If we exclude certain fragmentary notices in Egyptian literature—notably the statements in the Ebers Papyrus—and the very uncertain sources in Hindu literature, the earliest authority for this branch of the subject is the Natural History of Pliny. In this connection, however, it is only just to call attention to a fact which has been often ignored—namely, that Pliny himself had very little faith in the teachings of the “magi,” as he calls them, in regard to the superstitious use of gems for the prevention or cure of diseases; indeed, he seems to have been almost as sceptical in his attitude as many modern writers, for certain quite recent authorities still credit amber and a few other mineral substances with therapeutic effects other than those which can be explained by the known action of their chemical constituents. Still, Pliny yielded so far to the taste of his time as to preserve for us many of the statements of earlier writers on the subject, naming them in most cases and so enabling us to form some idea of the character of this pseudo-science in the Roman world in the first century of our era. With the gradual decay of ancient learning, the less valuable elements of popular belief came more and more into the foreground, and the old superstitions were freely copied by successive authors, each of whom felt called upon to add something new on his own account. This explains much of the confusion that reigns in regard to the attribution of special virtues to the different stones, for the wider the reading of the author the greater became the number of virtues attributed to each separate stone, until, at last, we might almost say that each and every precious stone could be used for the cure of all diseases. Nevertheless, it is comparatively easy to see that either the color or constitution of the stone originally indicated its use for this or that disease. [Illustration: INSCRIPTION ON A SMALL PIECE OF LIMESTONE, IN CURSIVE EGYPTIAN WRITING. It dates from about 1600 B.C., the period of the Ebers Papyrus, and gives directions for preparing certain remedies from precious stones. While the interpretation of this text offers considerable difficulty, one version finds in it the statement that lapis-lazuli—the “sapphire” of the ancients—was used for the wealthy, and malachite for those of limited means. Professor Oefele conjectures that the disease to be treated was hysteria. Munch Collection, Metropolitan Museum of Art, New York.]