landscape, or whether a man with good eyes is shut up in a dark room. It is of this the poet speaks, when he says:-
"O Lady! we receive but what we give,
And in our life alone does Nature live:
Ours is her welding-garment, ours her shroud !
And would we aught behold of higher worth,
Than that inanimate cold world allow'd
To the poor, loveless, ever-anxious crowd,
Ah! from the soul itself must issue forth
A light, a glory, a fair luminous cloud
Enveloping the earth;
And from the soul itself must there be sent
A sweet and potent voice, of its own birth,
Of all sweet sounds the life and element!"
But let us hasten to our friend Philosophus, who is a man of quite a different mould. Once, when he was young, his tutor said to him, "Have the goodness, sir, to solve the following problem: A hemispherical bowl is filled with a heavy fluid, the density of which varies as the 12th power of the depth below the surface; find the whole pressure and the resultant pressure on the semi-lune of the surface contained between two vertical planes passing through the centre of the bowl, and making with each other an angle 2" But Philosophus thrust the paper violently aside, saying "I will have none of that," and in fact was extremely rude. You may be sure, therefore, that when he came to be a man he had a mind of his own, and carried out his own ideas. He told us lately that he had been studying the laws of energy. It is a mistake, he said, to suppose that these laws are difficult of compre- hension; they are merely remote from our ordinary con- ceptions, and must be patiently pursued until you grasp them. He had studied them, he said, at all times and on all occasions in the railway carriage, on the thorough- fare, in the study, on his bed, in the night watches; and now that he had come to perceive their exceeding grandeur, and beauty, and simplicity, they were a source of great and continual joy to him, and recompensed him more than a thousandfold for all the trouble he had taken. Philosophus lately told us certain truths which may, perhaps, be of service to the readers of NATURE, Ile said that, not far from London, there was a place where the spirits and understandings of men were annually ground to pieces in a huge machine made of the very best metal; ay, such is its temper, said he, that were it only made into good broadswords, it might enable us to cleave our way to the very heart of the universe. Again, he said: "No doubt the dulness of science is a cry of the blind; nevertheless, men of science are much to blame. It is their sense of beauty that leads them to Truth, whom they discover by means of the glorious garments which she wears. But she is immediately stripped of these, and dressed in an antiquated medieval garb, worse than that of any charity-school girl, and equal to that of any Guy Faux: no wonder that in such guise her beauty is un- perceived by those who cannot pierce the veil, and that as a consequence she is slightly esteemed."
There was another thing he told us-a thing of the highest importance. The priests of Science," he said, must consent to use the vernacular, before they will ever make a profound impression upon the heart of humanity; and when they have learned to do this, let them not fear the sneers of their deacons who will call their teaching sensational.
F. R. S.
THE ATOMIC CONTROVERSY
IT is one of the most remarkable circumstances in the history of men, that they should in all times have sought the solution of human problems in the heavens rather than upon the earth. Sixty years ago a memorable instance of this truth occurred when Dalton borrowed from the stars an explanation of the fundamental pheno- mena of chemical combination. Carbon and oxygen unite in a certain proportion to form carbonic acid;" and this proportion is found to be invariable, no matter from what source the compound may have been prepared. But carbon and oxygen form one other combination, namely, "carbonic oxide"-the gas whose delicate blue flame we often see in our fires. Carbonic oxide may be obtained from many sources; but, like carbonic acid, its composition is always exactly the same. bodies, then, illustrate the law of Definite Proportions. But Dalton went a step further. Ile found that, for the same weight of carbon, the amount of oxygen in "carbonic acid" was double that which exists in carbonic oxide. Several similar instances were found of two elements forming compounds in which, while the weight of the one remained constant, the other doubled, trebled, or quad- rupled itself. Hence the law of Multiple Proportions. The question was-in fact, the question is-how to account for these laws. Dalton soon persuaded himself that matter was made up of very small particles or minima naturæ, not by any possibility to be reduced to a smaller magnitude. Matter could not be divisible without limit; there must be a barrier somewhere. No doubt, as a chemist, he would have rejected the famous couplet-
Big fleas have little fleas, upon their backs, to bite 'em;
And little fleas have smaller fleas, and so ad infinitum.
"Let the divisions be ever so minute," he said, "the number of particles must be finite; just as in a given space of the universe, the number of stars and plancts cannot be infinite. We might as well attempt to introduce a new planet into the solar system, or to annihilate one already in existence, as to create or destroy a particle of hydrogen." All substances, then, are composed of atoms; and these attract each other, but at the same time keep their distance, just as is the case with the heavenly bodies. The atoms of one compound do not resemble those of another in weight, or size, or mutually gravitating power. But as they are indivisible, it is between them that we must conceive all chemical action to take place; and an atom of any particular kind must always have the same weight. The atom of carbon weighs 5; the atom of oxygen weighs 7. Carbonic oxide, containing one of each must therefore be invariably constituted of 5 carbon, and 7 oxygen carbonic acid must in like manner contain 5 carbon, and 14 oxygen. Ilere, then, Dalton not only states that he has accounted for the two laws we have mentioned by making a single assumption; but he evidently intends his theory to be used as a criterion or control in all future analytical results, and already views it as the birth-place of chemical enterprise.
Such, and so great, was the atomic theory of Dalton; founded, certainly, on erroneous numbers, but containing in itself the germ of their correction; aspiring to the command in innumerable conquests; and setting itself for the rise or fall of the chemical spirit.
