Abstract: A quaternary ammonium salt of the formula: ##SPC1## ##EQU1## wherein A is a lower alkylene, a lower alkenylene or a lower alkadienylene; R.sub.1 and R.sub.2 are each lower alkyl which may be linked together directly or by an oxygen atom to form a saturated heterocyclic group; R.sub.3 is a lower alkyl, a halo (lower) alkyl, a lower alkynyl, phenyl (lower) alkyl which may have one or more halogen atoms as substituents on the phenyl ring, a lower alkenyl, a hydroxy (lower) alkyl, a carboxy (lower) alkyl or a lower alkenyloxycarbonyl (lower) alkyl; R.sub.4, R.sub.5 and R.sub.6 are each lower alkyl having 1 to 3 carbon atoms; X is an acid residue; and wherein the cyclohexyl ring may have one double bond, with the proviso that when the cyclohexyl ring has one double bond in the 1,2 position, A may not be ##EQU2## when X.sup.- is iodide, R.sub.4, R.sub.5 and R.sub.6 are all methyl; R.sub.1, R.sub.2 and R.sub.3 are all methyl or all ethyl, or R.sub.1 is methyl, R.sub.2 is ethyl and R.sub.