Page:Experimentsnotes00boyl.pdf/575

Rh thoe already mention'd, (as the advantage that Electrical Bodies uually get by having well polih'd or at leat mooth Surfaces,) but the Title of this paper promiing ome Experiments about the Production of Electricity, I mut not omit to recite, how I have been ometimes able to produce or detroy this Quality in certain bodies, by means of alterations, that appear'd not to be other than Mechanical.

Nd firt, having with a very mild heat lowly 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 tranparent Gum almot like Amber, which, as I look'd for, proved Electrical. EX-