Ductility

Ductility is that property of solids in virtue of which they can be drawn out so as to increase their length at the expense of their cross dimensions. Thus silver is a very ductile metal, while platinum is not so ductile. But although platinum cannot be drawn out to any very great extent by the ordinary process of wire-drawing, it may be drawn out by Wollaston's process. Wollaston fitted a platinum wire into the interior of a hollow rod of silver, and then drew out the compound rod to an extent limited only by the ductility of silver. He then dissolved off the silver, and so obtained an excessively fine platinum wire, the diameter of which was, according to Leslie, $\backslash frac\{1\}\{50000\}$ inch. Leslie also says that, by drawing out a thickly-gilt silver rod, a film of gold only $\backslash frac\{1\}\{500000\}$ inch in diameter could be obtained. See MALLEABILITY, WIRE.