Queries and Answers, 191 



** the beds in the day-slate belonging to the transition class of rocks (?). 

 More abundantly in the slate-clay or shale of the independent coal-form- 

 ation." He adds, that ifi England and Scotland it is abundant " in many, if 

 not most of the coal deposits ; " and says that " crystals of blende, galena, 

 and yellow copper are observable in the interstices of the amorphous from 

 Wednesbury, in Staffordshire," 



H. D. will find plenty of ^tites in the banks of the road between 

 Whitehaven and St. Bees in Cumberland ; as well as in other vicinities of 

 the coal measures. Also in the beds of the London clay, as at Logham 

 in Suffolk; in the plastic clay, as at Reading in Berkshire, and Logham 

 in Suffolk ; and in the sands of the crag, as at Tattingstone, in Suffolk, 

 W'here they are not only very abundant in the upper part of the formation, 

 but of an extraordinary size. I mention these latter places from personal 

 observation only. — W. B. Clarke. East Bergholty Suffolk y September 7. 

 1830. 



A Black Mineral Substance found in Clay. — This substance was dis- 

 covered in the large excavation now being made to connect Lake Lothing 

 with the sea at Lowestoft ; being part of the plan for making Norwich 

 a port. It was found about 8 ft. below the level of the ground ', the first 6 

 of which are peat or decayed vegetable matter of comparatively recent form- 

 ation, it is supposed, as among it we find parts of oak and chestnut trees, 

 which retain their natural hardness ; below this, about 1 ft. of an irregular 

 stratum of sand or gravel ; then a strong blue clay, thickly interspersed in 

 places with small nodules of chalk. The stratum of clay is very irregular 

 in this place, about 6 ft. perhaps ; and, below that, sand to a greater depth 

 than has yet been excavated. The black substance was found about 1 ft. 

 in the aforesaid cla}^ in an irregular mass about the size of a man's open 

 hand, laid horizontally. When first discovered it was in softness and 

 elasticity resembling strong glue when first cold ; breaking with a similar 

 fracture, but more easily. When cut into slices as thin as paper, which 

 was easily done with a sharp knife, it was semitransparent, and appeared 

 of a rich brown colour, which it also showed when rubbed on paper. By 

 exposure to the atmosphere it gradually hardened as it now appears ; at the 

 same time shrinking to one eighth of its former bulk ; a piece cut into a 

 cube exactly half an inch on the side, shrinking to a cube a quarter of an 

 inch on the side. When submitted to the action of fire, it emits neither 

 flame nor smoke, but leaves hard white ashes. Neither water, spirit, nor 

 acids have any effect upon it. From its contiguity to the peat, it might be 

 thought an incipient formation of coal ; but the total absence of bitumen, 

 or inflammable principle, seems to contradict that idea. — G. M. Lynn 

 Regis, Dec. 1. 1830. 



The substance sent is anthracite, blind coal, Kilkenny coal, or glance 

 coal. There are three varieties; and that sent appears to be the con- 

 choidal antliracite of Jameson. Its colour is iron-black, sometimes tar- 

 nished on the surface with a splendent metallic lustre ; fracture conchoidal, 

 with a pseudo-metallic lustre. It is brittle and light ; it yields no flame, 

 and leaves whitish ashes ; it is found in the newest floetz formations at 

 Meissner in Hesse and Walsall in Staffordshire." The other two varie- 

 ties are slaty anthracite and columnar anthracite. — Cond.^ 



The Weather; in reply to Mr. Main. — Sir, In reply to your very 

 intelligent correspondent Mr. Main (Vol. III. p. 487.), I would, in the first 

 place, beg to offer him my best acknowledgements for his very judicious re- 

 marks on my meteorological queries (Vol. 11. p. 177.). With regard to the 

 differential thermometer, it was first invented by Professor Leslie of Edin- 

 burgh, and called by some a thermouietric h^^grometer. Its use is to mark 

 the difference of temperature produced by evaporation, and in its simplest 

 form may consist of two ordinary spirit of wine thermometers, graduated 

 on the same principle. One of the balls is covered with tissue paper, the 



