52 CECONOMY 



fand, the more eafily it concretes. But if an 

 ahaline clay chances to be mixed with the 

 fand, the freeftone is generated more readily, 

 as in the freeftone called cos friatilisy particulis 

 argillo'glarenjisy S. N. i. i. 



The flinty S. N. 3. i. is almoft the only kind 

 oi ftone^ certainly the moft common in chalky 

 mountains. It feems therefore to be produced 

 from chalk. Whether it can be reduced again 

 to chalky i leave to others to inquire. 



Stala5litesy S. N. ^'^. i. or drop-ft one is com- 

 pofed of calcareous particles, adhering to a dry 

 and generally a vegetable body. 



The incruftations S. N. 32. 5, 6, 7, 8. are 

 often generated, where a vitriolic water con- 

 nefts claiey and earthy particles together. 



Slate by the vegetables, that are often in- 

 clofed in it, feems to take its origin from a 

 marfhy mould. 



Metals vary according to the nature of the 

 matrix, to which they adhere, e. g. the py- 

 rites cupri Fahlunenfis contains frequently /«/- 

 phur^ arfenicy iron^ copper ^ a little gold^ vitriol^ 

 alum, fometimes lead ore, filver and z/wc^.Thus 

 gold, copper, iron, zinck, arfenic, pyrites, vitriol ^ 

 come out of the fame vein. That very rich 

 iron ore at Normark in Vermelandia, where 

 4 « 



