Experiments upon the reported transmutation of mercury into gold

The possibility of effecting a transmutation of the atom by electronic bombardment, as distinct from the alpha-ray methods so successfully used by Rutherford and others, has attracted attention from time to time in resent years. The first to report success in such an experiment was Ramsay, who announced in 1912 the artificial production of helium and neon in X-ray bulbs. The controversy aroused by his announcement has not yet subsided, tor Riding and Baly have supported quite recently, in this Journal, the genuineness of such a transformation. Miethe, in 1924, reported the transmutation of mercury into gold, and since the original announcement he has described various experimental arrangements which he claims have proved successful. Two principal methods have been employed by this investigator. First, a Jaenicke mercury vapour lamp, operating at atmospheric pressure with a current of 12·5 amperes, a terminal voltage of 170, and a potential gradient of 11 or 12 volts per cm., was run for 20 to 200 hours, and amounts of gold up to 0·1 mg. reported, though no direct proportionality existed between the quantity of gold and the number of hours run. Miethe also reported the formation of silver in these experiments, often in larger amounts than the gold, and stated that the field of noble metals was increased by irregular burning of the arc, with frequent extinction and relighting. No gold was obtained from vacuum arcs. The second method was a development of the first, in which the effect of irregular burning was artificially enhanced by constant interruption of the arc. The final simplified form of this experiment consisted in the employment of an ordinary rotating mercury interrupter, and with this apparatus Miethe states that he obtained for the first time consistently reproducible results, a direct proportionality existing between the number of ampere hours run and the field of gold (about 4 x 10-7 gm. per ampere hour.) He also describes a series of experiments in which one and the same quantity of mercury (ca. 1·5 kg.) was submitted to a number of successive runs, about a score in all, when no diminution of the yield was observed. He states that self-inductance was here found to be absolutely without effect, though from certain earlier experiments he had believed that the inclusion of an inductance in the circuit increased the yield. No mention is made of the production of silver in these experiments.