FORMATION OF NATURAL SOILS. 15 



described by its amiable and well-known historian White. In tho county of 

 Kent, hundreds of similar scenes maintain its character for beautiful scenery 

 and richly pi'oductive soil. Nearer to the great metropolis, if the reader will 

 accompany us a few miles down the North-Western Railway, a rapid ride and 

 a rural walk will place us in the centre of one of these formations. The scene 

 is Harrow — Harrow on the Hill — the cherished Alma mater of poets and 

 statesmen, itself an isolated tertiary formation. Leaving the railway at this 

 station and crossing it by the Pinner Drive, the road leads through a rural 

 farmyard. Beyond the farmyard the path crosses stiles and upland fields, 

 each of which exhibits, more plainly than the last, the shelving bottom of a 

 retiring sea terminating abruptly in a jutting headland beyond which the 

 path descends abruptly to the village of Pinner. How were these prodigious 

 heaps of chalk and other earthy hillocks formed, which give character to our 

 coast and support the soil of so large a portion of its surface ? We have still 

 before us the bed of an ancient sea ; imagine the lowest depths of the Atlantic 

 Ocean — the Atlantidae of Plato, which Lyell is ready to believe in — raised to 

 the level of its surface, and its shallower parts would be a series of hill and 

 dale not unlike the scenes we have been describing. The chalk is partly of 

 animal origin ; each molecule of these immense masses has formerly circulated 

 in the veins of organized beings, or formed some plant which grew and multi- 

 plied in the depths of these cretaceous seas. They were microscopic shells so 

 minute that Ehrenberg calculates that a cubic inch contained 10,000 indi- 

 viduals. Besides this animal deposit, the chalk hills of Kent contain innu- 

 merable flints deposited in parallel beds, often associated with flattened silica, 

 which is extensively employed in the manufacture of porcelain. 



33. The tertiary formation, which forms another great chapter in the his- 

 tory of creation, is the flesh which covers the bony skeleton, and belongs 

 more properly to our subject ; namely, the formation of soils. The lower 

 strata compressed by pressure into solid rock ; the upper portions, the loose 

 soil thrown on the surface, consist of loosely-arranged beds of marine and 

 fresh- water origin ; having none of the grand characteristics which distinguish 

 all the pre\'ious formations ; but, in their place, we have the softened horizon, 

 the rich plains, and smiling hills of a more civilizing landscape. To the 

 earher geologists the tertiary formation was a mere chaos of superficial 

 deposits, which seemed to have no connection with any distinct epoch ; but 

 the researches of Sir Charles Lyell and the recent geologists have caused light 

 to shine on this darkness. Before them, to borrow Addison's beautiful 

 allegory, geology was a bridge, spanning the waters of eternity, of which a 

 thick cloud covered the first and last arch. In our day, the cloud is torn 

 asunder, and the great secret of ancient nature revealed, by the study of 

 shells — medals struck as records of the temperature of the globe. Sir Charles 

 Lyell has deciphered this last chapter of an obscure history, di\ading it into, 

 —1. Lower Tertiaries, or Eocene ; 2. the Middle Tertiaries, or Miocene ; and, 

 3. Piecent Tertiaries, or Pliocene ; each distinguished by its fossiliferous 

 deposits. 



