We obtain the class NA of noncommutative cylindric algebras from the class CA of cylindric algebras by weakening the axiom C4 of commutativity of cylindrifications . Some motivation for studying noncommutative cylindric algebras: Noncommutative cylindric algebras have the same “substitutional structure” as cylindric algebras , where substitutional structure refers to the equational behaviour of the substitution operations, the s i j ’s. For certain technical reasons, NA’s turn out to be useful in the study of the substitutional structure of CA’s. (...) Cf. Thm. 3 below. (shrink)