Note 2419 — BOOK XXXVI. THE NATURAL HISTORY OF STONES.
John Bostock translation
Both Liber and Libera were originally Italian Divinities, who presided over the vine and the fields. Pliny, however, always identifies the former with Bacchus, and other writers the latter with Persephone, or Proserpina, the daughter of Demeter or Ceres. Ovid, Fasti, B. iii. l. 512, calls Ariadne, “Libera.”