Mr. Hatchet tV Obfervatiom on Bituminous Sub/lances. 147 



ore of this mine (which is fuppofed to be one of the moft ancient 

 in England) is galena, accompanied by fluor, calcareous and heavy 

 fpars, quartz, blende, calamine, felenite, afphaltum, and the elaftic 

 bitumen, although the latter is now rarely found *. Another 

 fpecies of the elaftic bitumen has within about three years been 

 found in a neighbouring rivulet; but I (hall not at prefent notice it, 

 as I intend firft to defcribe the varieties of that which was firft 

 difcovered, and which refcmbles the cahout-chou. In order to do 

 this with more perfpicuity, 1 fhali defcribe the fpecimens belonging 

 to my collection, according to the mode in which I have arranged 

 them. 



SPECIES the FIRST, 



A, No. 1. 



Elastic bitumen of a yellowifh brown colour, part of which is 

 almoft liquid like petroleum, and adheres to the fingers; the other 

 part is of a darker colour, of a mammillary form, does not adhere to 

 the fingers, and is loft and elaftic. This is on a grey bituminous 

 limeftone, with white calcareous fpar in the figure of hexaedral 

 pyramids, forming that which is called the dog-tooth fpar. 



A, No. 2. 

 Bitumen of a yellowifh brown, partly liquid, and partly elaftic, 

 which, however, adheres to the fingers ; on pale grey limeftone, 

 with cryftals of white fluor fpar, blende, and galena. — On another 

 part of the limeftone are fome globules of bitumen of a reddilh 

 brown, perfectly hard and brittle. 



* I am indebted to the ingenious Mr. White Watfon, of Bakewell, for much infor- 

 mation refpecting the local circumftances which attend this bitumen. 



U 2 A, No, 5. 



