Note 290 — Chapter V · THE SECOND CHALCITIC AGE OF ALLOYS[242]—BRONZE, BRASS, ETC.: THE AXE AND THE SWORD.

Pliny, xxxiii. 27. The solder (χρυσός and κόλλα, glue, or κόλλησις) is attributed by Herod. (i. 25) to Glaucus of Chios, a contemporary of Alyattes. The word kóllesis is variously rendered ‘soldering,’ ‘brazing,’ ‘welding,’ and ‘inlaying.’ Kóllesis was used to agglutinate metals, and treated with a peculiar alkali (Pliny, xxxiii. 24). The ‘gold glue’ (chrysocolla) is usually understood to be a hydrosilicate of copper; not to be confounded with the χρυσόκολλα or borax. The Mycenian goldsmiths soldered with the help of borax (borate of soda): Professor Landerer, of Athens, found this salt on an old medal from Ægina. It was called in the Middle Ages, Borax Venetus, because imported by the Venetians from Persia; and it is the Tinkal of modern India. According to Pliny, lead cannot be soldered without tin, or tin without lead, and oil invariably must be used. Later usage substituted for the latter colophonium and other resins: we now solder by means of electricity. The same writer makes Nero use chrysocolla-powder (a siliceous carbonate of copper, a kind of blue-stone which would turn green by exposure to damp) for strewing the circus, to give the course the colour of his favourite faction, the Prasine (green).