and Writings of Baron Leopold von Bach, 217 



under tins belief; at the same time the original proposer of the 

 theory has himself adduced a large series of facts which have 

 given it a very high degree of development. Its original funda- 

 mental principles, which were derived from the more minute in- 

 vestigation of the Canary Islands, are contained in a valuable 

 work entitled " Physical Description of the Canary Islands" 

 (Physikalische Beschreibung der Kanarischen Inselti), Berlin, 

 1825, 4to, with a folio atlas,* in which, together with the geo- 

 gnostically important facts, there are also many important sub- 

 jects in physical geography treated of, such as the geographical 

 distribution of the plants, the temperature of the springs, and 

 the meteorological phenomena of these islands. Regarding 

 some of the more important subjects which serve as the basis 

 of the theory which we have been discussing, there is much 

 information contained in the two following essays, viz. " On 

 the Structure of Basaltic Islands, and on Craters of Elevation" 

 {Ueber die Zusammensetzung der Basaltischen Inseln undueber 

 Erhebimgs-Kratere), published in the Transactions of the Ber- 

 lin Academy for 1818 and 1819, and reprinted in Leonhard's 

 Taschenbuch for 1821, p. 391 ; and " On the Nature of the 

 Volcanic Phenomena in the Canary Islands, and their con- 

 nection with other Volcanos of the surface of the Earth" 

 {Ueber die Natur der Vulkanischen Erscheinungen auf den 

 Kanarischen Itiseln, mid ihre Verbindung mit andern Vulkanen 

 der Erdoberfldche)^ published in Poggendorff 's Annaleny x. 

 1827. 



After Buch's return from the Canary Islands, he visited the 

 Hebrides on the west coast of Scotland, so remarkable for 

 their richness in trap-rocks, and likewise the Giant's Cause- 

 way in Ireland.t 



Formation of Mountain-Chains, — He now resumed his pre- 

 viously commenced investigations in Germany and the Alps. 

 From a constantly advancing knowledge of the chain of the 



* An octavo edition in French, containing new matter regarding vol- 

 canos, and re\'ised by V. Buch, was published in the year 1036. — Edit. 



t Von Buch remained about three months in Scotland. Ho not only vi- 

 sited the Hebrides, but also examined the geognosy of the Forth district dur- 

 ing his residence in Edinbui^h, where we had the happiness of making bis 

 acquaintance. — Edit. 



