( ?79 ) ; 
in fufion without fparkling, but at laO: it fparkles with 
the fame brisknefs as Iron itfelf 5 and when withdrawn 
from the Focus, appears nothing different from melted 
Iron. , . - t T 
It appears from thefe Experiments, that Iron con* 
tains a fulphar or oily Subftance, that renders it brighr, 
malleable, and eafy to melt. 
That this Sulphur is raifed by the Fire of the Sun^ when 
the Metal is for fome time held in tufion in the Focus of 
the Glafs. 
That this fame Sulphur may be raifed by the Flame of 
common Fire, which tho’ not ftrong enough to melt the 
Iron, yet is able to reduce it to an Efchar or fort of 
Riift. , . 
That Iron deprived of this fulphurous part, melts into 
a Regulus, or brittle and friable Mafs, in colour much 
like Antimony. 
That if one can hold a fufficient quantity of this Matter 
long enough in the Focus by itfelf, without melting or 
mixing with the Body that contains it, it perfe<5Uy vitri* 
fies. 
That this Glafs or metallick Regulus, with the help 
of a little Oil, returns to its former ftate of a Metal 
That it reaffumes this metallick Form upon Charcoal, 
by drawing thence this oily Subftanee. 
That, in (hort, this oily part contain’d in the Coal, is 
■ little di&rent from the Sulphur of Iron, Neverthelefs 
we muft imagine it to differ in fome particulars, in that 
melted Iron that has been faturated with it, crackles and 
fparkles very much when melted again upon the Stone or 
Coppd. 
Iron being the only Metal in which I have obierved 
this fparkling, I take it to be a Property peculiar only to 
Iron and not to any other Metal Perhaps we may attri- 
bute it to the vitriolick Salt that this Metal fo plentifully 
abounds with, which is very greedy of Sulphurs. 
L 1 1 2 To 
