The kinetic form of the suppression of the perchlorate catalysis of the methanolysis of triphenylmethyl chloride in benzene solvent by tetra-n-butylammonium chloride has been investigated. This is consistent with a catalysis brought about by a simple perchlorate ion, suppressed by a competition between such ions and alkylammonium chloride ion-pairs for the alkyl halide ion-pair.The results are discussed in relation to the qualitatively similar special salt effects observed in acetolysis reactions by Winstein and co-workers, with particular reference to the necessity of the concept of intimate and solvent-separated ion-pairs in the interpretation of these effects.