emanation into neon, in presence of water, as indisputably proved, and, if a transmutation be defined as a transformation brought about at will, by change of conditions, then _this is the first case of transmutation of which conclusive evidence is put forward_.”[119] However, Professor Rutherford and Mr. Royds have been unable to confirm this result. They describe[120] attempts to obtain neon by the action of emanation on water. Out of five experiments no neon was obtained, save in one case in which a small air leak was discovered; and, since the authors find that very minute quantities of this gas are sufficient to give a clearly visible spectrum, they conclude that Ramsay’s positive results are due, after all, to leakage of air into the apparatus. But if this is the true explanation of Ramsay’s results, it is difficult to understand why, in the case of the experiment with a solution of a copper salt described below, the presence of neon was not detected, for, if due to leakage, the proportions of the rare gases present should presumably have been the same in all the experiments. Further research seems necessary conclusively to settle the question. [118] Sir WILLIAM RAMSAY: “The Chemical Action of the Radium Emanation. Pt. I., Action on Distilled Water,” _Journal of the Chemical Society_, vol. xci. (1907), pp. 931 _et seq._ ALEXANDER T. CAMERON and Sir WILLIAM RAMSAY, _ibid._ “Pt. II., On Solutions containing Copper, and Lead, and on Water,” _ibid._ pp. 1593 _et seq._ “Pt. III., On Water and Certain Gases,” _ibid._ vol. xciii. (1908), pp. 966 _et seq._ “Pt. IV., On Water,” _ibid._ pp. 992 _et seq._ [119] _Journal of the Chemical Society_, vol. xciii. (1908), p. 997. [120] E. RUTHERFORD, F.R.S., and T. ROYDS, M.Sc.: “The Action of Radium Emanation on Water,” _Philosophical Magazine_ [6], vol. xvi. (1908), pp. 812 _et seq._ Ramsay’s Experiments on Copper.