57 



TAB. CXXXI. 



PLUMBUM sulphureum ; van haematiticum. 



Haematitic Sulphuret of Lead, or Hamatitie 



Galena. 



Class 3. Metals. Order 1. Homogeneous. 



Gen. 15. Lead. Spec. 3. Sulphuret of Lead. 



Div. 2. Imitative. 



I have heard it remarked from time to time that Galena 

 was to be found in Coal at Matlock in Derbyshire, and T 

 have had a specimen sent me from thence, but it was so 

 full of a decomposing Pyrites that it fell to pieces. 



Lady Aylesford, whose ingenuity is well known, and 

 who has a fine collection of drawings of nearly all the 

 English plants, made by her own hand, was so kind as to 

 exert herself, when in the country last autumn, and 

 procure for me some very curious minerals from Coventry j 

 among which was the specimen here represented. This 

 is not only rare from being among Coal, but for being 

 in this curious haematitic form, a form which has not yet 

 been noticed in Galena, and which will help more perfectly 

 to show the nature of substances that have a regular pri- 

 mitive crystal, passing into, or placing themselves in, a 

 rounding figure. 



The present specimen is radiating from a centre, forming 

 circular and haemisphaerical segments, much resembling 

 Haematitic Iron Ore — tab. 56 and 131. 



This substance is evidently formed of cubes, and has 

 assumed this particular shape from certain circumstances ; 



