embasement

It is true that now and then, in all Centuries from the Beginning of the World, there have appear’d some Persons of a Nature more refin’d, as if indeed (according to that Phancy of the Old Poets) some Prometheus had made them either of another Metall, or of another Temper, from the Vulgar, utterly above all Mixture with, or Embasement by the common Fashions of this World; who did make it the End of their Lives, by […] multiplying Variety of Experiments on all Bodies, to discover their hidden Vertues, and so to enlarge the Power and Empire of Man.