224: Dr. Cooper on ¥ olcanoes 
Basalté burn contiguous substances.. M. Voight in: his 
mineralogical journey to the mountains of Hesse, says that. 
between the ‘coal and basalt isa thin argillaceous layer ; but 
the coal has manifestly been acted on by the heat of the in-: 
cumbent Lava. Breisl. § 703... Sand stone acted on by 
and converted into Jasper for ten feet, by pervading and 
superincumbent basalt just like that of the iron surfaces, 
Haussman. Ib. § 704. Same phenomena observed in an 
agillaceous: stratum, by Messrs. Conybeare and Buckland. 
{b... Also by M. Hoff near Suhl: and by Prof. Playfair at 
Salisbury Craig. ‘The same circumstance observed also by 
Whitehurst in relation to the Derbyshire Toadstone. See 
Theo. of the Earth, 197, 198... The same observations by 
Brande as to the coal at Fairhead. Cat. of the Min: of the 
Roy. Inst. p. 184, 185. ” 
Basalt burning coal and also contiguous limestone, 4 Geol. 
trans. 102. See also to the saine purpose, 3 Geol. trans. 
99, 201, 205, 213, 257. Sandstone converted. by Basalt 
into Hornstone and black shist into. black lydian stone. Ib. 
To the same purpose Brande’s Catalogue, p. 171, 179, 184. 
Hard chalk converted into granular marble for upwards 
of ten feet. 3 Geol. tr..172.., So, of Lias Limestone. Ib. 
213. Coal deprived of its bitumen and,eharred through a: 
layer of interposed sandstone. Ib. 257... -Limestone chryss 
tallized by the Cleaveland Dyke. Bakewell, p. 272. . The’ 
same effect produced artificially by Sir James Hall :, Edin. 
The basalt dyke on the Yorkshire coast, forty feet thick, 
running sixty or seventy miles on the surface from Cockfield, 
fellin the County of Durham, to the river Tees, near Pres- 
ton, Lancashire...Then entering Cleaveland in Yorkshire, 
is traced to the coast where it is lost about Blea Hill, near. 
the upper end of Harewood Dale. It rises perpendicular- 
ly to the strata. It is found in oblong. blocks or ‘masses 
parallel to one another lying inthe vein.’ The fracture is 
rough, granular, of a blue colour, containing shining crys- 
tals. The seam of coal in Durham, where the dyke cuts 
it for some feet distance, is turned into a sooty substance, 
which becomes a-cinder, as. the distance from the: whin- 
stone, (Basalt,) increases, until at fifty yards it assumes the. 
appearance of coal, 214 Tillock’s Mag. for March, 1818. 
Greenstone, deprives contiguous coal of its bitumen, even 
