MR MILNE ON THE MID-LOTHIAN AND EAST-LOTHIAN COAL-FIELDS. 307 



One important inference is fairly deducible from the foregoing views, if they 

 be correct. Wherever the slips are found sloping towards each other in their un- 

 der parts, there must have been a sinking of the strata or district between them. 

 Let us apply this rule to the slips of the Fife and Lothian coal-fields. It has 

 been mentioned that all the slips in Fife slope to the south, — whilst most of the 

 slips in Mid-Lothian slope to the north. This would tend to shew, that there 

 has been a prodigious sinking of the surface between these two shores ; — and pro- 

 bably this may explain in part the formation of that immense hollow, running in 

 an east and west direction, which is filled by the waters of the Frith of Forth. 



It is now time to bring this first branch of my memoir to a close. Let me 

 only add in conclusion, that I think I have at least proved the truth of the obser- 

 vation made at the outset, that, interesting as this part of the island is, on ac- 

 count of its unstratified rocks, — it is no less interesting on account of the pheno- 

 mena which characterize its sedimentary deposits ; — and I trust, that the present 

 attempt to investigate these phenomena, if not attended by any direct benefit to 

 science, will have, at all events, the effect of stimulating other geologists of greater 

 experience and more leisure, to confirm or correct the descriptions I have given, 

 and the opinions I have ventured to express. 



II. On the Superficial Deposits of the Dist7^ict. 



By " superficial deposits," I mean the extensive beds or layers of gravel, sand, 

 clay, and other substances which cover the rocks stratified and unstratified, of 

 the district, — and which intervene between these rocks and the existing vegetable 



soil. 



It is hardly necessary to aUude to the great importance of this branch of the 

 subject. It is important with reference to the particular deposits which are the 

 immediate subject of inquiry ; and not merely in a scientific, but even in a practi- 

 cal point of view. It is important also, on account of the light which it may re- 

 flect, on the origin and formation of older deposits. If, as many geologists sup- 

 pose, aU sedimentary strata, of whatever epoch and character, have been formed 

 by agents similar to those now in operation, the best method of discovering what 

 these agents were, is by studying the phenomena most recently produced by 

 them, and which therefore are the most legible indices of these agents. 



This, however, is a branch of the subject, much more difficult than might 

 have been anticipated. 



No attempt has hitherto been made, that I am aware of, to describe or even 

 to examine the superficial deposits of this district, — or indeed of any of the ad- 

 joining parts of Scotland. There are two short papers in the Transactions of the 

 Wernerian Society, one of which states the different clays found at Blair-Drum- 

 mond, and in the neighbom-hood of Stirling ; the other of which mentions the 



