Remarks upon two late ingenious discourses the one, an essay touching the gravitation and non-gravitation of fluid bodies, the other, observations touching the Torricellian experiment, so far forth as they may concern any passages in his Enchiridium Metaphysicum / D. Henry More.

Upon Chapter the Eighth.

REMARK the Seventeenth.

OUR Authour reasons pas∣sing-well against a free per∣meation of the Aether into the Glass-Tube derelicted of the Quick-silver, because the Quick∣silver then would subside to the bottom, as when there is but a hole at the top of the Tube no bigger than a Pins point, because then the Air he thinks may come in freely, so if the Aether could come in freely through the pores of the Glass, the Mercury would subside in that case too. But that the subtiler parts of the Air or Aether cannot upon occasion (though not so freely) penetrate the pores of the Glass, His Ar∣guments for this Assertion seem to me altogether unsatisfactory. For if I understand him aright, the first thing he offers to prove

it by, is, That if they could pe∣netrate at all they would pene∣trate freely, and then the for∣mer Inconvenience would return. The second is a denial, or suppo∣sal that there are no such pores in Glass as any such smaller Particles can go thorough. But to the first I answer. That though the pores of the Glass be pervious enough to the Aether or subtiler parts of the Air, yet the R••ni∣tency of the natural consistence of the Air will not for-go them but by some force, and a less pres∣sure or force than of a column of Quick-silver of about 30 inch∣es high will not prevail, any a∣bove it will. To the second, That in my first Remark I have hinted that (part 4.) which will sufficiently prove that there are pores in the Glass as well as par∣ticles subtiler than the Air to pass through them, as is appa∣rent in the direction of the rays

to one point through a Burning-glass, against what our Authour here declares that there is only a vis, virtue or vigour corporeal, no substance that penetrates the Glass. For as bodies are only tangible, so they are only reflex∣ible and refractable; To which you may add, that the lightness and frangibleness of Glass are far∣ther Indications of its porosity. These things are so plain to the unprejudiced that it is needless to insist on them.

REMARK the Eighteenth.

And yet we may use a further confirmation of the subtiler parts of the Air passing the pores of the Glass, from the Authours own concession, p. 128. l. 18. that they pass not through the Mercury, as he conceives they do in the inverting a Glass-Tube of Mercury on the free Air, in

which case he observes bubles ascending in the Mercury as it de∣scends; but there being no such tumultuary motion of the Mer∣cury in the Torricellian Experi∣ment, he concludes, no parts of Air pass through the Mercury into the Tube. And therefore say I, it is the plainer case they pass through the pores of the Glass only in this experiment.