Hexahydrate prepd by adding sodium selenite to a soln of magnesium chloride: Nilson, cited in Mellor's 10, 826 (1930); by treating a soln of magnesium chloride or sulfate with selenious acid and adding sodium carbonate to start precipitation: Boutzoureano, Recherches sur les Sélénites (Paris, 1889).
This monograph has been retired and is no longer subject to revision or update.