OF MOULIN-QUIGNON. ' 619 



it was liable to so many sources of fallacy and errors of 

 judgment on the observation, that it must be received with 

 great caution ; and that if the French members of the Con- 

 ference refused to entertain as evidence the intrinsic cha- 

 racters on which he relied so much, and rested entirely upon 

 the circumstantial, he shoidd not feel warranted in advancing 

 further into the inquiry, and must withdraw from the Con- 

 ference. In the end, however, the gisement determined the 

 conclusions arrived at. 



The Conference, augmented by a considerable number of 

 French savants, proceeded to Abbeville on May 12, and 

 commenced operations on the gravel-pit of Moulin-Quignon. 

 The face of the section had been worked back about 10 or 12 

 feet from the spot where the jaw was asserted to have been 

 found, and the debris was piled up in mass upon the spot. 

 The ' black seam ' proper, consisting of a thin layer of man- 

 gano-ferruginous oxides, proved to have been a very local 

 deposit or pocket, which had been worked out. The face of 

 the gravel section showed abundant signs, either of disturb- 

 ance or of derangement, natural or artificial, and if the latter, 

 not of a very recent date. Three chasms, interpreted to be 

 'puisards' or 'sand-pipes,' separated by no great interval, were 

 seen descending from the surface to the chalk ; near the 

 middle of the section masses of sand presented the appearance 

 of having been let down into the gravel, and the ferruginous 

 gravel at the south end of the section exhibited no distin- 

 guishable marks of stratification. The section of one of the 

 so-called ' puisards ' pointed in a direction which, if con- 

 tinued outwards, would not have been more distant than a 

 few feet from the spot where the jaw was asserted to have 

 been found. M. Hebert, the eminent professor of geology to 

 the Sorbonne, after examining the gravel-pit, insisted very 

 strongly to the French geologists around him that the 

 Moulin-Quignon deposit, if not remanie, did not belong at all 

 to the series of Diluvium, or 'Ancient Quatemaiw ' sands and 

 gravels of the Valley of the Somme, such as those of Menche- 

 court and St. Acheul ; but that it was a formation of a 

 much later date. Thin seams of ' gray sand ' were observed 

 a few feet above the chalk, in that part of the section which 

 corresponded with the direction of the spot where the jaw 

 was found. It was held by some of the members of the Con- 

 ference that the sand might account for the ' lining ' of the 

 dental canal; that the jaw might have been first in this 

 alluvial sand before it got into the 'black-seam.' There was 

 no means at the time of comparing the two sands under the 

 microscojje, and taking all the circumstances of the case into 

 account, the conjecture did not appear to me to furnish a 



