In addition to the more formal types of brooches, many fancy devices, probably of Celtic origin, appear to have been in vogue among the Roman colonists of Great Britain. These are in the shape of birds, fish, and all kinds of animals, brilliant with various coloured enamels, which are often so disposed as to indicate the spots or markings of the animals. A remarkable series of brooches of this kind is in the possession of Sir John Evans. Bracelets and armlets, usually of bronze, have survived in large numbers. They consist generally of a simple narrow ring, such as could be slipped over the wrist. Some are pennanular with tapering ends, others are closed with a hook and eye, while a few have their ends so twisted together that they can slide over one another and so be taken on and off. Armlets of glass, chiefly of a deep transparent blue, have also been found. Most of the varieties of finger rings already recorded appear to have been worn in Britain. The extent of the Roman civilisation can be measured by the number of engraved stones enclosed in their settings or found apart, the majority of which must have been executed by lapidaries on the spot. Many articles, such as rings, armlets, beads, buttons, and amulets, were formed of jet or Kimmeridge shale, turned on a lathe. In the Island of Purbeck round flat pieces of jet have been found pierced with holes, which are clearly refuse pieces of the turner--the nuclei of rings and other articles. This material appears to be the same as that termed by Pliny _gigates_. According to him, it was supposed to possess the virtue of driving away serpents; and personal ornaments made of it were particularly prized. There seems little doubt that the use of ornaments of Kimmeridge coal or shale by the Romano-Britons was nothing more than a survival of the Neolithic or Stone Age. "Great Britain," writes M. Fontenay in 1887, with reference to the ancient practice of wearing ornaments of jet, "remains faithful to its early customs; for at the present day English ladies delight in adorning themselves with jet jewellery." Fashion changes rapidly, but it will be long, one hopes, before it again decrees the general use of ornaments of this unattractive material. CHAPTER VII BARBARIC JEWELLERY OF EUROPE (THE GREAT MIGRATIONS) During the period of the great migrations, when hordes of barbarians swept like waves across Europe over the tracks of Roman civilisation, all traces of classical art rapidly vanished, save in Constantinople, which remained, as it were, a corner of the antique world. The forms of classical jewellery in natural course either totally disappeared or underwent a complete transformation, and there appeared instead a new process for the decoration of personal ornament, which in earlier times was practically unknown, save to the goldsmiths of ancient Egypt.