NOME VIII. KOLLANITE. 



pavement. The masons of that time, not ob- 

 serving its beauty and singularity, have often 

 mixed it with common flint, as it occurs in the 

 neighbouring quarries, in the walls of the Abbey 

 Church and its precincts, and in those of the 

 nunnery of Sop well. The author even found at 

 the spot called Gorhambury Block, a piece 

 which had fallen from the Roman walls of 

 Verulam ; being flat, like a Roman brick, with 

 some mortar adherent. But as a beautiful and 

 valuable stone, it seems to have been unknown 

 till the seventeenth century. 



It is also said to have been observed in the bed 

 of the River Lea, at Luton. The ingenious Mr. 

 Parkinson, whose work on petrifactions is well 

 known, observes in a letter to the author, (e that 

 towards Ware, in the south-east, and from 

 Amersham to Kings Langley, on the south-west, 

 I have sought for it in vain ; but between Hemel 

 Hampstead and Tring, I have seen large masses, 

 which I suppose have been dug up in that neigh- 

 bourhood. The flint containing Alcyonia, &c. 

 ceases about Amersham j and soon after, I be- 

 lieve, rather more to the north, commences the 

 pudding-stone." In short, if we take a line from 

 St. Albans in the south, to Market Street in the 

 north j and from Tring in the west, to Hatfield 

 in the east ; we shall have an oblong-square, of 



