In Practice, Antichristian. 335 that sentiment abounding among men which causes 'each to 'esteem other better than themselves.' The glory of the Church and its beneficent commission are to undo the heavy 'burdens, to break every yoke, and let the oppressed go free.' The working men of England need such mental liberation, and the foremost to demand it for them ought to be the Church, for which our workmen's predecessors raised those 'sacred' buildings which are still the pride of Christendom, the glory of our land. When this is undertaken, all the eloquence of modern churchmen about art as ministering to religion' will spontaneously cease. The clergy will remember that the Founder of their church and their religion was 'as he that 'serveth;' that He came, not to be ministered unto, but to 'minister; and then, discerning that the excellence of Christianity is in its own loving servitude, they will abandon the idea that 'art' can ever be 'the handmaid of religion,' or that it has a ministry to fulfil in the religious life of man.' Their more sensibly-directed aim will be to make religion, in its boundless sympathy and wise benevolence, a minister to art. Thus they will cordially recognise the individual working man, and help to gain for him his ancient social dignity and mental freedom; so that, restored to reasoning intelligence, to imaginative power, and to artistic self-control, he may again become, as once he was, and always was designed to be, 'a vessel unto honour, sanctified and meet for the Master's service, and prepared unto every good work.' ART. II.-The Atomic Theory of Lucretius CONTRASTED WITH MODERN THEORIES OF ATOMS, THE CONSTITU- (1.) Lucretius: De Rerum Natura. Books I. and II. (3.) Molecules: A Lecture delivered before the British Asso- (4.) The Mystery of Matter, and other Essays. By J. ALLANSON PICTON. Macmillan. 1873. (5.) The Atomic Theory of Lucretius. North British Review,' Vol. XLVIII. THE Roman poet Lucretius appears to have acquired at present a very strong interest for scientific men and others. His name has of late found frequent mention in reviews and magazines, even in sermons and newspapers. This unwonted popularity is not on account of his bold attempt to abolish the gods and give a deathblow to superstition, hardly caring, meanwhile, whether religion might perish at the same time. Nor is he read by all even for his splendid poetic genius, for some of his admirers are extremely unpoetic people. The true reason is that his poem contains an admirably clear and straightforward exposition of a scientific theory which is now very largely accepted, and which, in connection with Evolution, has gained a new and somewhat startling importance. The propositions in which Lucretius has stated his atomic theory anticipate some recent scientific discoveries in a most marvellous way. Indeed, the agreement makes us wonder how the ancient students of nature, who had no means of verifying the observations of the senses through experiment, could have succeeded as they did. Like men walking abroad at night without a lantern, they could take with them no test of experimental inquiry by which to verify their hypotheses; but, in spite of all, some faculty enabled them to keep the right path. And this is the more wonderful, because (like our modern wave-theory of light and colour) the atomic hypothesis, in some points, goes altogether contrary to the evidence of the senses. Certainly, it must have been thought startlingly original when first proposed, nor is it imagine what could have suggested to any man's conception which the senses seem so to contradict. points it illustrates the fertile insight of the Greek mind. But, while this theory is accepted as in great part true, Lucretius's deduction from it, the very thing for the sake of which he embraced it so eagerly, is completely false. Instead of the atoms being eternal-a mere assumption-so that the world could make itself, and the existence of a Creator be cut off, they enable us rather to infer from them a Creator, from whom their powers are derived. A famous scientific inquirer in the domain of molecular physics, in a late dis easy to mind a In these Present Popularity of Lucretius. 337 course, even infers from the character of the atoms and the exact collocation of matter' which they exhibit, the existence of a First Cause, their Maker. Things which are unalterable cannot, he argues, have been formed by any of the processes which we call natural, and since each molecule is exactly similar to all others of the same kind, they bear the character of manufactured articles,' not of that which is eternal and self-existent.* The poem on 'Nature,' De Rerum Natura, has an extraneous interest; it is of value for more than the thoughts of Lucretius. If the work of Epicurus, entitled 'Concerning Nature,' or the other, 'Concerning the Atoms and Void,' still existed, in which he set forth his theory of atoms, we should go to him as the older and more original source. Not that even he was its author: the germ of the theory is attributed to Leucippus. It was next taught by Democritus (sometimes called a pupil of Leucippus), who died about B.C. 350, and it was nearly a century later before it was fully developed by Epicurus. The works of the latter two are lost to us, and this most astonishing fruit of ancient thought, which has been adopted and substantiated by modern experimental science, is to be found fully described only in Lucretius's poem. He has followed Epicurus closely, as coincidences with the letters of Epicurus, preserved by Diogenes, make very plain. He has added perhaps nothing really new to the theory: his contribution to it is only a most eloquent and plain exposition of what he found in Epicurus. One great aim of Lucretius's poem was to set forth the scientific truth of the time, and its value in the eyes of science now lies in its full and exact statement of an ancient theory, which the latest experiments confirm. This it is which at present gives Lucretius so special an interest. The history of the Atomic theory in modern times is well known. The name of the chemist in whose hands it acquired *Clerk-Maxwell. But, according to Professor Clifford, we have no evidence as yet that the molecules of any given gas are exactly' of the same weight. Moreover, even if they were, we have no evidence that it is absolutely impossible for molecules of matter to have been evolved out of ether by natural processes. Besides the evolution of organised beings, resulting in a great number of forms, we can conceive, he says, other processes of evolution, resulting in a definite number of forms, such as the chemical elements. The First and the Last Catastrophe.' Fortnightly, April, 1875. a new force is now inseparably associated with it. Dalton assumed the existence of atoms, conjectured that the weight of the atoms making up each element is constant, assigned different specific weights to the different kinds of atoms, discovered the laws according to which they combine, and thus founded his celebrated Atomic Theory. So important were these discoveries and their results that Dalton has earned the title of the Father of Modern Chemistry.' The progress of chemical knowledge during the last century has been vitally connected with the hypothesis that there are such things as atoms, ultimate particles of matter, and its developments, nor is its value, as concerns fresh discovery, yet exhausted. In 1873 a well-known chemist, the President of the British Association, asked, in the course of his address, What is the 'meaning of the great activity shown at present in chemistry.' He answered the question thus: 'Chemists are examining the combining properties of atoms, and getting clearer views of 'the constitution of matter.' Some of our readers may be surprised to find how similar the atom, as described by Lucretius, is to the modern chemical atom. Professor Fleeming Jenkin, of Edinburgh, has gone over all Lucretius's statements in his First and Second Books as to the constitution of matter, and has shown that they are either certainly true, or else that they foreshadow the truth. Therefore the theory, as its old discoverers held it, has more than a mere historical interest. Professor Jenkin's article on The 'Atomic Theory of Lucretius' is both thorough and original; and in endeavouring to realise what Lucretius's theory of atoms was, and to understand how it enabled him to look upon nature and practically to grasp its force, the student is greatly aided by it. We shall go over Lucretius's propositions one by one, giving, at the same time, their modern equivalents, much as Professor Jenkin has done, also pointing out where we dissent from him, particularly with regard to the motion of the atoms. Professor Clerk-Maxwell's wonderful Lecture on 'Molecules,' in which he describes the modern atom, will also help us. Unscientific readers will remember at once with what a thrill of discovery they read it, and how they seemed to themselves to follow a daring guide far into the region of *In the North British Review,' vol. xlviii. He owns Epicurus for his Master. 339 the unknown. The views of modern science with regard to the process of Evolution, the origination of life, and the character of matter, as illustrated by Tyndall's presidential address, will enable us to realise more definitely, by comparison, what Lucretius's actual creed on these points was. Both Lucretius and Tyndall advocate Evolution: it is only to be expected that Tyndall's line of argument should be the more complete of the two. Before beginning to set forth his philosophy in due order, Lucretius expresses in the strongest way his obligations to his master: 'When human life lay shamefully grovelling upon earth, crushed down under the weight of Religion, who 'showed her face from heaven, frowning upon mortals from on 'high with awful aspect, a man of Greece was the first who ' ventured to lift mortal eyes to her face, and the first to with'stand her openly.' Neither stories of the gods nor the thunders of heaven could make him afraid, but rather spurred him on, says the poet, to burst the bars of nature and find her secret. 'Therefore the living force of his soul prevailed, and 'he passed out far beyond the flaming walls of the world,* and 'traversed in mind the boundless universe, whence he returns, 'a conqueror, to tell us what can be and what cannot be; in 'short, on what principle each thing has its properties defined and its deep-set boundary-mark. Wherefore religion is put "beneath our feet and trampled on in turn; us his victory raises 'to heaven.' 6 There is a boundless pity in the words describing the misery of men owing to the dominion of superstition-the same pity and enthusiasm for humanity that has made saints and philanthropists in all ages, from Saint Francis to Robert Owen (though, perhaps, there was more of the latter in the constitution of Lucretius). But we have quoted the passage to show what Epicurus was to Lucretius. Elsewhere he designates him a god; the popular deities, he says, are small compared with * What would Lucretius have said to the spectrum analysis, by which the chemist can literally pass beyond the 'flaming walls of the world' (that is, the fiery circuit of ether forming our heavens), and bring us tidings from the distant stars? Wonderful, indeed, he would have thought it; but he would have valued it most if it could have aided him in any way to prove that the gods have not created either the world or man, and are powerless whether for good or evil. |