The late Emperor Augustus was in the habit, at first, of using the figure of a Sphinx[2907] for his signet; having found two of them, among the jewels of his mother, that were perfectly alike. During the Civil Wars, his friends used to employ one of these signets, in his absence, for sealing such letters and edicts as the circumstances of the times required to be issued in his name; it being far from an unmeaning pleasantry on the part of those who received these missives, that the Sphinx always brought its enigmas[2908] with it. The frog, too, on the seal of Mæcenas, was held in great terror, by reason of the monetary imposts which it announced. At a later period, with the view of avoiding the sarcasms relative to the Sphinx, Augustus made use of a signet with a figure upon it of Alexander the Great. CHAP. 5.—THE FIRST DACTYLIOTHECÆ AT ROME. A collection of precious stones bears the foreign name of “dactyliotheca.”[2909] The first person who possessed one at Rome was Scaurus,[2910] the step-son of Sylla; and, for a long time, there was no other such collection there, until at length Pompeius Magnus consecrated in the Capitol, among other donations, one that had belonged to King Mithridates; and which, as M. Varro and other authors of that period assure us, was greatly superior to that of Scaurus. Following his example, the Dictator Cæsar consecrated six dactyliothecæ in the Temple of Venus Genetrix; and Marcellus, the son of Octavia,[2911] presented one to the Temple of the Palatine Apollo. CHAP. 6.—JEWELS DISPLAYED AT ROME IN THE TRIUMPH OF POMPEIUS MAGNUS. But it was this conquest by Pompeius Magnus that first introduced so general a taste for pearls and precious stones; just as the victories, gained by L. Scipio[2912] and Cneius Manlius,[2913] had first turned the public attention to chased silver, Attalic tissues, and banquetting-couches decorated with bronze; and the conquests of L. Mummius had brought Corinthian bronzes and pictures into notice.