I'll i;(ii;ii;s ok ohI'; disposition ii istokicallv considered. 319 



he (jiiostioiKMl whether it did not ret;ir(l it, since throiiijli tlie <j,'i-eat 

 weight of the niithor's name it remained a standard work in (lermany 

 Ion*; at'tei- many of his peculiar i>«'oh)i>ieal tlieories liad been dis- 

 carded. Its merit hiy less in the novelty of the views advanced, most 

 of which had already been put forth by one or another of his prede- 

 cessors, than in the logical way in which they were presented. 



The principal points Avith regard to the origin of oi-e deposits 

 which may be considered as fairly Avell established by Werner's 

 teachings are that they are the filling of fissures and cracks of later 

 formation than the inclosing rocks, and consist of foreign material 

 ,subse(iuently introduced, largely in aqueous solution. As to the 

 fissures themselves, while a certain systematic arrangement had been 

 noted in their directions, and the fact that, where by intersection, 

 one had been shifted or faulted by another, inferences as to their 

 relative age might be drawn, little definite conception Avas appar- 

 ently had as to their origin beyond the general suggestion that they 

 might be the result of subsidence or of contraction of the rock masses 

 in which the}^ occur. 



Any important advance over these rather crude conceptions Avas 

 hardly to be looked for until very decided jjrogress had been made in 

 the broad general theories of geology, and tliis progress Avas neces- 

 sarily very sIoav. Although the period of reasoning from facts of 

 nature to generalizations had commenced, the tendency to pure 

 speculation Avas not yet extinct, and resulted in many remarkable 

 theories, such as that put forth by Professor Oken, of Jena, Avho, 

 in his text-book of Natural Philosophy (ISOO'I, assumed that the 

 earth Avas a polyeder formed according to the hnvs of crystallo- 

 graphy, and that A^eins or fissures resulted fi"om the loss of the 

 Avater of crystallization. For the genesis of ores, darkness, earthy 

 Avater, and air are necessary; hence there can be no ore in the interior 

 of the earth, since no air reaches it, etc. Or, again, that of Breislak, 

 the Italian geologist (1811), Avho put forth a j^dutonic earth theory 

 Avhich supposed that Avhile the rocks Avere still in a molten condition 

 the metals had a tendency to separate under the influence of specific 

 gravity and of certain chemical and physical affmities, and localized 

 themseh'es in A'eins Avithout entirely separating from their country 

 rock. This is apparently the first enunciation of the modern theory 

 of magmatic segi-egation. The metallic gi-ains in placers he supposed 

 to have been granulated like slag on coming in contact with water. 



The peculiar vieAvs of Werner naturally held SAva}^ longer in Ger- 

 many than elsewhei-e, yet it Avas his favorite pupils that AA^ere first 

 led. in their widening fields of obserA'ation, to abandon his theory 

 that basalt is of aqueous origin, though altered by the heat produced 

 through the combustion of neighboi'ing beds of coal. 



Von Buch, for a long time the leading geologist of Germany. Avas 



