The Spark Spectrum of Cobalt, Co II

A further examination of the Co II spectrum, based on the previous work of Meggers, has been made. A magnetic analysis shows that Meggers' classification of the terms now called $d^{7}p{}_{}{}^5{}_{}{}^{}F_{}^0{}_{}{}^{}$, ${}_{}{}^5{}_{}{}^{}D_{}^0{}_{}{}^{}$ should be interchanged, except for the term ${}_{}{}^5{}_{}{}^{}F_5^{}{}_{}{}^0$. Since Meggers' results were obtained from intensity rules, the author's ${}_{}{}^5{}_{}{}^{}F{}_{}{}^5{}_{}{}^{}F_{}^0{}_{}{}^{}$ and ${}_{}{}^5{}_{}{}^{}F{}_{}{}^5{}_{}{}^{}D_{}^0{}_{}{}^{}$ multiplets show irregular intensities. The strongest lines in these multiplets are, respectively, ${}_{}{}^5{}_{}{}^{}F_n^{}{}_{}{}^{}{}_{}{}^5{}_{}{}^{}F_{}^0{}_{n-1\mathrm{}}{}^{}$ and ${}_{}{}^5{}_{}{}^{}F_n^{}{}_{}{}^{}{}_{}{}^5{}_{}{}^{}D_{}^0{}_n{}^{}$. The magnetic analysis also shows that Meggers' terms ${}_{}{}^3{}_{}{}^{}D$ should be $d^{7}s{}_{}{}^5{}_{}{}^{}P$ and that his ${}_{}{}^3{}_{}{}^{}P$, ${}_{}{}^3{}_{}{}^{}D_{}^1{}_{}{}^{}$, and ${}_{}{}^3{}_{}{}^{}F$ should be partly $d^{7}p{}_{}{}^5{}_{}{}^{}P_{}^0{}_{}{}^{}$ and ${}_{}{}^5{}_{}{}^{}D_{}^0{}_{}{}^{}$. In addition, the terms $d^{7}s{}_{}{}^3{}_{}{}^{}F$, $d^{7}p{}_{}{}^3{}_{}{}^{}D_{}^0{}_{}{}^{}$, ${}_{}{}^3{}_{}{}^{}F_{}^0{}_{}{}^{}$, ${}_{}{}^3{}_{}{}^{}G_{}^0{}_{}{}^{}$, ${}_{}{}^5{}_{}{}^{}S_{}^0{}_{}{}^{}$, ${}_{}{}^5{}_{}{}^{}P_0^{}{}_{}{}^{}$, ${}_{}{}^5{}_{}{}^{}D_{}^0{}_{}{}^{}$, and the lowest terms $d^8{}_{}{}^3{}_{}{}^{}F$ have been found. The location of the second member of the $d^{7}s{}_{}{}^5{}_{}{}^{}F{}_{}{}^3{}_{}{}^{}F$ series gives an I. P. of 16.9 volts from $d^{7}s$ to $d^7$ and 17.3 volts from $d^8$ to $d^7$, in practically exact agreement with the predictions of Dr. H. N. Russell.