Résumé : A series of ten aromatic aldehydes have been reduced at the dropping mercury electrode in dry D.M.F. Oscillopolarography has shown (table III) that the first wave is reversible at 20 Hz. The half‐wave potentials correlate reasonably well (table IV) with the energy of the lowest vacant M.O. Copyright © 1969 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim