"The Heart of Arethusa" is a novel written by Frances Barton Fox. Unfortunately, there is limited information available about this specific book or its author. It's possible that it was published in a period where records are less accessible or it may be a lesser-known work.However, based on the title, "The Heart of Arethusa" could potentially be a romantic or adventurous tale, possibly with elements of mythology or fantasy, considering "Arethusa" is the name of a nymph in Greek mythology associated with freshwater sources.