84 Professor Hausmann 07i Metallurgical Phenomena. 



size of several inches, and completely transformed by the pe- 

 netration of the silicate of the protoxide of iron ; in which mass 

 too, the individual quartz grains of the sandstone may still be 

 distinguished. The transformed sandstone is partly distinctly 

 separated from the mass of the vein and partly amalgamated 

 with it. These relations display a striking analogy with the 

 phenomena, which accompany granite in several places, where, 

 as takes place in the Harz, it is in contact with the greywacke. 

 The chert which surrounds the granite, and which is often 

 just as intimately associated with it as with the greywacke, 

 appears to have been formed by the penetration of the mass of 

 granite into the adjoining mountain rock. The most perfect 

 amalgamation often takes place, but still the individual ingre- 

 dients also are often visible, and distinct granite is found branch- 

 ing away into the intimately blended mass. In tiie same pro- 

 portion in which the crystalline structure of the granite disap- 

 pears, the conglomerated nature of the greywacke comes more 

 prominently into view. 



This parallel induces us, at the close of this inquiry, to di- 

 rect the attention to still one particular, which has reference to 

 the whole subject. The inconsistency, which a comparison of 

 such diminutive phenomena as those of the processes of the 

 foundry, with the gigantic organization of the earth's crust, 

 might have for many individuals, disappears, as soon as we dis- 

 tinctly perceive, that it is not absolute, but merely relative great- 

 ness, that comes into consideration. A vein of lead-glance, a 

 few lines in breadth, found in the wall of a melting furnace, has 

 proportionally much larger dimensions, than the most stupen- 

 dous veins of ore in our mountains : and if a piece of sandstone, 

 a cubic foot in contents, be traversed by a fused body half an 

 inch in size, which has, by penetration, caused the removal of 

 the contiguous stone to the distance, it may be, of a few lines, 

 or of several inches, the change effected here is of much greater 

 importance than that which is perceived in the influence exerted 

 by the granite of our Harz on the adjoining greywacke. If, 

 then, in a melting furnace such effects could be produced by 

 vapours, or in the filling up of fissures by means of fused masses, 

 how much greater is the probability that similar phenomena 

 might ensue fi'oni the ascent of vapours and fused masses from 



