268 NATIVE COLD PUST* 



were the primitive origin of their dissemination amid the 

 strata, it certainly could have happened only at some very 

 remote period of the grand disruptions, that have takeiit 

 place on the surface and exterior strata of our globe. But 

 these revolutions, of which we have no records, are buried 

 in the night of time. For we shall see, that strata, which 

 furnish gold dust, are found at a considerable depth in some 

 bills, equally remote from mountains capable of furnishing 

 it, and from rivers that could force it from its native situa- 

 tion. Consequently it could have mingled in them only at 

 a very distant period, when the strata of the hills assumed 

 the arrangement they have at present, namely, at the time of 

 their formation. 



t*histheopi- Such too has been the opinion of several naturalists of 



nion of many, our country, and I should be guilty of injustice to them, 

 if, in collecting fresh proofs tending to support their hypo- 

 thesis, I omitted the mention of their valuable works. Ac- 



DeRobillant. cordihgly I shall quote Mr. de Robillant, who, speaking of 

 the gold dust found in the sands of the Oreo, says very 

 positively: " this river carries along gold, which the people 

 of the country observe only below the bridge down to the 

 Po ; which confirms the opinion held by the people best ac- 

 quainted with the natural history of the country, that it is 

 from the gullies and hills that this gold dust is washed down 

 into the river by the rapidity of the water during storms---^. 

 This valuable metal does not come from the high mountains, 

 since none is found above the bridge, but it originates frota 

 the washing of the red earth, of which most of these hills 

 and plains are composed, and which in stormy weather is 

 carried down into the principal riverf, 



Balbo. Mr. Balbo generally adopts the explanation of Mr. de 



Robillant respecting this species of native gold, in his 

 learned Memoir on the auriferous sand of the Oreo. " Every 

 one," says he, " knows, that gold dust is collected in the 



Oreo But I do not believe it is equally known, that 



gold is found, not in the bed of the river alone, but to the 



* See a geographical Essay on the continental Territories of the King 

 cf Sardinia, by de Robillant, in the Memoirs of the Royal Academy of 

 Sciences of Turin for the years 1784,5, Part II, p. 234. 



fib. p. 268. 



distance 



