the Strata of the Vicinity of Bridlington. 208 
this Spring*, can better be discussed: and until this is done, as 
well as the facts of the Spring, stated on longer experience, I 
shall hope to see your pages, sir, more usefully occupied, than in 
prolonging so barren a discussion : at this day, localized facts, 
not closet speculations, on Geological subjects, are wanted, by 
great numbers of your Readers, as well as by 
Your humble servant, 
September 1, 1817. A Constant READER. 
P.S.—I do not feel less obliged to your able and valuable 
Correspondent Mr. Winch, for the important facts of his last 
Letter, in p. 122, than if the same had more directly been stated, 
as corrections of the opinions he formerly gave, when answering 
itty Queries, (in p. 465 of your xlvith volume, p. 101 of vol. xlvii.) 
as also in the Geo. Trans. iv. pp. 73, 74, 75, and 76, corre- 
sponding then, nearly, with those of Dr. Thomson, as to the 
supposed unconformableness, of the masses of Basalt, scattered 
over the northern parts of Northumberland, Whether “ the Basalt 
alternate with the rocks of which the whole district is composed,” 
or not? is an important question of fact, to which my 2nd ques~ 
tion, in p. 12 of your xlviith vol. directly went: and for the 
answer now obtained, I beg most sincerely to thank Mr.Winch: 
—the idle questions, as to whether newest ficetz Trap, or any 
-others of the Geognostie fancies, will apply to the Strata of 
Northumberland, I will readily leave to Dr. Thomson and others 
to decide. 
With regard to the last paragraph of Mr. W’s Letter, I beg 
leave to remark, that what he truly states, as to other sub- 
stances, when seen in contact with Basalt (both of Dykes and 
Strata) sometimes appearing different in quatity, from the ge- 
neral masses of those adjacent substances: is true also, in nu- 
merous instances, which I have seen, with regard to the contacts 
of several other substances filling Dykes, or forming immediate 
alternations of strata, without the intervention of the Wayboards 
or partings, which more commonly are interposed: and, that 
instead of considering, in such situations, the Slate Clay as turned 
into flinty slate, &c. the Coal as being charred, the Sandstone, 
as changed, to a brick red, and the Limestone as rendered highly 
erystalline, &c. by changes wrought on these masses, subsequent 
to their original forination, by heat, communicated to them from 
the Basalt when in amelted or Lava state :—on the contrary, I 
have seen, such abundant reasons for considering all these alleged 
changes, and mpny others, as blendings, or infiltrations of the ° 
component substances of the adjacent masses, coeval with the 
Fed Brighton, in Sussex, had in like manner its wonderful Wells, until 
7602, when their mysteries were cleared up; see Nicholson’s Journal, 
BVO, iii. 65, 
formation 
