The adsorption-desorption phenomena of alcohols were studied by measuring differential capacity-time curves in a flowing solution. The alcohols investigated were methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol. The differential capacity-time curves for these alcohols show different shapes with and without peaks. These curves are explained qualitatively. The curves were used to study the adsorption reversibility of the alcohols at a mercury electrode. The adsorption of methanol is irreversible and that of ethanol is almost irreversible. Some of the adsorbed molecules of 1-propanol are desorbed. The adsorption of 1-butanol is almost reversible, and the adsorption of 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol is reversible.