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If we can ever bring Spar, after Solution, to recryſtallize, as Salt; we ſhall ſee all Things explained in this Particular. 'Tis what I have tried four Years, with poor Succeſs; and I have now, requeſted the ableſt Chymiſt that we have, to join with me in the Attempt. What may ariſe under his experienced Hand, I know not: All I have found is, that the ſwifter the Fluid is evaporated, the coarſer is the Matter left behind; and the more Length of Time is given, the nearer it approaches to a Promiſe of Cryſtals.
I think when this ſhall be accompliſhed, we ſhall find all Spar to be but one Thing; differing only according to the other Matters mixed with it. 'Tis ſaid, the Selenite powdered and mixt in Water affords Cryſtals; and Kabler gives the Authority of an eminent Metallurgiſt for it: With me neither has this ſucceeded yet; But I have no Deſpair; and tho' it never ſhould ſucceed with me, it may with others: When that is ſeen, the other, more important as it is, need not be ſuppoſed impoſſible.
Nothing is more familiar than the Production of what it is the Cuſtom to call, Selenitical Salts; Urine affords them; and ſome Preparations of Sulphur; but to recryſtalize Selenite is, to produce, from a clear Fluid, pellucid dodecahacedral Rhombs, flexile, not elaſtic, and not ſoluble again in Water: And he who ſhall effect this, need not deſpair of recryſtalizing alſo Spar.
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