Beads made by this process belong strictly to the class of _blown_ glass. The other system which we will now describe takes us back to the old primitive methods of glass-working. In this case we start from a _solid_ rod of glass, which is manipulated in the hand of the workman somewhat like a stick of sealing-wax. Seated at a table, he melts the extremity of the _canna_ in the flame, directed away from him by means of a blow-pipe, and twists the thread of viscid glass around a small rod of iron.[139] By this or similar methods, not only beads but various small objects of _verroterie_ are formed. The surface of these may be subsequently decorated by means of _appliqué_ studs and stringings of various coloured glass, or again, the half-fused substance may be pressed into little moulds. The spun-glass also, so much admired a few years since, is made from rods of glass melted in the flame of the table blow-pipe. This is the process of the _suppialume_, in which the Venetian workmen acquired such skill in later days. It cannot be traced further back than the end of the fifteenth century, and its invention is associated with a certain Andrea Vidaore. The guild of the _suppialumi_ was only finally constituted in 1648. If this process was really only introduced at so comparatively late a date, we have here a curious instance of a reversion to an old technique, for it is impossible to overlook the points of resemblance between it and the manner in which the ancient Egyptians built up their beads.[140] It must be noted that the practical difference between the beads made by the _suppialumi_ and those formed from hollow tubes, is not one of size. Large or small beads may be formed by either process. It is, rather, that in the first case the ornament is superficial—it is something added to the surface of the bead. On the other hand, in beads made from hollow tubes, the design, though limited in variety, is carried through the whole bead. This is a distinction much appreciated by native connoisseurs in Central Africa and elsewhere.