Chap. 35.] [ 227 ] 



CHAP. XXXV. 



GOLD. 



General Properties of Gold. Gold calcined by Elefiricity.Extrtmt 

 Duflillity of this Metal Natural Hiftory of Gvld.-~ProceJ/es for 

 feparating Gold from other SutJJances. Quartaticn. 'The Touch- 

 Jlone. Aqua Regia. Reafons <vchy the different Acids aft on metallic 

 Bodies. Fulminating Gold, Purple Powder of Coffins. Golden 

 Calf, how deftroyed by Mcfes. Union of Gold with other M(T/A. 

 Standard Gold Coin of different Countries. 



GO L D is the heavieft of all the metals except 

 platina, being between nineteen and twenty times 

 the weight of water. When perfectly pure it is al- 

 moft as foft as lead, and is neither elaftic nor fonorous* 

 For its fufion it requires rather more heat than filver, 

 and when in fufion has a blueifh green colour, and its 

 fuiface is always perfectly bright. The moft intenfe 

 heat cannot calcine it, and only contributes to render 

 it more pure if it had any foulnefs. The powerful 

 burning mirrors are faid to have volatilized it, and it 

 has been driven up in fumes, in the metallic date, by 

 flame urged upon it by a ftream of vital air. The 

 electric fluid, however, when rrmde to pa-fs in confi- 

 derable quantities through gold leaf, inciofed between 

 two plates of glafs, converts it into a calx, which tinges 

 the glafs of a purple colour. 



The tenacity of fgold is fo great, that a wire one-tenth 

 of an inch in diameter is capable of fupporting five 

 hundred pounds. Its malleability and ductility exceed 

 thofe of filver, and are fo remarkable, that their limits 

 could never be afcertained with any confiderable ex- 

 actnefs. On gold lace the thicknefs of the gold has 



Q2 been 



