5^ CECONOMY 



tations of the fea, and lakes, and the vehe- 

 mence of the waves, excited by turbulent 

 winds pulverife Jlones^ as evidently appears by 

 their roundnefs along the Ihore. Nay as the 

 poet fays, 



The hardeft ftone infenfibly gives way 

 To the foft drops, that frequent on it play. 

 So that we ought not to wonder, that thefe 

 very hard bodies moulder away into powder, 

 and are obnoxious like others to the confum- 

 ing tooth of time. 



Sand h formed of freefione^ which is de- 

 ftroyed partly by froft, making it friable, 

 partly by the agitation of water, and waves ; 

 which eafily wear away, dijGTolve, and reduce 

 into minute particles, what the froft had made 

 friable. 



Chalk is formed of rough marlle^ which the 

 air, the fun, and the winds have diffolved, as 

 appears by Iter. Goth. 170. 



T\itjlate earth or humus fchifti Syf. Nat. 511- 

 owes its origin to Jlate^ diflblved by the air, 

 rain and fnow. 



Ochre is formed of metals diffolved, whofe 

 faces prefent the very fame colours, which 

 we always find the ore tinged with, when 

 expofed to the air. Vitriol in the fame 



. man- 



