FEBRUARY,
1943
59
lithium and the resulting transmutations liberate energetic alpha-particles, attempts are being made by Kruger and others (21) to localize these elements in tissues to be irradiated. One cannot help being impressed by the rapidity with which discoveries in the field of nuclear physics have been put to practical use. Ten years ago, a cyclotron was a luxury which few universities could
afford. Its products are formed in such meager amounts tbat they cannot be weighed. Ten years ago such research was pure science indeed. Today the products of transmutations are used in the steel mill and in the hospital. Physicists, chemists, and physiologists have pooled their knowledge and resources and with such collaboration who can predict what will develop in the future?
LITERATURE
I (1) VAN ATTA, NORTHRUP, VAN ATTA, AND VAN OER GRAAFF,
Phys. Rev., 49, 761-76 (1936). (2) LAWRENCE AND LIVINGSTON, ibid., 45, 608-12 (1934); LAWRENCE AND COOKSEY, ibid., 50, 1131--40 (1936);
LIVINGSTON, Rev. Sci.lnstr., 7, 55--68 (1936). (3) FeRMI, Pro
