EVIDENCE DERIVABLE FROM THE FLINTS THEMSELVES. 351 



ordinary flint gravel, would, I am sure, convince any man 

 that these stones, rude though they be, were undeniably 

 fashioned by the hand of man. 



Still it might be supposed that they were forgeries made 

 by ingenious workmen to entrap unwary geologists. They 

 have, however, been actually found by Messrs. Boucher de 

 Perthes, Henslow, Christy, Flower, Wyatt, Evans, myself, and 

 others, under circumstances which preclude all idea of decep- 

 tion. One seen, though not found by himself in situ, is thus 

 described by Mr. Prestwich : " It was lying flat in the gravel 

 at a depth of seventeen feet from the original surface, and six 

 and a half feet from the chalk. One side slightly projected. 

 The gravel around was undisturbed, and presented its usual 

 perpendicular face. I carefully examined the specimen, and 

 saw no reason to doubt that it was in its natural position, for 

 the gravel is generally so loose, that a blow with a pick dis- 

 turbs and brings it down for some way round ; and the matrix 

 is too little adhesive to admit of its being built up again as 



before with the same materials I found also afterwards, 



on taking out the flint, that it was the thinnest side which 

 projected, the other side being less finished and much thicker."* 

 But evidence of this nature, though interesting, is unnecessary; 

 the flints speak for themselves. Many of them are more or 

 less rolled or worn at the edges. Those which have lain in 

 siliceous or chalky sands are more or less polished, and have 

 a beautiful glossiness of surface, very unlike that of a newly- 

 broken flint. In ochreous sand, "especially if argillaceous, 

 they are stained yellow, whilst in ferruginous sands and clays 

 they assume a brown colour," and in some beds they become 

 white and porcellaneous. In many cases, moreover, they have 

 incrustations of carbonate of lime and small dentritic mark- 

 ings. The freshly-broken chalk flints, on the contrtry, are of 

 a dull black or leaden colour ; they vary a little in darkness 



* Phil. Trans. 1860, p. 292. 



