The dipole moments of 2-amino-1 ∶ 4-dimethoxy benzene and of 2-amino-1 ∶ 4-diethoxy benzene have been studied in benzene and in carbon tetrachloride solution. The values of the moments are discussed in relation to the moments of the unsubstituted parent carbon compounds. The interaction between three groups of similar characteristics is considered in relation to their steric effects.