in the Neighbourhood of London. 219 



fact most of the higher grounds and heaths present myriads 

 of myriads, and in the other parts of the country they are 

 scattered, but not so plentifully. In the deep vales of the 

 Cray and Darent they are wanting. 



There is one spot beyond the boundaries above described, 

 where such flints are exceedingly abundant, which is the hill 

 immediately above the firestone quarries, a mile north from 

 Godstone Green. 



The best place near London where these flints may be 

 seen to advantage, is at the top of Blackheath hill, immediate- 

 ly in front of the Green Man hotel. One single view of such 

 a collection as is there will give a better idea than any de- 

 scription. 



As to size, many of the Blackheath flints are not larger 

 th&npease axidbeans, and by such designation they are known 

 to builders and plasterers. The greater part are however 

 larger, from a pigeon's egg to a hen's egg, and a small pro- 

 portion of them are even as large as a swan's egg, only rather 

 flattened. The colour on the exterior is sometimes blue, but 

 it is generally of a brownish or rusty appearance. 



The form of Blackheath flints is uniformly a flattened el- 

 lipsoid. The perfect sameness of form is perhaps the most 

 remarkable circumstance about them, and suggests the idea 

 of their having acquired it by means of gentle agitation whilst 

 yet in only a soft state. 



When broken by the hammer the fracture is not like that 

 of chalk flints, being not nearly so much conchoidal. The 

 appearance is most frequently horny or waxy, with frequently 

 white spots, but it is sometimes reddish, though comparative- 

 ly seldom. 



Blackheath flints are seldom at all affected by long expo- 

 sure to the air. Countless multitudes of them may be seen 

 on the surface, and near to it in many places within the country 

 where they are found, and have been so exposed for a period 

 to which we can set no limit : yet they have not acquired 

 a white crust nor even any white film making any approach 

 to it. However on the south side of the Addington hills, the 

 sun has produced an effect, and whitened to a small degree 

 the flints exposed to his rays. 



Blackheath flints may be burnt in the fire, without their 

 exploding, which is seldom the case with other flints. This 

 has been attributed to their containing less water than other 

 flints, and it may possibly be so. 



After being burnt in the fire the fracture is very rough and 

 uneven, and often appears as if blistered. The colour is a 

 dirty white with a considerable mixture of red produced by 



