On GRANITE. 83 



w Corfe * ', peut-etre y trouvera-t-on quelque jour des to- 

 " pafes." 



M. Patrin has reprefented this fpecies of cryftalization in 

 a different light from that by which I had endeavoured to ex- 

 plain the appearance of this ftone. Pie confiders the quartz as 

 cryftalizing in its natural hexagonal fliape, and thus including 

 bodies of feld-fpar ', whereas I think that it is the fparry flruc- 

 ture of the lad that had induced a certain form upon the quartz, 

 a form which is neither the natural fhape of the cryftalization 

 of that filiceous fubftance, nor an accidental fhape, that had 

 arifen from preceding caufes, but a fliape determined by the 

 concretion of this mixed body cryftalizing from the fluid ftate 

 of fufion. Indeed, I fee nothing in the fpecimens which we 

 poffefs, that can juflify M. Patrin's fuppofition j on the con- 

 trary, almoft every appearance is inconfifhent with it. I fhall 

 mention only one* 



If the figuring caufe, which proceeds longitudinally through 

 the {tone, were that of the filiceous cryftalization, then the 

 tranfverfe fection would exhibit hexagonal figures of quartz, 

 inclofing bodies of feld-fpar. Now, M. Patrin fays, that fe- 

 veral of thofe fides of the hexagons are wanting ; but then 

 what remains fhouldbe conformable to that hexagonal figure of 

 which it was a part. This, however, I think, is not the cafe > 

 and in the fpecimens which I have, the rhombic angles of the 

 feld-fpar feem fo prevalent in the figures, and thefe Hebrew or 

 rather Runic characlers are fo regularly directed by two lines 

 correfponding with the rhombic angle, that I cannot help 

 afcribing this regular figure to that caufe, and not confidering 

 it as produced by the obtufe angles of imperfect: hexagons. It 



L 2 i s 



* I am inclined to believe that this fpecimen, which is here reprefented as coming 

 from Cornea, is no other than the granite of Portfoy which I have defcribed. I imagine 

 that here is only a graphic error, in writing de Corfe, in place oid'Ecoffe. 



