On The Spectra of Gallium, Germanium and Indium

The vacuum-spark spectra of gallium germanium and indium have been photographed in the ultra-violet by means of a two-meter vacuum spectrograph using a grating of 30,000 lines per inch. The known series lines of Ga III and Ge IV have been remeasured and certain new ones discovered. Term values have been recalculated. The series spectra of Ga II, Ge III, and In II have been worked out for the multiplets $4{}_{}{}^3{}_{}{}^{}P-5\mathrm{}{}_{}{}^3{}_{}{}^{}S$, $4{}_{}{}^3{}_{}{}^{}P-4\mathrm{}{}_{}{}^3{}_{}{}^{}D$, $4{}_{}{}^3{}_{}{}^{}P-4\mathrm{}{}_{}{}^3{}_{}{}^{}P_{}^{\prime }{}_{}{}^{}$ and $4{}_{}{}^1{}_{}{}^{}S-4\mathrm{}{}_{}{}^1{}_{}{}^{}P$.