180 SILVER. 
form, been extended nearly to the length of 400 feet. 
It is this wire gilded that has the name of gold wire ; 
and what is denominated gold lace (227) is but flatted 
silver thread gilt, twisted round silk, and woven. 
The plating of copper with silver is a very useful 
operation, and is thus performed. Plates of silver are 
bound with iron wire, upon small ingots of copper. 
The quantity generally allowed is one ounce of silver 
to twelve ounces of copper. The surface of the plate 
of silver is made not quite so large as that of the cop- 
per ; and upon the edges of the copper, which are not 
covered by the silver, a little borax (204<) is put. By 
exposing the whole to a strong heat, the borax melts ; 
and, in melting, contributes to fuse that part of the silver 
to which it is contiguous, and to attach it, in that state, 
to the copper. The ingot, with its silver plate, is then 
rolled between steel rollers moved by machinery, till it 
is of proper thickness. It is afterwards cut into such 
sizes and to such shapes as may be required for use. 
An ounce of silver is thus often rolled out into a surface 
of three square feet, having its thickness, upon the cop- 
per, not more than the three-thousandth part of an 
inch. Hence we ought not to be surprised at the silver 
being soon worn from the sharp edges of plated goods. 
To prevent this, it is customary, with the best articles, 
to have all the edges, and the parts liable to be worn, 
formed, to a considerable thickness, of silver. 
What is called French plate is made by heating cop- 
per, or more frequently, brass, to a certain degree, then 
applying leaf-silver to the surface, and strongly rubbing 
it with a burnisher. The durability of this plating de- 
pends of course on the number of leaves which are ap- 
plied on a given surface. For ornaments that are not 
much used ten leaves may be sufficient ; but a hundred 
will not last long, if the metal be exposed to frequent 
handling or washing. 
Besides the above, there are various modes of silver- 
ing metal articles, or, as it is called, washing them with 
