The Production of Neon from Emanation.
§ 97. As we have already indicated above ([§ 93]), the radium emanation contains a vast store of potential energy, and it was with the idea of utilising this energy for bringing about chemical changes that Sir William Ramsay[118] undertook a research on the chemical action of this substance—a research with the most surprising and the most interesting results, for the energy contained within the radium emanation appeared to behave like a veritable Philosopher’s Stone. The first experiments were carried out on distilled water. It had already been observed that the emanation decomposes water into its gaseous elements, oxygen and hydrogen, and that the latter is always produced in excess. These results were confirmed and the presence of hydrogen peroxide was detected, explaining the formation of an excess of hydrogen; it was also shown that the emanation brings about the reverse change to some extent, causing oxygen and hydrogen to unite with the production of water, until a position of equilibrium is attained. On examining spectroscopically the gas obtained by the action of the emanation on water, after the removal of the ordinary gases, a most surprising result was observed—the gas showed a brilliant spectrum of neon, accompanied with some faint helium lines. A more careful experiment was carried out later by Sir William Ramsay and Mr. Cameron, in which a silica bulb was employed instead of glass. The spectrum of the residual gas after removing ordinary gases was successfully photographed, and a large number of the neon lines identified; helium was also present. The presence of neon could not be explained, in Ramsay’s opinion, by leakage of air into the apparatus, as the percentage of neon in the air is not sufficiently high, whereas this suggestion might be put forward in the case of argon. Moreover, the neon could not have come from the aluminium of the electrodes (in which it might be thought to have been occluded), as the sparking tube had been used and tested before the experiment was carried out. The authors conclude: “We must regard the transformation of 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.