2S2 The Rising (^'Scandinavia explained. 



us to form a correct estimate of the quantity of matter ejected ; 

 we must take further into account the combustible substances 

 which have vanished, the gases which have escaped, the dust 

 and ashes which, projected into the air, have fallen many miles 

 distant from the place of explosion *. Then only can we enter- 

 tain a just idea of the cavities that must have been created in 

 the interior of*1:he earth by the escape of a mass of matter com- 

 petent to produce an Etna or a Chimbora^o. Such cavities are 

 ill suited to support such mountains ; La Metherie therefore 

 supposes cavities to be at a distance, and volcanic matter to flow 

 from these through long galleries and fissures of communication. 

 Nor have we in volcanic countries alone decisive evidence of the 

 existence of subterranean cavities. No rock is exempt from As- 

 sures : in thick beds of limestone, fissures and caverns are ex- 

 ceedingly abundant ; and the extent of these last is sometimes 

 prodigious. Who has not heard of the grotto of Antiparos ? of 

 the caverns of Carinthia and Carniola, the content of which 

 amounts to some hundred thousand cubic feet ? of the King- 

 ston Cave recently explored near Michelstown in Ireland .? 



To the frequency of caverns and openings, by whatever name 

 designated, I ascribe many of the inequalities which vary the 

 surface of the earth ; such openings, I conceive, produce pheno- 

 mena sometimes of subsidence, sometimes of elevation. I can- 

 not entertain a doubt that many of the tilts and contortions of 

 strata usually ascribed to soulevejnent have been occasioned sole- 

 ly by want of adequate support. 



The Duchy of Finland exhibits an endless series of lakes fill- 

 ing up the hollows of a granitic surface. Let me be allowed a 

 similar series of subterranean lakes occupying similar basins be- 

 neath the level of the Baltic, and receiving, by means of fissures 

 extending up to the summits of the Scandinavian chain, a con- 

 tinual supply of water which has no outlet ; in other words, let 

 me be allowed the use of hydrostatic pressure ; and without 

 having recourse to central heat or secular refrigeration, I think 

 I shall be able to account, without difficulty, not by a general 

 and uniform rising, but by a num.ber of unequal and partial 



• In 1783, a submarine volcano off the coast of Iceland ejected so much 

 pumice that the ocean was covered to a distance of 150 miles, and ships were 

 considerably impeded in their course. 



