IT is exceedingly gratifying to me that a second edition of this book should be called for. But still more welcome is thechange in the attitude of the educated world towards the old-time alchemists and their theories which has taken place during the past few years.

The theory of the origin of Alchemy put forward in Chapter I has led to considerable discussion; but whilst this theory has met with general acceptance, some of its earlier critics took it as implying far more than is actually the case. As a result of further research my conviction of its truth has become more fully confirmed, and in my recent work entitled Bygone Beliefs (Rider, 1920), under the title of "The Quest of the Philosopher's Stone," I have found it possible to adduce further evidence in this connection. At the same time, whilst I became increasingly convinced that the main alchemistic hypotheses were drawn from the domain of mystical theology and applied to physics and chemistry by way of analogy, it also became evident to me that the crude physiology of bygone ages and remnants of the old phallic faith formed a further subsidiary source of alchemistic theory. I have barely, if at all, touched on this matter in the present work; the reader who is interested will find it dealt with in some detail in "The Phallic Element in Alchemical Doctrine" in my Bygone Beliefs.

In view of recent research in the domain of Radioactivity and the consequent advance in knowledge that has resulted since this book was first published, I have carefully considered the advisability of rewriting the whole of the last chapter, but came to the conclusion that the time for this was not yet ripe, and that, apart from a few minor emendations, the chapter had better remain very much as it originally stood. My reason for this course was that, whilst considerably more is known to-day, than was the case in 1911, concerning the very complex transmutations undergone spontaneously by the radioactive elements--knowledge helping further to elucidate the problem of the constitution of the so-called "elements" of the chemist--the problem really cognate to my subject, namely that of effecting a transmutation of one element into another at will, remains in almost the same state of indeterminateness as in 1911. In 1913, Sir William Ramsay¹ thought he had obtained evidence for the transmutation of hydrogen into helium by the action of the electric discharge, and Professors Collie and Patterson² thought they had obtained evidence of the transmutation of hydrogen into neon by similar means. But these observations (as well as Sir William Ramsay's earlier transmutational experiments) failed to be satisfactorily confirmed;³ and since the death of the latter, little, if anything, appears to have been done to settle the question raised by his experiments. Reference must, however, be made to a very interesting investigation by Sir Ernest Rutherford on the "Collision of -Particles with Light Atoms,"⁴ from which it appears certain that when bombarded with the swiftly-moving -particles given off by radium-C, the atoms of nitrogen may be disintegrated, one of the products being hydrogen. The other product is possibly helium,⁵ though this has not been proved. In view of Rutherford's results a further repetition of Ramsay's experiments would certainly appear to be advisable.

As concerns the spontaneous transmutations undergone by the radioactive elements, the facts appear to indicate (or, at least, can be brought into some sort of order by supposing) the atom to consist of a central nucleus and an outer shell, as suggested by Sir Ernest Rutherford. The nucleus may be compared to the sun of a solar system. It is excessively small, but in it the mass of the atom is almost entirely concentrated. It is positively charged, the charge being neutralised by that of the free electrons which revolve like planets about it, and which by their orbits account for the volume of the atom. The atomic weight of the element depends upon the central sun; but the chemical properties of the element are determined by the number of electrons in the shell; this number is the same as that representing the position of the element in the periodic system. Radioactive change originates in the atomic nucleus. The expulsion of an -particle therefrom decreases the atomic weight by 4 units, necessitates (since the -particle carries two positive charges) the removal of two electrons from the shell in order to maintain electrical neutrality, and hence changes the chemical nature of the body, transmuting the element into one occupying a position two places to the left in the periodic system (for example, the change of radium into niton). But radioactivity sometimes results in the expulsion of a -particle from the nucleus. This results in the addition of an electron to the shell, and hence changes the chemical character of the element, transmuting it into one occupying a position one place to the right in the periodic system, but without altering its atomic weight. Consequently, the expulsion of one - and two -particles from the nucleus, whilst decreasing the atomic weight of the element by 4, leaves the number of electrons in the shell, and thus the chemical properties of the element, unaltered. These remarkable conclusions are amply borne out by the facts, and the discovery of elements (called "isobares") having the same atomic weight but different chemical properties, and of those (called "isotopes") having identical chemical characters but different atomic weights, must be regarded as one of the most significant and important discoveries of recent years. Some further reference to this theory will be found in § 77 and 81: the reader who wishes to follow the matter further should consult the fourth edition of Professor Frederick Soddy's The Interpretation of Radium (1920), and the two chapters on the subject in his Science and Life (1920), one of which is a popular exposition and the other a more technical one.

These advances in knowledge all point to the possibility of effecting transmutations at will, but so far attempts to achieve this, as I have already indicated, cannot be regarded as altogether satisfactory. Several methods of making gold, or rather elements chemically identical with gold, once the method of controlling radioactive change is discovered (as assuredly it will be) are suggested by Sir Ernest Rutherford's theory of the nuclear atom. Thus, the expulsion of two -particles from bismuth or one from thallium would yield the required result. Or lead could be converted into mercury by the expulsion of one -particle, and this into thallium by the expulsion of one -particle, yielding gold by the further expulsion of an -particle. But, as Professor Soddy remarks in his Science and Life just referred to, "if man ever achieves this further control over Nature, it is quite certain that the last thing he would want to do would be to turn lead or mercury into gold--for the sake of gold. The energy that would be liberated, if the control of these sub-atomic processes were as possible as is the control of ordinary chemical changes, such as combustion, would far exceed in importance and value the gold. Rather it would pay to transmute gold into silver or some base metal."

In § 101 of the book I suggest that the question of the effect on the world of finance of the discovery of an inexpensive method of transmuting base metal into gold on a large scale is one that should appeal to a novelist specially gifted with imagination. Since the words were first written a work has appeared in which something approximating to what was suggested has been attempted and very admirably achieved. My reference is to Mr. H. G. Wells's novel, The World Set Free, published in 1914.

In conclusion I should like to thank the very many reviewers who found so many good things to say concernig the first edition of this book. For kind assistance in reading the proofs of this edition my best thanks are due also and are hereby tendered to my wife, and my good friend Gerald Druce, Esq., M.Sc.

H. S. R.

191, CAMDEN ROAD, LONDON, N.W.1.
October 1921.

The basic idea permeating all the alchemistic theories appears to have been this: All the metals (and, indeed, all forms of matter) are one in origin, and are produced by an evolutionary process. The Soul of them all is one and the same; it is only the Soul that is permanent; the body or outward form, i.e., the mode of manifestation of the Soul, is transitory, and one form may be tranmuted into another. The similarity, indeed it might be said, the identity, between this view and the modern etheric theory of matter is at once apparent.

The old alchemists reached the above conclusion by a theoretical method, and attempted to demonstrate the validity of their theory by means of experiment; in which, it appears, they failed. Modern science, adopting the reverse process, for a time lost hold of the idea of the unity of the physical universe, to gain it once again by the experimental method. It was in the elaboration of this grand fundamental idea that Alchemy failed. If I were asked to contrast Alchemy with the chemical and physical science of the nineteenth century I would say that, whereas the latter abounded in a wealth of much accurate detail and much relative truth, it lacked philosophical depth and insight; whilst Alchemy, deficient in such accurate detail, was characterised by a greater degree of philosophical depth and insight; for the alchemists did grasp the fundamental truth of the Cosmos, although they distorted it and made it appear grotesque. The alchemists cast their theories in a mould entirely fantastic, even ridiculous--they drew unwarrantable analogies--and hence their views cannot be accepted in these days of modern science. But if we cannot approve of their theories in toto, we can nevertheless appreciate the fundamental ideas at the root of them. And it is primarily with the object of pointing out this similarity between these ancient ideas regarding the physical universe and the latest products of scientific thought, that this book has been written.

It is a regrettable fact that the majority of works dealing with the subject of Alchemy take a one-sided point of view. The chemists generally take a purely physical view of the subject, and instead of trying to understand its mystical language, often (I do not say always) prefer to label it nonsense and the alchemist a fool. On the other hand, the mystics, in many cases, take a purely transcendental view of the subject, forgetting the fact that the alchemists were, for the most part, concerned with operations of a physical nature. For a proper understanding of Alchemy, as I hope to make plain in the first chapter of this work, a synthesis of both points of view is essential; and, since these two aspects are so intimately and essentially connected with one another, this is necessary even when, as in the following work, one is concerned primarily with the physical, rather than the purely mystical, aspect of the subject.

Now, the author of this book may lay claim to being a humble student of both Chemistry and what may be generalised under the terms Mysticism and Transcendentalism; and he hopes that this perhaps rather unusual combination of studies has enabled him to take a broad-minded view of the theories of the alchemists, and to adopt a sympathetic attitude towards them.

With regard to the illustrations, the author must express his thanks to the authorities of the British Museum for permission to photograph engraved portraits and illustrations from old works in the British Museum Collections, and to G. H. Gabb, Esq., F.C.S., for permission to photograph engraved portraits in his possession.

The author's heartiest thanks are also due to Frank E. Weston, Esq., B.Sc., F.C.S., and W. G. Llewellyn, Esq., for their kind help in reading the proofs, &c.

H. S. R.

THE POLYTECHNIC, LONDON, W.
October, 1910.

§ 1. Alchemy is generally understood to have been that art whose end was the transmutation of the so-called base metals into gold by means of an ill-defined something called the Philosopher's Stone; but even from a purely physical standpoint, this is a somewhat superficial view. Alchemy was both a philosophy and an experimental science, and the transmutation of the metals was its end only in that this would give the final proof of the alchemistic hypotheses; in other words, Alchemy, considered from the physical standpoint, was the attempt to demonstrate experimentally on the material plane the validity of a certain philosophical view of the Cosmos. We see the genuine scientific spirit in the saying of one of the alchemists: "Would to God . . . all men might become adepts in our Art--for then gold, the great idol of mankind, would lose its value, and we should prize it only for its scientific teaching."⁶ Unfortunately, however, not many alchemists came up to this ideal; and for the majority of them, Alchemy did mean merely the possibility of making gold cheaply and gaining untold wealth.

¹ See his "The Presence of Helium in the Gas from the Interior of an X-Ray Bulb," Journal of the Chemical Society, vol. ciii. (1913), pp. 264 et seq.

² See their "The Presence of Neon in Hydrogen after the Passage of the Electric Discharge through the latter at Low Pressures," ibid., pp. 419 et seq.; and "The Production of Neon and Helium by the Electric Discharge," Proceedings of the Royal Society, A, vol. xci. (1915), pp. 30 et seq.

³ See especially the report of negative experiments by Mr. A. C. G. Egerton, published in Proceedings of the Royal Society, A, vol. xci. (1915), pp. 180 et seq.

⁴ See the Philosophical Magazine for June, 1919, 6th Series, vol. xxxvii. pp. 537-587.

⁵ Or perhaps an isotope of helium (see below).

⁶ "EIRENÆUS PHILALETHES": An Open Entrance to the Closed Palace of the King (see The Hermetic Museum, Restored and Enlarged, edited by A. E. Waite, 1893, vol. ii. p. 178).