2 24 T^aiural Biflory Part I 



neoiis Bodies which are included iri 

 f jiid. it, at the time of its Coalition f . 

 That this is the Cafe of Agates, of 

 Cornelians, of Topazes, and many 

 other coloured Stones ; the Colours of 

 jfeveral whereof, and eVen that of 

 Amber it felf, may by a very eafie 

 procefs, be in great meafure, if not 

 wholly, extracted, and taken from 

 them : and the Bodies of thefe Stones 

 rendered almoft, if not quite, as pel- 

 lucid as Cryftal, without fenfibly 

 damaging the Texture of them. That 

 even the mofi: obvious and ordinary 

 Minerals are not free from this Con- 

 tagion of adventitious Matter: Com- 

 mon Salt it felf, when found natu- 

 rally cryftallized amongft other Mi- 

 nerals and Metalls, in the perpendi- 

 cular Intervalls of the Strata of Stone, 

 being, not only pellucid, as it na-^ 

 turally is when pure and fimple, but 

 white alio, and like the white cry- 

 ftallized Spar : yellow , and nearly 

 refembling the Topaz: blue, and not 

 unlike the Saphire 5 and yet thefe 

 fpecious Bodies, and Gemms as to 

 outward fhew, upon tryal, yield no- 

 thing but meer Salt, with an e>£- 



treraely 



