Quaternary ammonium co-polymers for controlling the proliferation of bacteria

A method of controlling the proliferation of bacteria which comprises applying to said bacteria an effective amount sufficient to inhibit their growth, of a product formed by the condensation of a mixture of difunctional tertiary amines and a molar quantity of 1,4-dichloro-2-butene that is substantially equal to the molar sum of the mixture of difunctional tertiary amines, said mixture of difunctional tertiary amines being selected from the group consisting of (a) 1,4-bis-(dimethylamino)-2-butene and N,N,N',N'-tetramethylethylenediamine and (b) 1,4-bis-(dimethylamino)-2-butene and 1,4-bis-(methyl dodecylamino)-2-butene.