Galba (3–69 B.C.), Nero’s immediate successor, is said to have used successively three signets, the first depicting a dog bending its head beneath the prow of a ship; this was followed by a ring showing a Victory with a trophy, and lastly came one bearing the effigies of his ancestors. As his reign of less than a year seems too short for us to suppose that all these changes were made in that time, perhaps only the last-mentioned ring was the one he used as emperor. Commodus (161–192 A.D.), the unworthy son of the philosopher-emperor, Marcus Aurelius, had the figure of an Amazon engraved for his signet, this choice having been made, so it is said, because of the pleasure he took in seeing his mistress Martia dressed in this way. Augustus Cæsar reposed such unlimited confidence in his son-in-law, Agrippa, and in his friend and finance minister, Mæcenas, that he was in the habit of confiding his letters to them for correction, and gave them permission to send off the corrected letters, bearing the stamp of his signet which he had deposited in their charge, without submitting them again to him. Similar trust was reposed by Vespasian in Mutianus.[220] The seal was stamped on a linen band passed around the closed tablets on the inside surfaces of which the letter had been written. The impression, made when the ends of the band were joined, was either upon wax, soft viscous earth, or even on a mixture of chalk; this was commonly moistened with saliva before the signet was used, so that the engraved stone might not adhere to the imprint and could be easily taken off. The bearer of such a letter fully realized his responsibility for its delivery with unbroken seal, and generally took pains to have this duly recognized by the person to whom it was addressed.[221] The personal seal was also impressed, both in Roman times and later, upon all documents private or public. In the case of private documents the strictly guarded individuality of the seal really afforded a very considerable guarantee of the genuineness of a document. A survival of this is the common little red seal attached now-a-days to legal documents, necessary to their validity it is true, but giving no possible confirmation of the signature. This latter was in fact represented by the design of the old signets. The “Dream Book” of Artemidorus relates as an especially direful vision, that of one who dreamed his signet ring had dropped from his finger, and that the engraved stone set therein had broken into many fragments, the result of this being that he could transact no business for forty-five days,[222] presumably until he could have a new signet engraved. For the impression of the individual signet was indispensable to give validity to any order or agreement. [Illustration: Two brass rings. Roman. 1, set with an inscribed agate,; 2, key-ring, set with an engraved onyx Gorlæus, Dactyliotheca, Delphis Bat., 1601]