The ſpecific gravity of this metal, when pure, is 19,640. Aqua regia diſſolves it; but except the dephlogiſticated muriatic acid, and in certain circumſtances the nitrous, no ſimple acid acts upon it, unleſs it has been previouſly calcined[56]. The quantity of phlogiſton neceſſarily taken away in the ſolution of 100 parts of gold, I eſtimate at about 394; whilſt the ſame quantity of ſilver, loſes by ſolution in the nitrous acid, 100[57]. Gold retains the phlogiſton neceſſary to its metallic form, more obſtinately than any other metal, except, perhaps, platina. It melts and calcines in the focus of a burning glaſs at 1301 degrees of heat.
AURUM nativum (gold native) united to ſilver.
I do not know that gold has ever yet been found perfectly pure.
AURUM nativum (gold native) united to copper.
AURUM nativum (gold native) united to ſilver and copper.
AURUM nativum (gold native) united to ſilver, copper, and iron.
AURUM (gold), mineralized by ſulphur, by means of iron.
Cronstedt Min; § 166. a. Pyrites aureus.
But ſome doubt may be made about the mineralization of gold[58].
AURUM (gold) mineralized by ſulphur, together with ſilver, lead, and iron.
Minera aurifera Nagyayenſis.
I have not yet fully examined this[59].