The adsorption of amyl alcohol on Ag(111) electrodes from 0.05 mol dm(-3) KClO4 aqueous solutions was studied by means of capacitance curves and potential steps. The results were compared with those obtained by Popov and coworkers using a capacitance bridge with differently prepared electrodes. Differences and inconsistencies are discussed in terms of experimental technique and electrode surface preparation. Amyl alcohol is less well adsorbed on Ag(111) than it is on Hg. Literature data for polycrystalline Au are also scrutinized for a comparative analysis. The capacitance under adsorption-desorption peaks is severely affected by frequency effects more at positive than at negative charges. Analysis of the peak parameters may lead to inconsistent conclusions. The superiority of the coulometric technique needs to be confirmed by further data since the physical picture is sometimes puzzling.