OF MOULIN-QUIGNON". 609 



was insinuated into the pores of the whitish-grey incompact 

 parts of the flints, there was some difficulty in removing the 

 specks with the brush. 



The characters of the flint-gravel of the ' black seam,' an 

 important part of the evidence, were submitted to examina- 

 tion. Specimens were handed in on both sides. The great 

 majority of the pebbles, and more especially the larger ones, 

 were deeply stained with iron or covered with dendrites. The 

 Trench members produced some fragments, mostly small 

 and angular, which when washed they considered to be 

 nearly free from tinting. The precise numerical ratio of the 

 latter to the former was not determined at the Conference. 

 The English members held, that the exceptions were so few 

 as not materially to alter the complexion of the evidence. 

 Dr. Carpenter, by a written question which he handed in to 

 be put to Professor Delafosse, implied that while the sus- 

 pected haches were ' free from coloration or dendrites, the 

 ordinary flints of the same bed universally presented such 

 indications.' Mr. Evans states that 'the pebbles in the 

 " black band," in which the haches are said to have been 

 principally found, are without exception more or less stained 

 by the ferruginous matrix, a stain which cannot be removed 

 by washing.' Mr. Prestwich, during his subsequent visit to 

 Abbeville, took the opportunity of making the experiment 

 omitted by the Conference. He washed a portion of the 

 gravel containing 135 flint-fragments, and found that 108 of 

 them were completely stained and coloured, 22 partially so, 

 and only 5 (all small) not at all altered : the last thus forming 

 less than 4 per cent, of the whole. He admits ' that the rarity, 

 therefore, of unaltered flints in this bed is in contradiction to 

 the unaltered condition to the totality of the flint implements 

 of the new type,' i.e. the suspected ones. 



The thin layer of argillaceo-metalliferous matter, constitut- 

 ing the ' couche noire' or 'black seam' proper, was also ex- 

 amined. It lay immediately upon the chalk, portions of which 

 adhered to the under surface of ten specimens exhibited. No 

 detailed chemical analysis of this substance was submitted to 

 the Conference ; but a qualitative analysis was communicated, 

 showing that it consisted of fine earthy matter highly charo-ed 

 with oxides of iron and manganese, and that it contained no 

 organic materials. Professor Williamson, of University 

 College, has since caused a careful analysis of the substance 

 to be made, in the ' Birkbeck Laboratory,' by his able 

 assistant Mr. Haughton Gill. The results, published in one 

 of the explanatory notes appended to the proces-verbaux, 

 establish that more than half of the substance of the ' couche 

 noire ' consists of matter insoluble in hydrochloric acid, and 



VOL II. B r 



