"8 Of the Gold 



this method of working pyrites for gold fhould feem 

 to be performed per fe, without any foreign addi- 

 tions, yet that there only happens a bare feparation, 

 as no methods of coction, maceration, digeftion, 

 and maturation, have preceded, may prove a mere 

 precarious alTertion, without confidering in the lead 

 the nature of lead in its volatility and activity, the 

 efficacy of fulphur, and the mercurial feminal vir- 

 tue of arfenic •, especially when thefe powerful agents 

 happen to be applied to, and to find proper tender 

 matrices. All thefe are here effectually applied, 

 whether the operation be carried on in the way of 

 roafting, or of fcorification with lead, the metallic 

 earths exhibiting themfelves as fo many tenderly 

 prepared matrices : and fuppofing the parts of the 

 pyrites to do nothing towards the transformation 

 and exaltation, yet the fire acts here no inconfide- 

 rable part, not only in the way of a feparation, but 

 alfo of an influx ; whether by enriching the phlogi- 

 fton, and metallifing the matter, or by a higher 

 virtue ftill, may be made a queftion. 



Whilft I was engaged in thefe reflections, there 

 came to my hands an extraordinary experiment of 

 M. Homberg, from which he maintains, and with 

 a good deal of probability, that in filver are con- 

 tained particles of a gold-nature, which, in the 

 courfe of the procefs, at firft become perfect gold. 



* Take between one and two marks of filver, which 



* being aflayed in the ufual manner, with aqua- 



* forth ', in order to afcertain its containing no gold, 



* melt it an hundred times over, and having con- 



* tinued it each time in flux for an hour at lead, 

 " depart it ; you will procure a very fenfible quan- 

 c tity of gold, which before was not to be found 



* in the filver *.* 'Tis pity our author did not fct 



down 

 * Mem. de l'Acad. &c. Pan. 1709. p. 141. 



