122 Geological Queries, 



continue red hot, while the platinum is not luminous. On 

 the moment, however, the reverse takes place, and the plati- 

 num becomes luminous, while the iron wire instantly ceases 

 to be so ; nor docs the latter exhibit phosphorescence when 

 the platinum glows. 



I am very respectfully, sir, 



Your obedient humble servant, 

 Surry Institution, Feb, 3, 1817. J. MuRRAY. 



P. S. — I plunged the red hot platinum wire into the vapour 

 of the following essential oils, but did not succeed in maintaining 

 it in this state — Chigonum, nutmeg, lavender and cloves. In 

 the vapour of sulphur I had a lambent phosphorescent flame. 



XXIX. Geological Queries, regarding the Coal Strata, Basaltcs, 

 and Red Marl, of Northumberland and Durham, and on the 

 appearances of' Coal, c^c. in Lincolnshire. By A Corre- 

 spondent. 



To Mr. Tilloch. 



Sir, — J. HE extreme kindness and urbanity of your very able 

 correspondent Nathaniel John IVinch, Esq. in replying, so 

 promptly, in p. 100 of vol. xlvii, to the 5 queries which I had 

 taken the liberty of proposing to him, in p. 12 of that volume, 

 ought long ago to have received my grateful acknowledgements : 

 but gathering from his replies, that the Geological Society were 

 in possession of important communications from him, on the 

 subjects of my inquiries, 1 have abstained from troubling him 

 further; until now, when having read the 1st part of Vol. iv. of 

 their Transactions, I am happy in being able, sincerely to thank 

 and congratulate Mr.W. on having produced [near ^ years ago) 

 beyond comparison the best Paper, for its copious and practi- 

 cally vsefid details, which that Society have yet laid before the 

 public : accompanied at the same time by my regret, that the 

 Society have not tliouglit fit to include also in this part, another 

 Paper, which I leurn that Mr. W. has (more than 9 months 

 ago) presented to them, regarding the east part of Yorkshire. 



Mr. W.'s goodness, and zeal for the advancement of practi- 

 cally useful Geology, will I trust excuse the liberty 1 am taking, 

 in again reviving, and considerably amplifying, some of the sub- 

 jects of my Five Queries, in the page above referred to, viz. 



1st. Are not some of the lower individual seams of Coal, and 

 their floor and roof Measures, of Limestone, &ic. which are 

 worked in the detached part of Durham and NE part of North- 

 umberland, traceable, although perhaps varying much in thick- 

 ness and quality, round the east and south flanks of the Cheviot 



mass 



