Abstract: "Experiments are described wherein uranium metal was heated in ten different refractory materials under conditions approximating those of the uranium J. The refractory crucibles containing the uranium were placed in graphite crucibles and heated in vacuum for four hours at 1800-1850 C by means of an induction furnace. MgO, W, and TiH were found to be unacceptable containers for uranium at these temperatures. BeO, ThO2 and Un showed some reaction with the uranium, whereas UO2, ZrH, CeS, and ThS were only very slightly affected by the uranium during the runs."