46 O F E A R T H S. 



-with Aquafortis. In the fire it acquires a conficlcrablc hardnefs, 

 and a bright bluifh-grey colour. 



The WelJIj, in Merioneth/hire^ call it Nod du, which in their lan- 

 guage fignifies a black mark. They find it near the top of Cay 

 Avon, a high hill near the village of Dynafmondhivye; in that 

 county, and is on record in an old Briti/Jj proverb for being one 

 of the three remarkable things of that place. They ufe it in 

 marking their fheep. They prepare it by pounding it in a mortar, 

 and moiftening it with water, and then making it into balls. 



It is very much ufed in painting by the Germans and Saxons. 

 The former are faid to find it at Dietfurterriet t in the territory of 

 Pappenheim. They prepare it by carefully warning away the im- 

 pure parts, and make it up into flicks or rolls like Indian ink. The 

 latter call it, Schiefer Schwartz, and prepare it in like manner. 







In our northern counties it is commonly known by the name 

 of Colloiv or Killoiv ; by which name it is called by Dr. Wood-ward 

 and Dr. Merret (m). 



A light, friable, gold coloured ochre, the ochre of Theophraftus 

 (p} t is found in concreted nodules among the Geodes and loofe 

 iron-ftone on the edge of the brook at Simonburn, and other places 

 in Tynedale\ not unfrequently. It is of a lax texture, and of a 

 dufty furface when broken, colouring the fingers with a bright 

 gold yellow, extremely light and fine, like an impalpable or 

 farinaceous powder. It adheres firmly to the tongue, melts freely 



(m) Killoia molliufcula. The fofter killow. Wooclw. Meth. of Fofs. p. 2. No. 5. et 

 Cat. C. a. 26. et 27. Merret. Pin. p. 218. 



(n) Ochra aurei Colon's. Da Coda. Nat. Hift. Foil", p. 99. No. 8. 

 Ochra levis aurea friabilis, quas Ochra Theophrafti. Hill. Hift. Foff. p* 52. Woodw. 

 Cat. C. a. 3. 



in 



