On the spectrum of barium hydride

It is interesting to compare the spectrum of barium hydride with the hydride spectra of the other elements in the second column of the periodic system. As these elements have in the different atomic states a great similarity in their electronic configurations, it may be expected that the hydrides belonging to them show similar spectra, supposing that the molecules are formed in the same way, e.g. by the element in some atomic state and a normal H-atom as is actually the case. Indeed the hydride spectra have many features in common, but differ in some respects from element to element. For the discussion it may be useful to give a short description of the hydride spectra concerned, which have been analysed by several investigators. The spectra have been mostly obtained in an arc, containing the metal and burning in a hydrogen atmosphere. The experimental procedure is about the same as has been used for the investigation of the BaH spectrum