A SYSTEM OF 
I 
fubje(5l to the fame alterations, and we llkcwife 
outlive the greateft part of them, therefore we 
treat them with more eafe and conveniency ; 
whereas the changes which the mineral kingdom 
undergoes, are hidden to us, and require many 
centuries to compleat them. 
I cannot fuppofe the mineral bodies to be pro- 
duced by feeds, for want of proof*, and I do not 
know why the metals fhould have any preference 
in that refpeft. Native or virgin copper and 
filver are produced in the fame manner as the 
flaladites. The water carries along with it the 
invihble particles of lime, copper, or filver, and 
depofits them upon other fubjedls, either by 
means of an attractive power in thefe, or by fome 
alteration in itfelf, occafioned by its motion. The 
precipitated particles are, at the beginning, very 
eafily feparated ^ but in procefs of time they co- 
here very firmly, as is evidently feen in the na- 
tive precipitated or Ziment-copper which, after 
it has been fome time taken out of the water, is 
partly malleable. The figure which native gold 
and filver have in their rocks or beds, does not 
prove any more than do the metallic iron’s or cop- 
per’s accreting into a mofs-like form in the poor 
or rich roafted ores or reguli at the furnaces ; it 
gives us rather an idea, how thofe accidents hap- 
pen, merely by the fhrinking and the fudden cool- 
ing of their furfaces : and we can then alfo begin 
to conceive fomething of the reafon why cryftals 
are found in a pebble form, or in loofe nodules, as 
tht petrified melons of Mount Carmel^ and the Ita- 
lian iron ores, in form of balls, &c. without 
wanting to have recourfe to the fuppofidon of a 
* Called Ziment-copper from its being lirft noticed in a 
vitriolic water called ziment, at lierrengrund in Hungary^ 
P. C. 
melting 
