>Results of solvent extraction studies on Au, Ga, Nb, and Ta are given. Data on the dependence of B/sub A/, epsilon /sub A/ and S/sub A/ on A and on nucleon shells in beta decay are summarized. Rates of hydrolysis of benzyl and benzhydryl halides and methyl iodide in H/sub 2/O and D/sub 2/O are tabulated. Values for the solvolysis of triphenplmethyl fluoride, the decarboxylation rates of beta -keto acids, and the decomposition of single chlorosulfites are included. Experiments were conducted to examine the velocity spectrum of cosmic ray mu mesons at sea level, the incidence of air showers and their direction of arrival at sites in Bolivia and India, short period fluctuations in cosmic-ray intensity, the mu -meson component of large air showers, polarization of cosmic-ray mu mesons, and other related measurements. Photographic emulsion research continued on the dynamics of K/sup +/ scattering and on a search for the Pais-Piccioni effects. The linear accelerator work centered about a study of gamma -ray induced neutron spectra of Bi, Pb, Au, and Ta. The Rockefeller Van de Graaff Generator work was concerned with the measurement of g-factors of low-lying excited states of Sm, Nd, and Gd. Nuclear energy level studies using the ONR Van de Graaff Generator were concentrated largely on the nuclei between mass numbers 40 and 70. Efforts were directed award a determination of level order and, where possible, of spins and parities of states. A number of angular distribution studies for deuterium stripping reactions were carried out. Research with the M.I.T. cyclotron involved a continuation of the angular distribution studies of elastically scattered 7.5-Mev protons, the measurement or polarization of such elastically scattered protons; 30-Mev alpha particle scattering, alpha ment of apparatus for time-of-flight neutron energy measurements. (For preceding period see AECU-3377.) (M.H.R.)