Source : Webster's Revised Unabridged Dictionary (1913)

Sodium sulphate \So"di*um sul"phate\
   A salt well known as a catharic under the name of {Glauber's
   salt}, which term is properly applied to the hydrate,
   {Na2SO4.10H2O}.

Source : WordNet®

sodium sulphate
     n : a solid white bitter salt used in manufacturing glass and
         paper and dyes and pharmaceuticals [syn: {sodium sulfate}]