68 Analyses of Books. [Jan. 



phenomena. Thus good conductors are not phosphorescent, but bad 

 conductors are possessed peculiarly of the property of phosphorescence. 



Heat in delating the ultimate particles of eertain bodies, deprives 

 them of their equilibrium, and produces electricity ; but in some cir- 

 cumstances a change in the state of their aggregation is occasioned by 

 the same agency, which is a* very productive cause of electricity. 



State of the globe at its formation. — This is delicate ground to 

 speculate on. M. Becquerel's explanations do not appear to be suited 

 to the object to which they refer, but on the contrary, are bold and 

 even rash. For the sake, however, of giving some insight into the 

 theories which are now emanating from chemical geology upon such 

 an interesting topic, we shall proceed a little farther with the sub- 

 ject. Geologists in general consider that the sedimentary deposits 

 whose layers are more or less inclined to the horizon, have been dis- 

 placed by subterraneous agency, which has acted after their formation, 

 and given to the different elevation on the globe particular characters. 

 These causes having acted at different epochs, it is obvious that several 

 classes of mountains have been elevated which are distinguished by the 

 direction of their course. Von Buch has shewn that the soil of Ger- 

 many may be divided into four systems, and Elie de Boumont has 

 endeavoured to classify the successive elevation of the European 

 mountain ranges by referring them to twelve epochs. In the Alps 

 the secondary and tertiary beds are inclined, while in the Vosges and 

 England all the formations superior to the coal are nearly horizontal, 

 from which circumstance and others of a similar nature, Beaumont 

 has obtained an argument of no small importance to his theory. The 

 systems which he enumerates are : 1. of Westmoreland and Hunds- 

 ruck. 2. Of Ballon (Vosges) and Boccage (Calvados.) 3. Of the 

 North of England. 4. Of Pays-Bas and S. Wales. 5. Of the 

 Rhine. 6. Of Thuringerwald, Bohmerwald and Morvan. 7* Of 

 Mount Piles, Cote d' or and Erzgebrige. 8. Of Mount Viso. 9. Of 

 the Pyrenees. 10. Of Corsica and Sardinia. 11. Of the E. Alps. 

 12. Of the principal chain of the Alps from Valais to Austria. 



Gneiss and granite are the rocks which have disturbed the newer 

 formations, and protrude through them in the form of peaks If we 

 could determine in what state these important constituents of the 

 globe existed in the internal part of the earth, and with what they 

 were associated, a great step would be gained. Our author how- 

 ever has not waited for any accurate knowledge on this head, but in 

 company with M. Ampere has proceeded to theorize. 



He considers the earth to have been primitively in a gaseous 

 state. By the radiation of the heat into the regions of space the 

 temperature of this mass of elastic matter was gradually diminished, 

 condensing the different bodies according to their refractoriness and 

 density. The metals would be first deposited, and would form an 

 immense bath in the centre, from which an enormous heat would 

 emanate, to retard the condensation of the other vapours. The first 

 nucleus would be formed of unoxidized metals, after which less 

 fusible substances would be deposited, producing new compounds. 

 Potassium and sodium, in consequence of their strong affinities for 

 a number of bodies, are convenient substances for effecting powerful 



