Note 1 — PREFACE TO THE SECOND EDITION
Reading edition
See his “The Presence of Helium in the Gas from the Interior of an X-Ray Bulb,” Journal of the Chemical Society, vol. ciii. (1913), pp. 264 et seq.
[2] See their “The Presence of Neon in Hydrogen after the Passage of the Electric Discharge through the latter at Low Pressures,” ibid., pp. 419 et seq.; and “The Production of Neon and Helium by the Electric Discharge,” Proceedings of the Royal Society, A, vol. xci. (1915), pp. 30 et seq.
[3] See especially the report of negative experiments by Mr. A. C. G. Egerton, published in Proceedings of the Royal Society, A, vol. xci. (1915), pp. 180 et seq.
[4] See the Philosophical Magazine for June, 1919, 6th Series, vol. xxxvii. pp. 537-587.
[5] Or perhaps an isotope of helium (see below).