Occurrence of Flint-implements in Gravel-beds. 231 



The subject has, however, been latterly revived, and the evidence 

 more carefully sifted by Dr. Falconer ; and his preliminary reports 

 on the Brixham Cave*, presented last year to the Royal Society, 

 announcing the carefully determined occurrence of worked flints 

 mixed indiscriminately with the bones of the extinct Cave Bear and 

 the Rhinoceros, attracted great and general attention amongst geo- 

 logists. This remarkable discovery, and a letter written to him by 

 Dr. Falconer on the occasion of his subsequent visit to Abbeville 

 last autumn, instigated the author to turn his attention to other 

 ground, which, from the interest of its later geological phenomena 

 alone, as described by M. Buteux in his " Esquisse Geologique du 

 Departement de la Somme," he had long wished and intended to 

 visit. 



In 1849 M. Boucher de Perthes, President of the " Socicte 

 d'Emulation" of Abbeville, published the first volume of a work 

 entitled " Antiquites Celtiques et Antediluviennes," in which he an- 

 nounced the important discovery of worked flints in beds of undis- 

 turbed sand and gravel containing the remains of extinct mammalia. 

 Although treated from an antiquarian point of view, still the state- 

 ment of the geological facts by this gentleman, with good sections 

 by M. Ravin, is perfectly clear and consistent. Nevertheless, both 

 in France and in England, his conclusions were generally considered 

 erroneous ; nor has he since obtained such verification of the pheno- 

 mena as to cause so unexpected a fact to be accepted by men of 

 science. There have, however, been some few exceptions to the 

 general incredulity. The late Dr. Rigollot, of Amiens, urged by 

 M. Boucher de Perthes, not only satisfied himself of the truth of 

 the fact, but corroborated it, in 1855, by his "Alemoire sur des 

 Instruments en Silex trouves a St. Acheul." Some few geologists 

 suggested further inquiry ; whilst Dr. Falconer, himself convinced 

 by 11. de Perthes' explanations and specimens, warmly engaged 

 Mr. Prestwieh to examine the sections. 



The author, who confesses that he undertook the inquiry full of 

 doubt, went last Easter, first to Amiens, where he found, as de- 

 scribed by Dr. Rigollot, the gravel-beds of St. Acheul capping a 

 low chalk-hill a mile S.E. of the city, about 100 feet above the level 

 of the Somme, and not commanded by any higher ground. The 

 following is the succession of the beds in descending order : — 



Average thickness. 



1. Brown brick-earth {many old tombs and some coins), 

 with an irregular bed of flint-gravel. No organic remains. 10 to 15 ft. 

 Divisional plane between 1 and 2a very uneven and indented. 



la. Whitish marl and sand with small chalk debris. Land 

 and freshwater shells (Lymnea, Succinea, Helix, Bithynia, 

 Planorbis, Pupa, Pisidium, and Ancylus, all of recent 

 species) are common, and mammalian bones and teeth are 

 occasionally found 2 to 8 ft. 



* On the 4th of May, this year, Dr. Falconer further communicated to the Geo- 

 logical Society some similar facts, though singularly varied, recently discovered 

 by him in the Maccagnonc Cave near Palermo. — See Proc. Geol. Soc 



