The Radiations ofTh231(UY)

$\beta$-ray spectrum studies on a double-lens spectrometer of the electron spectrum of UY revealed a complex spectrum with three beta-components of 302 kev (44 percent), 216 kev (11 percent), and 94 kev (45 percent), and numerous conversion lines assignable to gammas of 22, 59, 63, 85, 122, 167, and 208 kev, each of these except the 122 kev also observed directly as gammas in a scintillation spectrometer. There is also evidence for a 107- and for a 230-kev gamma-ray. The samples were separated carrier-free from isotopically pure ${\mathrm{U}}^{235}$ (99.86 percent) by solvent extraction. A decay scheme is presented which gives a total disintegration energy of 324 kev.