In a recent article [Galesic and Jordanovska (1992). Acta Cryst. C48,
256-258], the structures of [Al(H2O)(6)](3+).C2H8N+.2SO(4)(2)- and the
corresponding chromium analogue were refined in the P2(1)n space grou
p. Despite the formal difference between the formula unit of these com
pounds, RM(III)(SO4)(2).6H(2)O, and the general formula of the Tutton
salts, M(2)(1)M(II)(SO4)(2).6H(2)O, both studied compounds may be cons
idered as variations in the Tutton salt structure.