“…There was the plot of phenol (3) on the line. Further parallel shift of line shown as shadow area (d) covered the plots of m-, p-phthalic acids (6,7), m-, p-hydroxybenzoic acids (9,10), and m-, p-benzene diols (12,13). Retentions of these solutes having two substituted carboxyl groups and/or phenolic hydroxyl groups added further contributions of carboxyl groups and phenolic hydroxyl groups to the retentions of benzoic acid and phenol.…”