of the present character of the Universe, we are also to see in it, considered by itself, an evidence that there is in the Divine mind something corresponding to our desire of accuracy in measurement, truth in statement, and justice in action." But it is not a character which they could have acquired by any evolution, for they are primitive and unchangeable. Natural selection, which may have done much to accomplish the wonders of animal mechanism, has no place here, for the things concerned have always been the same, so far as we can tell, through all the revolutions of nature. Hence it is reasonable to attribute that special character to the immediate appointment of a Creator who foresaw its results.

The following question arises. If it be granted that with our present knowledge we can point to no natural agency that would modify or produce the cha

racter of an atom, are we therefore justified in saying that no such agency ever existed? Because we do not know the natural cause of any phenomenon-nay, if you will, cannot conjecture how it could have had a natural cause at all-is it safe at once to pronounce it supernatural ?

The atoms of the primary substances cannot, it is true, at present be resolved by chemists. But it has been at least plausibly conjectured that they might be composed of still more elementary atoms.1 Dr. Prout put forth such a conjecture. His particular theory that they were composed of atoms in different combinations, each the half in weight of a hydrogen atom, has not perhaps been sufficiently verified so far. But there are resemblances among the atoms of certain of the primary substances which give encouragement to the idea of a common origin or composition. And of late Mr. Lockyer, arguing from Father Secchi's observations on the spectra of different stars, has given support to the idea, that what are in our experience atoms of different elementary substances, may be resolved, under intense heat, into, some more elementary form of matter.2 These facts of course make for the idea that the chemically indissoluble atom, as we know it, is not a primitive form of matter, but a result of some process.

'See 'The Unseen Universe,' chap. v.

2 Address of M. Wurtz, No. of Nature' for August 27, 1874.