something like this will also be the case when Mr. Darwin's magnum opus makes its appearance.

66

But these analogies as to the history merely of these two theories, however close, are of less consequence than the analogy that obtains respecting the groundwork and basis of the theories. "Is gravitation [Mr. Warington asks] a real cause capable by its action of controlling planetary motion? i. e., is the hypothesis possible?" And so, he also asks, "Is Mr. Darwin's hypothesis possible?—Are the elements involved in it real elements capable of producing the kind of effects he ascribes to them?" I am sure, he will see, that I am giving his argument every possible advantage in thus keeping it constantly in juxtaposition with his chosen instance and the most popular science of modern times. And I will admit that just as we all know that a stone or an apple falls to the ground by its weight, and that therefore, so far, gravitation is a real cause; so we are all positively quite aware that "the kind of effects " Mr. Darwin lays stress upon, are certainly produced by climate, use and disuse, by growth with reproduction and inheritance, and by the external conditions of life and the consequent struggles for existence among plants and animals. I never heard of a man that denied an apple would fall to the ground; and I cannot conceive how those who believe in the unity of the human species can possibly deny against the evidence of their own eyes, that mankind at least have diverged and developed marvellously in all directions away from the original type of Adam and Eve, whatever we may consider their type to have been. But it is one thing to admit that an apple falls, and another to conclude that the moon, which does not fall, is under the same influence. So, it is one thing to admit that all mankind have descended from a common stock, and quite another therefore to conclude that man has descended from the same common stock as goats and monkeys. But, now, it is here that the analogy halts. Granted the first and second laws of motion, as propounded by Stevinus and accepted in the Principia, and granted that gravitation is a constant force; it is perfectly possible-and I think perfectly easy-to demonstrate whether or not a gravitating body could revolve round a centre of attraction without ever falling -that is, to prove or disprove the possibility of gravitation as a real cause capable of controlling planetary motion;—but I am not aware of any attempt to do this by Sir Isaac Newton or any of his followers. I say the possibility of universal gravitation might thus be tested by mathematical demonstration; but I do not in the least see how Darwinism ever can be. It would be unreasonable to require that it should be

established by such a test,-as unreasonable, I humbly think, as it was in the other case to dispense with such a test.

I therefore pass over the test of possibility as applied to Darwinism, to apply the other tests of harmoniousness, consistency and adequacy. And again, I must revert to the analogy of what Mr. Warington thinks established the adequacy of gravitation, the discovery of the planet Neptune,-and which I will venture to say is strictly analogous to what was supposed to be the discovery of "the missing link between man and apes" in the famous Neanderthal skull, appealed to so confidently in the Antiquity of Man by Sir Charles Lyell, and in Man's Place in Nature by Professor Huxley. Again, I think the analogy will be found to run admirably on all fours. I am glad to follow Mr. Warington in his chosen analogies, and I am doing my best to complete them in thorough detail. Mr. Warington appears to have taken his view of the discovery of Neptune from Sir John Herschel's Outlines of Astronomy. But he ought to know that Messrs. Peirce and Gould, the American astronomers, have written also on the subject. From Mr. Gould's Report on the History of the Discovery, published in Washington in 1850, it appears that the tables used for the computations of the places of Uranus were calculated by M. Bouvard in 1821, and are now known not to represent the places of that planet, which was observed twenty times between 1690 and 1771, but was then mistaken for a fixed star. I cannot, however, here pursue the whole history of the discovery of Neptune. It is enough to say that certain irregularities or perturbations in the observed motions of Uranus led to the idea (which was shared by M. Bouvard himself) that these were caused by the influence of some exterior planet. Without going into the question of priority of discovery between Mr. Adams and M. Le Verrier, I shall here give you their respective computations of the mass, eccentricity, mean distance, period of revolution, and longitude of perihelion, of the supposed exterior planet, in a tabular form, alongside the figures deduced by Messrs. Walker and Peirce from actual observation of the planet Neptune after it was discovered. Thus :

The mass, it will be observed, of M. Le Verrier, is more than twice, that of Mr. Adams nearly three times, the true one. The planet's actual distance falls short of its theoretical distance by about 500 millions of miles; its period of revolution is fifty years shorter; its eccentricity is only one-twelfth of the theoretical planet; and its longitude of perihelion in 1847 was only 47°, instead of 285° or 299°. The discrepancy as to the planet's heliocentric longitude I do not go into, as it would occupy too much time; and I think I have shown enough (all of which is probably new to Mr. Warington) to prove to him and all present, that the discovery of Neptune is not such a perfect confirmation of the certainty of the Newtonian hypothesis as he believes.* I must entirely object to bolstering up one theory in science by credulous appeals to other sciences, without investigation. It reminds me forcibly of the way in which idol-worship, that grossest of human absurdities, was maintained in its day, as described by the prophet Isaiah.†

But I must do Mr. Warington the justice to say, that in appealing to astronomy he only follows in the wake of Mr. Darwin himself, and of Professor Huxley and Dr. Büchner. But I doubt whether any of those Darwinians who thus make appeals to astronomy have paid much attention to that science. I am sure Mr. Warington is too candid not to make a frank admission, or to put me right, on this point as regards himself. But he must forgive me, if I am wrong; for I think I have good reason to come to this conclusion, when I find him saying in his paper, that "it would be impossible and absurd to discuss the motions of the fixed stars with the definition given that the fixed stars are those which never move," as if he were unaware that it is precisely on that assumption that the theory of "solar motion in space" was propounded by the first Herschel, and till recently had been the conclusion come to by all astronomers. But Mr. Warington goes boldly beyond most people in his mode of "sticking up," if I may so say, for the astronomy of the day. Even if Neptune had not been discovered, his faith would not have been shaken, however perturbed the planet Uranus might be. He is quite prepared to assume that the perturbations might be caused by some invisible body; and, of course, upon that hypothesis, the planets may move as erratically as they please, and we may always have an invisible, but quite conceivable cause, to explain the whole matter! Upon this system of theorizing, it is quite

* Vide Discovery of the Planet Neptune. By J. Von Gumpach; in loc. + Is. xli. 7. Airy's Lectures on Astr., 4th ed., p. 173. Vide, also, Journ. of Trans. of Vict. Inst., vol. i., p. 27.

ridiculous to take the trouble to discover new planets! But surely this is proving or assuming too much; and certainly, if we may reason thus, the discovery of Neptune was supererogatory! Apparently, Mr. Warington is not aware that there have been other hitches about gravitation; and that M. Le Verrier some time ago, in order to keep the solar system in gear upon the Newtonian hypothesis, was obliged to have recourse to this same mode of proof, and to invent an invisible "ring of asteroids between the sun and Mercury, the aggre gate mass of which was comparable to that of Mercury; and another ring of asteroids near the earth equal to a tenth of the earth's mass," &c. I quote this from Mr. Hind's letter to The Times of 17th September, 1863. And I must further remind Mr. Warington of another discovery, made by our own astronomer, Mr. Adams, namely, that his predecessors had all omitted, in computing "the acceleration of the moon's mean motion," to allow for the effect of the sun's disturbing force when acting in the direction of a tangent to the moon's orbit. An account of this is given in Lord Wrottesley's address, as President of the British Association at Oxford, in June, 1860. On this point there were three great mathematicians, Adams, Airy, and the late Sir John Lubbock, on one side, with three equally distinguished names, MM. Plana, Pontécoulant, and Hansen, on the other; and strangely enough it is admitted by the English mathematicians, and by Lord Wrottesley, while they declare Mr. Adams to be right, that all the calculations come out more accurately when the sun's influence upon the moon is omitted, which it certainly ought not to have been, if the moon is subject to the sun's attraction! *

It is, however, notwithstanding such facts as these, that Mr. Warington makes his appeal to universal gravitation; and that Mr. Darwin says, "there is grandeur in this view of life with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning, endless forms, most beautiful and most wonderful, have been, and are being evolved." + And so, Professor Huxley, in Man's Place in Nature, is "fully convinced that, if not precisely true, Mr. Darwin's hypothesis is as near an approximation to the truth, as, for instance, the Copernican hypothesis was to the true theory of the planetary motions." Lastly, Dr. Büchner, as a frankly avowed atheist, gives us this extraordinary opening to his chapter on Primeval Generation :-"There was a time when the earth—a fiery globe + Orig. of Species, p. 525.

* Vide Current Phys. Astr., in loc. (Hardwicke.)

*

-was not merely incapable of producing living beings, but was hostile to the existence of vegetable and animal organisms." But afterwards, "with the appearance of water," he tells us, "organic life developed itself"! Then at Nottingham last year, in Mr. Grove's address, while we had much the same sentiments repeated as to "the self-evolving powers of nature," and the doctrine of continuity, we had actually gravitation questioned, although Mr. Warington has once more made this appeal to the discovery of Neptune as proving the truth of the theory, I very much fear without going into the merits of that discovery. And just so was a confident appeal made by Sir Charles Lyell and Professor Huxley to the discovery of the Neanderthal skull, as an evidence that there probably was some low-caste, half-human creature, intermediate between man and apes (which, of course, there might have been without proving transmutation from the one into the other); but upon investigation by Dr. Barnard Davis, it was found that the Neanderthal skull proved nothing, being evidently an abnormal development, caused by synostysis or ossification of the sutures, and that similar skulls, known to be the skulls of modern men, are in our museums.

Dismissing, then, Mr. Warington's chosen analogy as worthless, I come to his direct arguments in favour of Darwinism. Mr. Warington, I think, very fairly states one of the main issues thus:-"That species grow and reproduce, and that they pass on their characteristics by inheritance, and that they are liable to variation is admitted by every one. The point at issue is whether they can so pass on and accumulate their variations' by inheritance as in the end to bring about specific differences," i.e. new species. Of course it is obvious that, in order to settle this point, we must have a definite meaning for the word "species." Well, Sir, I think I can furnish a meaning that, although somewhat absolute, will not be questioned, at least by Mr. Warington, namely this:-"The only fair definition of a species is a race of living beings possessing common characteristic differences from all others, which differences at the present time are constant and inherent." This definition is Mr. Warington's own! occurs just before the other quotation I have made from his paper. It is admitted that at the present time the characteristics of species are constant and inherent. Yet, according to the same authority, if species are liable to such variation as may accumulate and in the end bring about new species, then Darwinism is to be pronounced "possible"! But, as

* Force and Matter, p. 63. (Trübner & Co.)

It