Page:Micrographia - or some physiological descriptions of minute bodies made by magnifying glasses with observations and inquiries thereupon.djvu/158

Rh spirit of Urine would very readily and easily sink into it, as would also several tinctures drawn with spirit of Wine.

Nor is Marble the only seemingly close stone, which by other kinds of Experiments may be found porous; for I have by this kind of Experiment on divers other stones found much the same effect, and in some, indeed much more notable. Other stones I have found so porous, that with the Microscope I could perceive several small winding holes, much like Worm-holes, as I have noted in some kind of Purbeck-stone, by looking on the surface of a piece newly flaw'd off, for if otherwise, the surface has been long expos'd to the Air, or has been scraped with any tool, those small caverns are fill'd with dust, and disappear.

And to confirm this Conjecture, yet further, I shall here insert an excellent account, given into the Royal Society by that Eminently Learned Physician, Doctor Goddard, of an Experiment, not less instructive then curious and accurate, made by himself on a very hard and seemingly close stone call'd Oculus Mundi, as I find it preserv'd in the Records of that Honourable Society.

A small stone of the kind, call'd by some Authours, Oculus Mundi, being dry and cloudy, weigh'd 5 Grains.

The same put under water for a night, and somewhat more, became transparent, and the superficies being wiped dry, weighed 6 Grains.

The difference between these two weights, 0 of a Grain.

The same Stone kept out of water one Day and becoming cloudy again weighed, 5 Graines.

Which was more then the first weight, 0 of a Grain.

The same being kept two Days longer weighed, 5 Graines.

Which was less then at first, 0 a Grain.

Being kept dry something longer it did not grow sensibly lighter.

Being put under water for a night and becoming again transparent and wiped dry, the weight was, 6 Grains, the same with the first after putting in water, and more then the last weight after keeping of it dry, 0 of a Grain.

Another Stone of the same kind being variegated with milky white and gray like some sorts of Agates, while it lay under water, was alwaies invironed with little Bubbles, such as appear in Rh