Yol. 56.] AT WEST WICKHAM (KENT). 9 



have been much bruised and crushed on the more prominent points 

 by local influences, such as the ploughshare and the broad waggon- 

 wheels employed by the farmer. It has been supposed by some 

 that this bruised condition of the implements is due to excessive 

 Drift-action, but I think it much more probable that it has been 

 produced by the implements of husbandry. 



(v) Most of the specimens have a superficial colouring varying 

 from a pale straw colour to a rich ochreous-brown. It is, I believe, 

 generally assumed that this colouring arises from the bed of clay in 

 which the flints have been deposited for so long, but I am not quite 

 convinced that this is the only, or even the chief, cause of the 

 ochreous staining. Flint contains much iron, and one is tempted 

 to enquire whether the staining may not be the result of oxidation 

 of that metal liberated in the process of partial decomposition of 

 the flint. The following seem to be the chief evidences that 

 the Drift -implements have received their ochreous colour from 

 some chemical change in themselves rather than from their 

 environment : — 



1. The ochreous colour is found only upon the surface or slightly 

 below the surface of a flint which has undergone structural altera- 

 tion. 



2. It is not found to the same degree or in the same manner 

 upon the original skin of the flint, portions of which remain upon 

 the implements. The fact that this skin contains more lime and 

 less iron than the flint proper would seem to account for this 

 circumstance. 



The proportion of iron in a Chalk-flint is variable. Klaproth, 

 whose analysis is so frequently quoted, places ' oxide of iron ' at 

 •25, but several chemists have assured me that the proportionate 

 amount of protoxide of iron is often greater than this. Even were 

 it not so, the proportion quoted by Klaproth would be sufficient 

 to account for the deep stains which we find, as iron in a ferric 

 state has very high colouring properties. 



(vi) The association of much-worn implements, unworn imple- 

 ments, and flakes, cores, and waste chips in the same bed of Drift- 

 gravel points to the fact that we have here a collection of material 

 which has been brought from a great variety of places, and has 

 undergone a great variety of conditions and changes. 



Discussion. 



Mr. A. M. Bell said that he was glad to see the Author's collection, 

 as he had for many years gathered together a somewhat similar collec- 

 tion from near Limpsfield on the Greensand escarpment, 10 miles to 

 the south of "West Wickharn. The Author's specimens had a, fades 

 of their own : they did not closely resemble those of Limpsfield, or 

 of Ightham, or of Swanscombe. The speaker had classed the 

 Limpsfield collection as belonging to three different periods : the 

 earliest being of rare occurrence. On seeing the Author's collection, 

 it struck him as strange that the latest period, well represented at 



