The following half-lives have been measured: ${\mathrm{Tm}}^{167}$, 9.25±0.1 days; ${\mathrm{Tm}}^{168}$, 93±0.5 days; ${\mathrm{Tm}}^{170}$, 125±2 days; ${\mathrm{Lu}}^{171}$, 8.2±0.1 days; ${\mathrm{Lu}}^{172}$, 6.7±0.1 days; ${\mathrm{Lu}}^{173}$, 499±5 days; ${\mathrm{Lu}}^{174}$ and ${\mathrm{Lu}}^{174m}$, 140±10 days; and 1300±150 days; ${\mathrm{Au}}^{195}$, 185±1 days; ${\mathrm{Au}}^{196}$, 6.17±0.05 days; ${\mathrm{Au}}^{196m}$, 9.7±0.1 h.

• Received 27 February 1962

DOI:https://doi.org/10.1103/PhysRev.127.217