Ductility

Ductility is a property of matter well illustrated by silver, copper, and other metals, which enables it to be drawn out into widely different forms. Copper-wire may be forced through a hole in a metal plate so as to be diminished in diameter while undergoing an extension of its length. The process may be repeated several times, providing that the metal is occasionally annealed so as to avoid the brittle condition. The power of changing shape without breaking when the material is subjected to percussion is called malleability, a property closely allied to ductility and illustrated by the same class of metals. By an ingenious process of wire-drawing a silver cylinder with a platinum core, Wollaston succeeded in obtaining platinum wire of exceeding tenuity; one mile of it only weighed \\ grains.