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of Electricity
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thoſe already mention'd, (as the advantage that Electrical Bodies uſually get by having well poliſh'd or at leaſt ſmooth Surfaces,) but the Title of this paper promiſing ſome Experiments about the Production of Electricity, I muſt not omit to recite, how I have been ſometimes able to produce or deſtroy this Quality in certain bodies, by means of alterations, that appear'd not to be other than Mechanical.
EXPER. I.
ANd firſt, having with a very mild heat ſlowly evaporated about a fourth part of good Turpentine, I found, that the remaining body would not, when cold, continue a Liquor, but harden'd into a tranſparent Gum almoſt like Amber, which, as I look'd for, proved Electrical.
EX-
