O F S T O N E S. - 99 



them as to be "taken by fome people for marine remains ; confid- 

 ing of an opake, tabulated, glofly quartz, the Feld-Spath of the 

 German authors, which always affects angular figures, approach- 

 ing oblong fquares, cubes, and parallelepipeds, in its cryftalliza- 

 tion, both in porphyry and granite. I have a beautiful nodule 

 of it from the fhore of North Tyne, and others from the Ihore of 

 the brook at Simonburn. It is capable of an elegant polifli ; the 

 ground-colour of a deep grafs-green. It is the Ophites of the An-* 

 tients (f). They had it from the Upper Egypt, near the city of 

 Memphis, from which they alfo called it Memphites (g). It had its 

 firft name from its imaginary virtues againft the bites of ferpents 

 and from the refemblance of its fpots to thofe on the fkins of 

 fome of thefe reptiles. Small Teffellx of mofaic pavements have 

 been found of it in the ruins of Italy, but no vafes, ftatues, and 

 other works of value, either Grecian or Roman. The blocks of it 

 now found in the ruins of Egypt, are not of any great fize, from 

 whence it is thought, that the ftrata of it were not confiderable 

 for extent and depth. 



Stones compofed of fmall pebbles, and anfwering the teds of 

 cryftal, are fometimes found on the more of North Tyne ; from 

 which I had the two following forts. 



\Jl. Of a dark brown ground, thick fet with pebbles or concre- 

 tions of a bright and deep red, a bluifh-white, black, a pale 

 yellow, and a yellowim-green, forming a beautiful variega- 

 tion. 



(f) Phorphyrites faturate 4 viridis maculis magnis oblongo-quadratis ex viridi albentibus 

 notatus, f. Ophites niger antiquorum. Da Co/la. Hift, FgfK 287. No. 2. 



( s ) Pl'tn. Hift. Nat. 1. 36. c. 7. 

 Serpentine Aotico, Italice. 



O 2 Idly. 



