Natural History of Volcanos and Earthquakes. 281 



country, which is principally composed of masses of igneous 

 origin. We shall pass over the consideration of the question, 

 whether this original elevation took place in a fluid or solid state, 

 that is, whether in earlier times these masses rose suddenly and 

 continued to rise more and more slowly as they gradually cooled, 

 or whether this gradually decreasing ratio has always existed. 

 We may, however, be allowed the remark, that the slow eleva- 

 tion which still continues when the operation of the vapor, as an 

 elevating power, has long ceased, may be regarded, according to 

 what has been stated above, as the result of an expansion pro- 

 duced by the caloric disengaged from the vapor during its con- 

 densation. For example, let us assume that the solid crust of 

 the earth in Scandivavia was 139,840 feet thick, that the ex- 

 pansion of this crust by heat takes place in the same ratio as in 

 earthern ware ; then, an average increase of heat of 2°.9 R. du- 

 ring the space of 1000 years, would be stifficient to effect an ex- 

 pansion of 4.26 feet in a stratum of the above-mentioned thick- 

 ness. And this is the average ratio of the rising of that country. 



Be the cause of the elevation of Scandinavia what it may, 

 this circumstance is remarkable, that in the southern part of Swe- 

 den, where the country, according to Nilson's statement, sinks, 

 secondary formations, viz. chalk, occur in great abundance, while 

 in the north of Sioeden, as well as in Finland, the gneiss-granite 

 formation predominates. We must not, however, attach too 

 much importance to the connexion which appears to exist be- 

 tween the elevation of the northern part of Sweden and the prev- 

 alence of the latter formation, as Nilson* says, the chalk also lies 

 on gneiss, and less frequently on greywacke. It is neverthless 

 remarkable that the granite island of Bornholm, which is situated 

 opposite to the sinking coast of (Sc/iowew, is still in the act of 

 rising, according to the observations of Forchhammer above allu- 

 ded to. 



As regards the sinking of countries, there is no difficulty in re- 

 garding it as the result of an elevation of neighboring countries. 

 Yet we can imagine many causes, independent of such elevations, 

 which may produce depressions. It does not, however, lie within 

 the scope of these remarks to enumerate these causes. 



• Petrificata Suecana Form. Crctacoae, &c. 1827, p. 81. 

 Vol. XXXVI, No. 2.— April-July, 1839. 36 



