( 4°6 ) 
lating to the Affair of Metals j wherefore I (hall only 
add, that thefe criftalline Concretions exert a flrong 
Attraction on many metallick Subftances. As in Fig . 7. 
A the Spar has attracted the three Portions of Lead B. 
and in Fig, 8. the Criftals C have attracted the Copper 
D, and are attracted by the Lead E. 
The fulfhureo-faline Particles, with which, as I 
obferved, the Waters are frequently faturated, are found 
to be either of a 1 vitriol ick or an arfenical Nature : The 
firfl conflantly, if pure, concreting into white Cubes re- 
fembling Grains of Silver, while the arfenical Sulphur 
concretes into yellow Cubes like Grains of pure Gold. 
Both thefe are' by the Miners term’d Mundick. 
Thefe fulphureo-f aline Subfiances feem directed in 
their Concretions by a plaftick Particle, in the fame 
Manner as the Criftals above-mention’d ; and, like them, 
upon the fame Principles, are found fimple or compound. 
In their Sides you may obferve the Concretion forms it 
felf like Threads, which in three Sides run in different 
Directions, but are always fimilar in the oppofite Sides. 
Fig. 9. fhews one of thefe Cubes, A the parallel 
Threads. 
Fig. ic. {hews another of thefe Cubes, from whofe 
Sides arife fmall Segments of Cubes C. 
But this plaftick Tower feems to be weaken’d or 
deftroy’d, in Proportion, as this fulphureous Matter is 
more or lefs intangled with metallick Subftances. 
Thus in Fig . 11. the plaftick Particle feems for a 
while to have exerted its Power in the ufual Manner, 
till the advening Matter grew intangled with a fmall 
Quantity of Copper, after which it feems only to have 
exerted its attraffive but not its plaftick Tower . 
And 
