On the Basaltes of Saxony-. 123 



elusion with every thing that can tend to prove that this 

 kind of rock cannot have a volcanic origin. The author's 

 proofs may be reduced to the following three principal 

 classes: 1st, Position; 3d, Connection; 3d, Structure and 

 Composition of the Basal tes. 



If it be considered then in regard to position, we shall 

 observe, with the author, that it is never found but on sum- 

 mits ; that it cover* all the mineral substances of which these 

 mountains are composed, and that it is never covered by 

 them; that always similar to itself, whether it rests on gra- 

 nite, gneiss, micaceous schist or porphyry, or whether it 

 extends over gres, gravel, sand, and argil, it never partici- 

 pates in the nature of the soil which supports ft. These 

 data conduct to very simple results : the basaltes of Saxony 

 has been the product of a special labour altogether distinet 

 from that which produced the subjacent strata. This labour 

 has been posterior to the formation of primitive roeks ; it is 

 even very recent, since transported earth is among the num- 

 ber of the substances by which basaltes is supported. 



But what is the agent to which we are indebted for this 

 new production ? If tire be admitted, it will be necessary 

 to indicate also the focus where the matters were fused ; the 

 mouths by which they were thrown up ; the route they pur- 

 sued to arrive at thesre summits, which command the coun- 

 try to a great distance around. In this hypothesis the whole 

 will be reduced to either the one or the other of the follow- 

 ing suppositions ; — Each basaltic crown must be considered 

 as the production of a local eruption, or all these masses 

 must be the fragments of an immense stream which for- 

 merly covered the whole region. 



According to the first system, every basaltic mountain 

 must have been a volcano; but who does not know that a 

 volcanic mountain is a confused accumulation of blocks, 

 fragments, rapilli, pumice stones and scoriae, intermixed 

 with torrents of lava ? Here nothing of this disorder is seen : 

 rocks solidly deposited, and regularly placed one upon the 

 other, have retained the situation given them by the water 

 which formed them. Before an eruption, prepared in the 

 interior of mountains, could charge their summits with the 

 basaltes added to them, it would be necessary that it should 

 form a passage in the axis of the mountain; that is tp say, 

 in the line of the greatest resistance ; and where are the traces 

 and aperture of this chimney, which, according to the sim- 

 plest laws of mechanics, must be classed among the number 

 of gratuitous suppositions ? For six hundred years these 

 mountains have been pierced, and their interior parts have 



K 4 been 



