With a new type of especially stable electrolytic capacitor, the dielectric properties of anodic layers are measured. The investigation shows that variations of the dielectric properties may be divided into two classes: lagging and nonlagging variations. Lagging variations, which include variations of the capacity and power factor with the operaing voltages, are especially characteristic of anodic layers. They arise from the fact that the structure (organization) of layers adjusts itself with changes of the operating conditions to a new dynamic equilibrium, within a short transition period. On the other hand, in regard to variations of the capacity and power factor with frequency, which are nonlagging variations, anodic layers are similar to other composite dielectrics. An oscillographic study of harmonics is made which verifies the lagging nature of the changes of capacity with the operating voltages (a.c. and d.c.) and demonstrates for the first time the existence of a nonlagging variation of the a.c. conductivity with voltage.