The Natural Hiflory Part IIL 



denfe Marble and Sand-ftorie for thefc 

 give Admiffion to it, though in lefler 

 quantity, and are always found farora- 

 ted with it; which is the reafbn that 

 they are,fbfter, and cut much more ea- 

 fily , when firfl: taken out of their Beds 

 and QuarrieSj than afterwards, when 

 they have lain fome time expoled to 

 the Air, and that Humidity is evapo- 

 rated. 



That this T'apour proceeds up dire£l:- 

 ly towards the Surface of the Globe on 

 all fides, and, as near as poffible, iji 

 right Lines, unlefs impeded and di- 

 verted by the Interpofition of Strata of 

 Marble, the denier forts of Stone, or 

 other like Matter , which is fb clofe 

 and compaQ: that it can admit it only 

 in fmaller quantity, and this very (low- 

 ly and leifurely too. 



That when it is thus mtercepted in 

 its palfage, the Vapour^ which cannot 

 penetrate the Stratum diametrically ^ 

 fo?ne of it glides along the lower Sur- 

 face of it, permeating the horizontal 

 Interval which is betwixt the laid denfe 

 Stratpm and that which lies underneath 

 it : -^he refi paffing the Interftices of the 

 Maf^ of the fubiacent Strata^ whether 

 they be of laxer Stoae^ of Sand, of 



Marle^ 



