OF STONES. 8 9 



found, but rarely, on the fhore of the Coquet, above Rothbury, in 

 the cryftalliform flate ; from which I have a fine one, of a 

 pebble-like figure, with many pyramids of three quarters of an 

 inch in length, rifing from a bafe of purple cryftal, their tops 

 hid from the eye by an irregular fimiofe cruft of the fame colour ; 

 their exterior fides and angles confpicuous, and femipellucid ; 

 affording a pleafing fight between two fuch covers at top and 

 bottom, 



Of Calculi oi 4 pebbles, of a cruftated ftrticturc, capable of a 

 fine polim, we have the following forts ; the edges of the crufts 

 forming the elegant and beautiful figures we call veins, 



1. A pebble with purple and white crufts ; the purple of two 

 different degrees, a lighter and deeper j fome of the crufts fo 

 broken at one end, as to mew the manner of its formation. It is 

 an inch and a half long, and an inch in diameter. From the 

 Ihore of the Tiveed* 



2. A mixt red and yellow pebble, with blue, Carmine, and pearl- 

 coloured crufts ; an inch and a half long, and an inch in diame- 

 ter. From the Ihore of the JBoiv-mont, fo called from its arcuated 

 or bending courfe under the mountains. 



3. A pebble with crufts of a flefh-colour, and white ; the white 

 central cruft broken fo as to fhew the manner of its formation. 

 From the fame ihore. 



4.. A pebble of a deep brown, With crufts of a light brown, 

 white, and a pearl-colour ; two inches long, and an inch and 

 a half broad ; ponderous. From the fliore of the Coquet^ above 

 Rothbury. 



VOL. I. ft $. A 



