MISCELLANEOUS. S25 



A Method q/^ Silvering Ivory, 



Take a slip of ivory, immerse it in a weak solu- 

 tion of nitrate of silver, and let it remain in it till 

 the ivory has acquired a bright yellow colour ; then 

 take it out of the solution, and immerse it in a 

 tumbler of pure water, and expose it in the water 

 to the rays of a very bright sun. After the ivory 

 has been exposed to the sun's rays for about two 

 or three hours, it becomes black ; but on rubbing 

 it a little, the black surface will become changed 

 into one of silver. Although this coating of silver 

 is extremely thin, yet if the ivory be well impreg- 

 nated with the nitrate of silver, the solution will 

 penetrate to a considerable depth; and as fast as 

 the silver wears off from the surface of the ivory, 

 the nitrate below being exposed to the light, is con- 

 verted into silver, and the ivory retains its metallic 

 appearance. 



To cover Ribbons with Gold by a Chemical Process. 



Let ether stand over phosphorus for some weeks, 

 and some of the phosphorus will be dissolved. 

 Dissolve also some gold in aqua regia (nitro-mu- 

 riatic acid). Dip the ribbon, first, into the nitro- 

 muriatic solution, and then into the phosphorated 

 ether, and it will be covered with a firm coating of 

 gold. 



The same efi'ect may be produced by exposing 

 the ribbon, after having dipped it into the solution 

 of gold, to a current of phosphorated hydrogen gas 

 for some days. 



To prepare Aurum Musivum. 



Aurum musivum is used by japanners, and for 

 many varnished works, as snuff-boxes, coaches, &c. 



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