Abstract
It is well known that the inversion of the helium triplets and their deviation from interval rule are due to the spin-other-orbit and to the magnetic spin-spin interactions (respectively), which may be neglected in comparison with the spin-orbit interaction in treating the spectra of heavy elements. The preliminary calculation of Heisenberg is compared with the correct calculation of Breit for the lowest triplet. The extension to higher triplets, by Araki, is simplified and generalized, and the comparison with experiment is discussed.