1. Pt. Livingood,Phys. Rev.,34, 185, 1929.
2. Ir. W. Albertson,Phys. Rev.,42, 443, 1982.
3. Os. W. Albertson,Phys. Rev.,45, 304, 1934.
4. B denotes a line given by L. Bloch & E. Bloch,Journ. de Physique,2, 249, 1921.
5. M indicates blend with Hg III line classified by McLennan, McLay & Crawford,Trans. Roy. Soc. Canada,22, 248, 1928.