854 Mr. Farey’s Introductory Remarks, to 
of perversion: but having since been charged by Mr. H. with a 
niisrepresentation to favour my own views, I beg you to make 
room for a few quotations from his paper (vol. xlv. p. 463), which 
I conceive to warrant my statement. 
After submitting sulphat of iron to a heat sufficient to drive 
off a portion of the acid, he says, ‘“¢ Water being added, the super 
silphat was in solution, and some oxide precipitated.” Again, 
he says, that the sulphat and sub-sulphat of mercury “ ave not 
perfect salts, but peculiar mixtures of the super sulphat with the 
oxide.” And, tastly, that as the sulphat of mercury is acid when 
water is added, ‘ it must in the dry state le an acid salt with an 
excess of oxide mixed with iu.” 
It is time to quit this subject, which must have become tedious 
to your readers, without affording them any real information» 
my design was, in the first place, to discover truth; to ascertain 
whether H.’s conjectures were founded on reason; and lastly, to 
exculpate myself from a charge of misrepresentation. 
I am, sir, 
Most obediently yours, 
Burton Crescent, May 15, 1816. G. S. 
LXXII. 4A Letter from Dr. Wi11am Ricuarpson to the 
Countess of GosForD (occasioned by the Perusal of CuvrER’s 
‘© Geological Essay’’), describing the Arrangement of the 
Srrata for 60 Miles an the South and as many on the North 
of Gosford Castle; in Armagh County in Ireland. _Com- 
municated by Mr.Joun Farxy, Sen.; with some preliminary 
Remarks and illustrative Notes by him. 
To Mr. Tilloch. 
Sir, — Taz printed Letter sent herewith, having been put inte 
my hands by a Friend, I am anxious to see the same permanently 
preserved in your Magazine, with a few explanatory Notes, which 
I have taken the liberty of subjoining thereto, partly for the pur- 
pose of explaining, more clearly than was perhaps necessary 
for Dr. R. to do, to his noble Correspondent, or even to most 
of his Irish readers, the situations of the places mentioned, 
partly for referring to former Papers inserted in your Work, on 
this same subject, for asking some questions, &c. 
Dr. Richardson, as many of your Readers know, is the author 
of a highly valuable and curious paper on the Basaltic Strata, 
and Hummocks of the Counties of Antrim and Derry, pages 102 
and 194 of your thirty-third volume ; of another equally valuable 
paper 
