'A SYSTEM OF 
i)ut lefs pure, it diffolves copper, iron^* 
zink, and the regulus of antimony : the 
copper is however more eafily dilTolved, 
when k is in form of a calx, as the calces 
of quickfilver and cobalt likewife are. 
7. It unites with filver diffolved in aqua« 
fortis, and with lead diifolved in aqua- 
regia, falling with them to the bottom, in 
form of a white fpongy mafs. This preci- 
pitation, expofed to the lire, kill retains 
the acid, and melts with it into a glalTy 
fubilance, which does not difrolye in water.. 
:8. It is apt to attradt the humidity of the 
air, and to promote the decaying of thofe 
dry fubkances, with which it has been 
united. 
Qo Mixed with the fpirit of nitre, it makes 
the fo called aqua-regia, which is the true 
liquid menftruum for gold. 
This acid feems alfo, on certain occa- 
fions, to have got loofe from' thofe fub- 
ftances, with which it has been originally 
united in the earth : the fal ammoniacum 
natarale at Solfatara in Italy, and the horn 
filver ore (clxxvii.) appear to be proofs of 
this, as they feem to be the produds of 
tune. 
SECT. CXXVIIh 
I. Mixed or fatiated acid of fea-falt, Acidum 
falis heterogeneis fatiiratum, 
A. With earths, "Terris faturatum* 
I. With a calcareous earth, "Terra calcared 
fatiiratum : Sal ammoniacum fixum. 
This fornewhat decays or attracls the 
humidity of the air : it is found in 
abundance 
