56 A Geologist h attached to the Trig. Survey. 



apologize for, and correct the too hastv doubts which I have 

 thrown, in pages 427 and -431 of yoiir xlviiith volume, on the al- 

 ledged fact, of Dr. MacCulloch (whose ckemicat services in the 

 Board's Establishments are well known and appreciated) being 

 associated with Col. Mudge and Capt. Coll)v in the Trig. Sur- 

 vey, for applying the principles of Geological investigation, to 

 the ascertaining of the subficial structure of the vicinity of each 

 Station therein. 



Some of the gentlemen who honour me by their friendship, 

 whom I had supposed very likely to know of any such associa- 

 tion, or investigation being on foot, as I have mentioned, were, 

 as I had the means of ascertaining (even since your last number 

 appeared), unacquainted therewith, and that most others of my 

 acquaintance were equally so, I had rea«)ns to conclude : and 

 besides, the notification I have tlirown doubt upon, assumed, that 

 Dr. M. would be"goin2; from station to station will" the Trig. 

 Surveyors, contrary to the fact. These circumstances misled 

 me from the course I ought to have followed, of making direct 

 inquiries, before so expressing myself in print. 



I have sincere pleasure in adding, that I now understand, 

 Dr. MacCulloch entered near three vears ago on the task, taking 

 the Country before him in such order, locally, as he judged best 

 adapted to his investigations, of ascertaining the Geological facts 

 regarding the vicinity of each Station. The great abilities dis- 

 played by Dr. M. in the many valuable I'apers with which he 

 has enriched the volumes of the Geological Transactions, and 

 his known preference, to depending on his own personal observa- 

 tion, as to identity or order of superposition of the terrestrial 

 Masses, to dependence on any Gcognostic Rules, founded merely 

 on the Mineral characters of /land specimens collected (however 

 numerous they mav be), which seems so common among those, 

 who would degrade Geolosy into a mere "branch of Mineralogy ;" 

 all those considerations excite in me great expectations, and a 

 strong desire to see the results of Dr. M's labours towards tlie im- 

 portant objects, on which I liave been solicitous for 15 vears past, 

 as explained in your last number. If you can oblige me by in- 

 sertion at this very late period of the month I shall feel highly 

 obliged, and am, sir. 



Your obedient servant, 

 Ilowland-street, Jan. 26, 1817. JoHN FareY Sen. 



XII. On 



