of these contain mammalian remains belonging to extinct species, 

 while "the bones of species apparently identical with those 

 now living are never found except in the very latest alluvia ;" 

 these deposits he describes as resulting from causes now in 

 operation, but believes this present state of affairs to have been 

 preceded by a great catastrophe or deluge. 



Referring to this supposition in a paper read before the 

 Geological Society in the year 1819, Dr Buckland says — "For 

 the purpose of impressing more strongly this distinction which 

 I have drawn between dilvvian and post-diluvian gravels, it will 

 be convenient if Geologists will consent to restrict the term 

 diluvium to the superficial gravel-beds produced by the last 

 universal deluge; and designate by the term alluvium those 

 local accumulations that have been formed since that period," 

 by the action of torrents and other causes in daily operation. 



In 1823 Dr Buckland published his BeliquicB Biluviance, 

 and developing more fully his hypothesis that the diluvial 

 deposits were produced by the waters of the Mosaic Deluge, 

 he gave a fresh importance and signification to the terms 

 Diluvium and Alluvium. 



The nomenclature thus proposed by Prof. Buckland was for 

 many years accepted and made use of by Geologists, and it 

 required a long series of close and accurate observations com- 

 pletely to dispel the false ideas and analogies with which this 

 terminology had invested the subject. The principle of the 

 classification however was a sound one, and the original dis- 

 tinction between those formations which originated "in a 

 former and different order of things," and those which have 

 resulted from causes still in operation, has in fact become 

 more clear and defined in the progress of Geological knowledge. 



Thus we find Prof Sedgwick contributing two papers " On 

 the Origin of Alluvial and Diluvial Formations" to the Annals 

 of FJdlosophy for 1835, in which he points out that the 

 Diluvial deposits occur with different characters and generally 

 at different elevations from the Alluvial, but that where both 

 are present the latter always rest on the former, and that 

 they belong therefore to distinct epochs. 



The Diluvial formations he divides into two classes : — " The 

 first composed of coarse materials often lodged at consideral)le 



