Embasement

1664, Richard Davis, “The Publisher to the Reader” in Robert Boyle, Some Considerations Touching the Usefulnesse of Experimental Naturall Philosophy, Oxford, 2nd edition, 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.

1744, Robert South, Posthumous Sermons, Sermon XIX in Sermons Preached upon Several Occasions, Oxford: Clarendon, 1823, Volume 5, p. 360, […] if the very condition of the creature gives it such a shortness, and hollowness, and disproportion to the desires of a rational soul, even in the most innocent and allowed pleasures; what shall we think of the pleasures of sin, which receive a further embasement and diminution from the superaddition of a curse?

There is dross, alloy, and embasement in all human tempers; and he flieth without wings, who thinks to find ophir or pure metal in any.