Mercury silvering Mercury silvering Mercury silvering or fire gilding is a silvering technique for applying a thin layer of precious metal such as silver or gold (mercury gilding) to a base metal object. The process was invented during the Middle Ages and is documented in Vannoccio Biringuccio's 1540 book "De la pirotechnia". An amalgam of mercury and the precious metal is prepared and applied to the object which is then heated, sometimes in oil, vaporizing most of the mercury. The technique is dangerous since mercury is highly toxic, especially in its vapor phase. Mercury silvering can be detected through a variety of
Wurtz reaction reaction occurs through a free radical mechanism. The reaction consists of a halogen-metal exchange involving the radical species R• (in a similar fashion to the formation of a Grignard reagent) with carbon–carbon bond formation occurring in a nucleophilic substitution reaction. One electron from the metal is transferred to the halogen to produce a metal halide and an alkyl radical. The alkyl radical then accepts an electron from another metal atom to form an alkyl anion. This intermediate has been isolated in several cases. The nucleophilic carbon of the alkyl anion then displaces the halide in an S2 reaction, forming a