ITALY. LETTER XI. Ifl 



ornamental quality, than of real and mineralo- 

 gical differences. I am entirely of opinion, that 

 fherls and the pretended precious ftones are the 

 fame , that the different degrees of their refpec- 

 tive hardnefs are hardly to be determined ; and 

 that the conventional preference of the latter 

 depends only upon their high prices and exqui- 

 fite colours. However, as long as any regard is 

 paid in common life to thefe circum'ftances, what- 

 ever they be, a due regard is to be paid alfo to 

 the difference of their names, fmce it cannot be 

 indifferent to the purchafers, whether a common, 

 or a rare, a foft, or a hard, variety of fherl be 

 fold to them at equal prices *. Thele fcarce and 



hard 



* The author is too good a Naturaliil not to allow the fol- 

 lowing flriftures. Ke fpoke of the gem-like pebbles, inclofed 

 in the lavas, which he very juftly obferves to be different 

 from the fherls on account of their undetermined form, and 

 to be fimilar to the precious ftones on account of their hard- 

 nefs and colour ; 'but immediately after he goes aftray, con- 

 founding them with the fherls, and thefe even with the pre- 

 cious ftones ; which he plainly aflerts to be the fame, not 

 altered by any real and mineralogical principle, but by fome 

 indefinite hardnefs, colour, prejudice, and conventional 

 price. In this confufion of different objects, and in this 

 affertion, he certainly is remarkably wrong, if put to the teft 

 of Natural Philofophy, as plainly will appear by the follow- 

 ing remarks. 



The 



