MINERALOGY. %6 9 



SECT. CLXVII. 



2. Silver, Argentum, Luna% which is, 



a. Of a white fhining colour. 



b. Its fpecific gravity to water is 11,091 to 

 1000. 



c. It is very tough or ductile, fo that a grain 

 of it may be itretched out to three yards 

 in length, and two inches in breadth. 



melted out of the above-mentioned ores, altho' they have 

 been previoufly di pelted in aqua regia ; and that gold like- 

 wife mixes and difiblves into a regulus; there is the greateft 

 reafon to believe that a third fubltance, which here is a me- 

 tal, mud necefTarily have by its admixture enabled the fulphur 

 to unite wi.h a certain quanlity of gold. Scheffer has given 

 upon this fubject fome very curious and ufeful obfervations, 

 in his Hiftory of the Refining of Metals, inferted in the Tranf- 

 aclions of the Academy of Sciences at Stockholm. It is very 

 remarkable that the Mine-Mafter Henckel, in his excellent 

 Trearife de Appropriation, mould be fo obllinate in denying 

 that marcafite could contain a difTolved gold. 



It is, however, by no means hereby intended to confirm the 

 credulous in their opinion, that the marcafites in general con- 

 tain more gold than what true metallurgies have afTerted ; be- 

 caufe fraud might then perhaps become too common. It is 

 only meant to indicate, that, as no gold is to be expected 

 from marcafues, where no native gold is found in the neigh- 

 bourhood, in the f^me manner no marcafites ought to be de- 

 fpiled, which are found in tracks where gold ores are dug ; 

 but at the fame time care muft be taken not to be deluded by 

 the mention of volatile gold, as it is a notion really contra- 

 dictory and fufpicious, and then there can be no fear of be- 

 ing m:fled. 



I am not perfectly clear, if the gold is really difTolved and 

 indurated, or, if I may fo exprefs myfelf, vitrified in the 

 Shirls (b'chir.kr.rr.ern), provided by this mineral body is 

 meant a garnet fubilar.ee (Sect, ixyiii.) But I have {^en a 

 piece of what is called Shirl, whofe texture was exactly like 

 the Schemoitz blende ; and in this cafe it might perhaps hold 

 ti.e Time contents (Sect, clxxv.) For the other gold ores, I 

 bare net had Ln opportunity of feeing any from thofe places 

 ,vhcre gold is feaxched for and really found. 



d. It 



