Abstract. Fluorides and other halides are hydrolyzed completely by passing a rapid stream of superheated steam over the sample near 1000 degrees C in a specially designed platinum reaction tube. The steam and hydrogen halide are condensed by cooling, and the resulting distillate titrated with standard sodium hydroxide solution. The fluorides and chlorides of the light metals, hitherto thought of as very difficult to hydrolyze, are mixed with U3O8, or other metallic oxides, which reacts with the products of hydrolysis, thus shifting the equilibrium so that the reaction is complete in a comparatively short time. A description of the apparatus, including photographs, the recommended method of procedure, hydrolysis rate graphs, and suggestions for further applications of the method are given.

Technical report on the studies that have been made on the composition and thermal decomposition of uranyl peroxide. The conditions of precipitation and drying have been found to have no appreciable effect on the composition of the compound, but do affect the physical appearance of the precipitate and the rate of thermal decomposition. The UO4 + 2H2O appears to be thermodynamically unstable with respect to UO3 at 25 degrees C and atmospheric pressure, although the rate of conversion is extremely slow. The UO4 + 2H2O is completely converted to UO3 on standing at 150 degrees C and atmospheric pressure for two weeks. Partially decomposed uranyl peroxide samples contain extra oxygen which is released on immersing the sample in water.