Long-range Particles from Radium-active Deposit

Abstract

IN a letter to NATURE under this heading (Sept. 22, 1923, p. 435), Messrs. L. F. Bates and J. S. Rogers announce that they have found a certain number of long-range-particles and also of H-particles to be discharged from radium C. For every ten millions of the ordinary-particles of 7 cm. range they claim to have found the following numbers of long-range-particles: 380 of 9.3 cm., 126 of 11.1 cm., and 65 of 13.2 cm., besides 160 particles of still greater range, assumed to be H-particles. In a more detailed report of their experiments (Proc. Roy. Soc. A, vol. 105, p. 97, 1924) the latter number is stated to include also H-particles expelled from the air and the mica traversed by the ordinary-particles. Similar particles of different ranges exceeding those of the ordinary particles are stated to come also from thorium C, from actinium C, and, according to a second letter to NATURE (Dec. 29, 1923, p. 938), also from polonium.