154 AVOYAGETO Book VII. 



ficuk to account for the formation of thefe maffes of 

 filvcr> in a barren and moveable fand, remote from 

 any ore or mine. Two conjednres may, however, 

 be offered. The hrft by admitting the continual 

 reprodu61:ion of metals, of which there are indeed here 

 fo many evident proofs ; as the matrices of gold and 

 fiiver, met vnth in many parts of this kingdom. Nay 

 the very mines themfclves, after being long forfaken, 

 have again been worked v;ith great advantage but 

 the fl^eietons of Indians found in old mines, and 

 covered with fibres of filver, and the inward parrs 

 alio full of the fame metal, feem to put the matter 

 beyond difpute. If this be admitted, ic is natural to 

 conclude, that the premordiai matter of filver is firft 

 fiuid, and when it has acquired a certain degree of per- 

 fection, fome parts of it are filtrated through the pores 

 of the fand, till flopping in a place proper for corn- 

 pleating the fixation, they there form a folid congeries 

 of filver; and being joined v^ith thofe earthy particles 

 they colleded in their courfe to the place where they 

 were abforbed by the pores of the fand, confolidated 

 With the filver. 



Tho' this conjedlure be not deflitute of probability, 

 yet I am more inclined to embrace the fecond, as it 

 is, in my opinion, more fimple and natural. Sub- 

 terraneous fires being very common in thefe parts of 

 America, as I have already obferved in fpeaking of 

 the earthquakes, their adivity is doubtlefs fo flrong 

 as to miClt any metals deponted near the places where 

 they begin j and to communicate to them a heat 

 foi^cient for keeping them a long time in a flate of 

 fufion ; and hence a portion of niver thus melted ne- 

 ceifarily fpreads, and introduces itfelf through the lar- 

 ger pores of the earth, and continues to expand itfelf, 

 till being beyond the reach of the heat, it fixes, and 

 re-afTumes its former confiftency, together with other 

 hetei-ogeneous fubRances coUe^led in its paifage. 

 To this hypGthefis, two objedions may be offered ; 

 ■ ' one 



