MicroGRaPHia, 
45 
which it ftuck by the root F, at the end of which fall Stem was faften- . 
ed-on a Hemifphere, or half a hollow Ball,with the mouth ofiit open from 
the ftemwards, fo that it looked much like a Funnel, or an old fafhioned 
Bowl without a foot. This night, making many tryals and obfervations 
of this Experiment,] met,among a multitude of the Globular ones which 
I had obferved, a couple of Inftances, which are very remarkable'to the 
confirmation of my Hypothefs. Dyes : 
ad 
And the Firft was of a pretty big Ball fattened-on to the end of a fthall . 
liver of Iron,which Compolitum {eemed tobe nothing elfe but a long thin | 
chip of Iron,one of whofe ends was melted into a {mall round Globulsthe | 
other end rethaining unmelted and irregular, and perfectly Ironi: 9 ° > > 
The Second Inftance was not Jef$ remarkable then the Firft; for I 
found, when a Spark went out, nothing but a very fmali thin long fliver 
of Iron or Steel; unmelted at either end. So that it feems, that fome of 
thefe Sparks are the flivers or chips of the Iron vitrified , Others are on- 
ly the {livers melted into Balls without vitrification, And the third kind 
_ are only {mall fliversof the Iron, ‘made red-hot with the violence of the 
{troke givenon the Steel by the Flint. 10 tis wettnt 
He that thall diligently examine thé Phenomena’ of this Experiment, 
will, I doubt not, find caufe to believe, that the reafon [have heretofore 
given of -it, isthe true and genuine caufe of it, namely, That the Spark, 
appearing fi bright in the falline,js nothing elfe but a finall piece of the Steel 
or Flint, but moft commonly of the Steel, which by the violence of the firoké 
is at the fame time fever'd and heatt red-hot , and that fometimes to. fuch 4 
degree , as to make it melt together into a fall Globule of steel and fome- 
times alfa is that heat fovery intenfe; as further to melt it and vitrifie it, but | 
many timesthe heat és’ fo gentle, as tobe ableto make the flrver only red hot, 
which notwithftanding falling upon the tinder (that is only a very curious 
fmall Coal ‘made of ‘the {mall threads of Linnen burnt to: coals and 
chard) it eafily fetsit on fire, Nor will any part of this Hypothefis feem 
firange to him that confiders, Firft, that cither-hammering, or filimg, or 
otherwife violently rubbing of Steel; will prefently make it fo hot as to | 
be able tocburn ones fingers. Next {that the whole force of the ftroke 
is exerted upon that {mall part where the Flint and Steel firft touch: For 
the Bodies being each of ‘them fo'very hard, the puls cannot be far com- | 
municated, that is, the parts of each can yield but very little, and there- 
fore the violence of the concuffion will be exerted on that piece of Steel. 
which is cutoff by the Flint. Thirdly, that the filings or {mall parts of 
Steel are very apt,as it were,to take fire, and are prefently red hot, that 
isthere feems to bea very combuftible fulphureows Body inItonor Stecl, 
Tenly the Air very readily preys upon, as foon as the body is a little vior 
heated. £60 1013 Cheidseus nod sae 
- And thisis obviousin the filings of Steel or Itoncaft through the flame 
of a Candles for even'by that fuddentranfitus of the {mall chips of Iron, 
they are heat red hot, and that combuftible fulphureous Body ts prefent- 
ly prey'd-tipon and devoured by the’ aereal’ incompafling AMenfiraant, 
= Office in this Particular Ihave fhewn inthe Explication of ow 
co . - 
