polifh'd; which ſeeming to contradict what has been obſerved by others and by us alſo, that Amber, for inſtance, attracts more vigorouſly if the ſurface be made very ſmooth than otherwiſe, it induces me to conjecture, that, if this Obſervation about Diamonds be true, as ſome of my trials have now and then inclined me to think it, and if it do not in ſome caſes conſiderably depend upon the loss of the (Electrical) Subſtance of the Stone, by its being cut and ground, the Reaſon may poſſibly be, that the great rapidneſs with which the Wheels that ſerve to cut and polith Diamonds muſt be mov'd, does excite a great degree of heat, (which the ſenſes may easily diſcover) in the Stone, and by that and the ſtrong concuſſion it makes of its parts, may force it to ſpend. its effluviable matter, if I may ſo call it, ſo plentifully, that the Stone may be impoveriſh'd, and perhaps alſo, on the account of ſome little change in its Texture, be rendred leſſe diſpoſed to emit thoſe effluvia that are Inſtruments of Electrical Attraction. But as I willingly leave the matter of Fact to further Trial, ſo I do the Cauſe of it, in caſe it prove true, to farther Inquiry.
FINIS.
