78 Copper obtainedfrom Iron , 
which fhew exadly the different Sides there¬ 
of. It confifts of ten Planes. 
If a Piece of Iron be left for fome fhort 
Time in a Solution of blue Vitriol* its Sur¬ 
face will appear of a Copper Colour, and 
is really covered with Particles of Copper, 
either precipitated upon, or attracted by 
the Iron, to which they firmly adhere, and 
whofe Pores they feem to fill. This may 
ferve to fhew after what manner fome 
Springs of Water are able to perform what 
is ufually called a Tranfmutation of Iron 
into Copper; which indeed is nothing more 
than a gradual Diffolution of the Iron, whofe 
Place becomes as gradually fupplied, and 
its Figure affirmed by the minute Particles 
of Copper floating in the faid Water: fo 
that, although a Mafs of Copper may be 
found, after a Length of Time, inftead of 
a Mafs of Iron, there is no Tranfmuta¬ 
tion in the Cafe. The whole Fad feems 
only to imply, that the minute Particles of 
Copper wherewith the Water is ftored, be¬ 
ing much fmaller than the Pores or Inter- 
dices between the Particles of Iron, do firfl 
of all get into and fill up the faid Interfaces. 
We have then a Mafs compounded of Iron 
and Copper; but the Iron Parts thereof 
becoming gradually corroded and wafhed 
away by the Water (the mineral acid Salts 
it contains rendering it a Mendruum there- 
their Places are immediately occupied 
