ON A PIECE OF CHALK 67 



tend to show, that nothing like an inch of chalk has accumu- 

 lated during the life of a Crania; and, on any probable esti- 

 mate of the length of that life, the chalk period must have 

 had a much longer duration than that thus roughly assigned 

 to it. 5 



Thus, not only is it certain that the chalk is the mud of 

 an ancient sea-bottom; but it is no less certain, that the 

 chalk sea existed during an extremely long period, though 

 we may not be prepared to give a precise estimate of the 

 length of that period in years. The relative duration is clear, 10 

 though the absolute diu^icrP^ffiSJtrj^t be definable. The 

 attempt to affix anj^WecfeS ^atMtro/lfhepteriod at which the 

 chalk sea begai^Q^naed, its existence, m baffled by diffi- 

 culties of theywarfite kind. But the Telatr$ age of the cre- 

 taceous epoclf ma^be determined witt^as great ease and 15 

 certainty as tlffifong duratiorx.pi^ t$kt^ 



You will hav^keard'-of tfeejjitersting discoveries recently 

 made, in various parts of Western Europe, of flint imple- 

 ments, obviously worked into shape by human hands, under 

 circumstances which show conclusively that man is a very 20 

 ancient denizen of these regions. 



It has been proved that the old populations of Europe, 

 whose existence has been revealed to us in this way, consisted 

 of savages, such as the Esquimaux are now ; that, in the 

 country which is now France, they hunted the reindeer, and 25 

 were familiar with the ways of the mammoth and the bison. 

 The physical geography of France was in those days different 

 from what it is now the river Somme, for instance, having 

 cut its bed a hundred feet deeper between that time and this ; 

 and, it is probable, that the climate was more like that of 30 

 Canada or Siberia, than that of Western Europe. 



The existence of these people is forgotten even in the tradi- 

 tions of the oldest historical nations. The name -and fame 



