between Archaeology and Geology. 2\'^ 



before, under any circumstance, opened to the inspection of 

 the antiquary." 



The nature of this numismatic conglomerate is seen in 

 a small specimen, which I have fortunately rescued from 

 destruction. It contains two silver coins of Edward I., so 

 exposed as to show part of the effigy and superscription of 

 the obverse. 



The history of this accumulation of money, and conse- 

 quently the age of the conglomerate, is clearly made out. 

 In the reign of Edward II. (a.d. 1322), the forces of the 

 Earl of Lancaster, then in open rebellion, being compelled 

 to retreat from the royal army, crossed the Dove, which at 

 that time was scarcely fordable, and in the haste and panic 

 that prevailed, the military oak-chest, banded with iron, was 

 sunk in the river. On the decay of the wooden chest, the 

 coins it contained became intermingled wdth the gravel and 

 sand ; and the iron bands decomposing supplied the cement 

 by which the loose materials were converted into a ferrugi- 

 nous breccia, as hard and durable as the ancient conglome- 

 rates which contain the teeth and bones of species of animals 

 that have long since been obliterated from the face of the 

 earth. 



In the Thames, beneath the superficial mud and silt, a 

 layer of breccia or conglomerate, in which Roman coins and 

 pottery are imbedded, is spread over many parts of the river 

 channel. This concrete is composed of pebbles, sand, and 

 mud, consolidated by ferruginous infiltration. In this ex- 

 ample, for which I am indebted to the liberality of Mr Roach 

 Smith, there are exposed the half of a denarius of Severus or 

 Caracalla, and a small brass of Tetricus. I have also speci- 

 mens containing coins of the Lower Empire, that were col- 

 lected from the bed of the Thames by Henry Brandreth, Esq., 

 in whose possession I saw gold and silver Roman coins in a 

 mass of conglomerate, dredged up many years since near 

 London Bridge. 



Skulls and other parts of the skeletons of domestic ani- 

 mals, as the dog, cat, sheep, have been found in this modern 

 fluviatile deposit, in the same mineralized state as fossil 

 bones in tertiary strata of a similar character. 



q2 



