Mr. Webster on the Strata lying over the Chalk. 19L 



forming to the west of the river a hill, the greatest part of which is 

 now destroyed by the action of the sea. At this place the chalk is 

 about 50 feet in height, and is covered immediately by a bed of sand 

 20 feet thick. Over this are thin strata of yellow marl and clay, 

 containing a coal much resembling that of Corfe and Alum bay. 

 H. Warburton, Esq. Secretary to the Geological Society, who first 

 noticed and pointed out to me these interesting strata, found im- 

 pressions of leaves in the marl which exactly resemble those engraved 

 in one of the plates of the Essay on the Mineralogy of the Environs 

 of Paris : and I have since recognised among the specimens brought 

 from that place, a fruit of one of the palm tribe, with the vegetable 

 fibres quite distinct. Shells belonging to the Genera Cerithium, Gy- 

 therea andOstrea, together with pyritous casts of the same, also occur. 



With this coal are found thin masses of gypsum both selenitous 

 and fibrous ; and over all is a thick bed of blue clay with marine 

 fossils, which are different from those usually found in the London 

 clay. 



It was here that I found the singular substance which the experi- 

 ments of Dr. Wollaston ascertained to be a new mineral, a subsul- 

 phat of alumine. It lies immediately upon the chalk, and fills up a 

 hollow in it. About a mile on the east side of Newhaven the chalk 

 cliffs rise again to an equal height and continue to Cuxhaven, where 

 there is a similar interruption, and thence extend to Beachy Head, 

 increasing regularly in altitude, and forming tremendous precipices 

 of several hundred feet in height.* The chalk here is covered 

 only by a thin layer of sand and gravel. 



* One of these prodigious falls of the chalk cliffs, which make a residence near them 

 frequently so dangerous, occurred a few days before my visiting this spot, accompanied 

 by a remarkable circumstance. The clergyman of East Dean, who was walking near 

 the brink of the precipice, perceived the ground to give way under him, and had the 



