a ee a a es 
MrcrRoGRAPHIAL. 
Which bringsinto my mind what I long fince obferved inthe fiéry Sparks: 
that are {truck out of.a Steel. For having a great defire to fee: what was. 
25 
left behind, after the Spark was gone out, I purpofely {truck fire over a , 
very white piece of Paper, and obferving diligently where fome confpi-" , 
cuous fparks went.out , I found a very little blatk-{pot no bigger then: 
the point of a Pin, which through a Adicrofcope appeared to be a perfect- 
ly round Ball, looking much likea polifht ball of Steel, infomuch that: 
I was able'to fee the Image of the window reflected from it, . [cannot 
here {tay ( having done it more fully -inanother place ). to examine the 
particular Reafons of it, but fhall only hint, that I imagine it to be fome 
{mall parcel of the Steel, which by the violence of the motion of the 
ftroke ( moft of which feemsto be impreft uponthofe {mall parcels ) is 
made fo glowing hot, that it is melted into a Vitrum, which by the ambi- 
ent Air is thruft into the form of a Ball. : 
~ A Fifth thing which I thought worth Examination was, Whether thé 
motion of all kind of Springs, might not be reducéd to the Principle 
whereby the included heterogeneous finid{eems to be moved 5 or to that 
whereby two Solids, as Marbles, or the like,are thruft and kept together 
by the ambient flnid. mR | 
__ A Sixth thing was,Whether the Rifing and Ebullition of the Water out 
of Springs and Fountains ¢ which lie much higher fromthe Center of th 
Earth then the Superficies of the Sea, from whence it feems to be derived 
may not be explicated by the rifing of Water ina {maller Pipe: For the. 
Sea-water being {trained through the Pores or Crannies of the Earth, - 
as it were, included in little Pipes, where the preflure of the Air has not 
fo great a power to refift its Bhs But examining this way, and finding 
in it feveral difficulties almoft irremovable , I thought upon a way that 
would much more naturally and conceivably explain it; which was by 
this following Experiment: I took a Glafs-Tube, of the form of that 
defcribed in the fixth Figure, and chufing two heterogeneous fluids, fach 
as Water and Oy], I poured in as much Water as filled up the Pipes as. 
high as A B, then putting in fome Oyl into the Tube AC, I depreft the 
fuperficies A of the Water to FE, andB I raifed to G, which wasnot fo 
high perpendicularly as the fuperficies of the Oyl F, by the fpace F 1, 
GE the proportion Of the gravity of thefe two Liquors was as 
to 
_ This Experiment] tried with feveral other Liquors, and particularly 
with frefh Water and Salt ( which made by diffolying Salt inwarm 
Water ) which two though they are nothing heterogeneous, yet before 
they would perfe&tly mix one with another, I made trial of the Experi- 
ment? Nay; letting the Tube wherein I tried the Experiment remain for 
many dayes, I obferved them not to mix 3 but the fuperficies of the frefh 
«was rather more then lefs elevated, above that of the Salt. Now the 
proportion of the gravity of Sea-water, to that of River-water, accord 
Ing to Stevinus and Varenius , and asI havefince found pretty true by 
making trial my felf, isas46.to 45. thatis, 46. Ouncesof the fale Wa- 
as F ter 
