The wire-drawing of metals depends on the property of solid bodies, which renders them capable of being extended without any separation of their parts, while their thickness is diminished. This property is called "ductility."

The following is nearly the order of ductility of the metals which possess the property in the highest degree, that of the first mentioned being the greatest: gold, silver, platinum, iron, copper, zinc, tin, lead, nickel, palladium, cadmium.

Dr. Wollaston succeeded in obtaining a wire of platinum only 1/30000th of an inch in diameter. The ductility of glass at high temperatures seems to be unlimited, while its flexibility increases in proportion to the fineness to which its threads are drawn.