1837 J. D. Dana 170 Solfatarite, alumen volcanicum. Soda Alum.
1876 J. Harley (ed. 6) 192 Soda alum and ammonia alum are formed by replacing the equivalent of potash with one of soda or ammonia.
1968 I. Kostov 494 As ‘alums’ are denoted the following double sulphates:..Soda alum NaAl(SO4)2.12H2O.