§ 85. “Modern Alchemy” 117 § 86. X-Rays and Becquerel Rays 117 § 87. The Discovery of Radium 118 § 88. Chemical Properties of Radium 119 § 89. The Radioactivity of Radium 120 § 90. The Disintegration of the Radium Atom 122 § 91. “Induced Radioactivity” 123 § 92. Properties of Uranium and Thorium 123 § 93. The Radium Emanation 124 § 94. The Production of Helium from Emanation 125 § 95. Nature of this Change 127 § 96. Is this Change a true Transmutation? 128 § 97. The Production of Neon from Emanation 130 § 98. Ramsay’s Experiments on Copper 132 § 99. Further Experiments on Radium and Copper 134 § 100. Ramsay’s Experiments on Thorium and allied Metals 134 § 101. The Possibility of Making Gold 136 § 102. The Significance of “Allotropy” 136 § 103. Conclusion 142 LIST OF PLATES PLATE 1. Portrait of Paracelsus _Frontispiece_ TO FACE PAGE PLATE 2. Symbolical Illustration representing the Trinity of Body, Soul and Spirit 15 PLATE 3. Symbolical Illustrations representing-- (A) The Fertility of the Earth } 26 (B) The Amalgamation of Mercury and Gold } PLATE 4. Symbolical Illustrations representing-- (A) The Coction of Gold-Amalgam in a Closed Vessel } 33 (B) The Transmutation of the Metals } PLATE 5. Alchemistic Apparatus-- (A) (B) Two forms of apparatus for sublimation 37 PLATE 6. Alchemistic Apparatus-- (A) An Athanor } 38 (B) A Pelican } PLATE 7. Portrait of Albertus Magnus 44 PLATE 8. Portraits of-- (A) Thomas Aquinas } 52 (B) Nicolas Flamel } PLATE 9. Portraits of-- (A) Edward Kelley } 68 (B) John Dee } PLATE 10. Portrait of Michael Maier 72 PLATE 11. Portrait of Jacob Boehme 74 PLATE 12. Portraits of J. B. and F. M. van Helmont 76 PLATE 13. Portrait of J. F. Helvetius 84 PLATE 14. Portrait of “Cagliostro” 92 PLATE 15. Portrait of Robert Boyle 94 PLATE 16. Portrait of John Dalton 100