Even until the latest times the ring retained its original purpose as a means of distinction or of recognition, and was used by its wearer to impress his seal on documents and private property. It continued also to be associated with the idea of power and privilege especially bestowed upon the individual. Thus the Roman paterfamilias wore on his finger a ring with a small key attached. Every Roman appears to have chosen at pleasure the subject or device for his signet--a portrait of a friend or an ancestor, or some subject from poetry or mythology. Each of these devices became associated with a particular person, and served, like the coat-of-arms of later centuries, as a mark of identification. The commonest variety of ring is formed of a plain band of gold which widens and thickens towards the bezel, and is set with a small stone. The latter is generally engraved, but is often quite plain. The similarity of the convex sardonyx to an eye often struck the ancients, and may account for this stone being frequently found unengraved in rings, and set in a collet, itself shaped into the form of a human eye. Such rings were no doubt worn as amulets. Rings containing stones set in this manner have sometimes a flattened hoop and open-work shoulders. Other distinctly ornamental rings, known by the Romans as _polypsephi_, are formed of two or more rings united together. A large number of Roman rings are of bronze, and the key rings referred to are, with a very few exceptions, of this material. Iron and bronze rings were not infrequently gilded. Such rings, according to Pliny, were called Samothracian. Rings in the form of snakes were very popular, as were those shaped like a Herculean knot. Like other articles of jewellery, rings are sometimes set with gold coins of the late Empire. A few ornamental rings have high pyramidal bezels which were sometimes hollow, and were made to contain poison. Hannibal killed himself with a dose of poison which he carried about with him in his ring; so did the officer in charge of the temple of Jupiter Capitolinus. "Being arrested," says Pliny, "he broke the stone of his ring between his teeth and expired on the spot." CHAPTER V BYZANTINE JEWELLERY The peculiar interest of Byzantine jewellery lies, not only in its own composite nature, but in the great influence it exercised on European ornaments during the greater part of the Middle Ages. Byzantine jewellery is the result of a compromise between Oriental and Western influences. It retains the craftsmanship of ancient Rome and the dignity of classical traditions modified by Christian ideas, and to these it unites the skill in patient and exuberant decoration in which the Oriental workman excels.