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nearly as salt is dissolved by water. On adding to thiscompound a little powdered charcoal, or barely stirringit with an iron rod, the lead revives and falls to thebottom ; and as the sand had thus been in contactwith every part of it, the gold will probably be extractedfrom every part, or at least more effectually than by theother methods. In this way it will be proper to mix somealkaline fait with the litharge and sand; partly, to pro-mote the dissolution of such portion of the sand as floatson the top of the ponderous metallic preparation; andpartly, to continue the fluidity of the scoria after the re-vival of the lead. The crucible may be made of Stur-bridge clay, which seems to be one of the best, of thecommon materials, for resisting glass of lead in fusion.It appears to have been on a process of this kind, thatLecher's proposition to the States of Holland was founded,for extracting gold with profit from common sands j it isplain from his account of this affair in his mitiera arenaria,that he vitrefied the sand with glass of lead, or litharge,and he expressly mentions in one place the precipitationof the lead from the glass by iron : he used also an addi-tion of silver, in great proportion, for imbibing the gold,and thus required a vast capital for establishing a work inlarge; but where the lead is to be revived, the silver israther detrimental than useful ; for the gold and silvercontained in the sand are imbibed by the lead, and theadditional silver occasions an enormous expence of aquafortis for dissolving it in order to the separation of thegold. Whether, with this reduction of the expence, ofwhich Lecher himself seems to have had some idea, theprocess might be practicable to advantage, or whethersome earthy bodies might not be an useful auxiliary forpromoting the fusion of the gold sands, may deserve fur-ther enquiry : one kind of earth is frequently observed to5 bring