It is exceedingly gratifying to me that a second edition of this book should be called for. But still more welcome is the change 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 and 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 Ramsay thought he had obtained evidence for the transmutation of hydrogen into helium by the action of the electric discharge, and Professors Collie and Patterson 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; and since the death of the latter, little, if anything, appears to have been done to settle the questions raised by his experiments. Reference must, however, be made to a very interesting investigation by Sir Ernest Rutherford on the “Collision of α-Particles with Light Atoms,” from which it appears certain that when bombarded with the swiftly-moving α-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, 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.