588 SUPPLEMENT. 



as leading to the remark, that although certain 

 masses, peaks, rocks, &c. which we see bare, 

 always present a very hard substance, seeming to 

 defy all decomposition ; it is nevertheless subject 

 to the destructive power of time, or more strictly 

 speaking, of the elements ; but in proportion as 

 the particles of that surface are thus decomposed, 

 they are washed away, so that we have always 

 under our eyes the solid part, not yet affected by 

 decomposition. 



" The second example which I shall state, ap- 

 pears at the Seiffenwerk of Steinbach, near Johan- 

 georgenstadt in Saxony. When I was there, and 

 in front of a mountain of granite, of which the 

 surface was entirely decomposed, at the first 

 glance I thought it was a mass of sand or gravel ; 

 but, on approaching, I perceived that the grains of 

 quartz had the same colour and the same form as 

 in the granite of the neighbourhood, and were dis- 

 posed in the same manner, but in a felspar com- 

 pletely decomposed. This decomposition pene- 

 trated a great way into the rock, as I observed in 

 passing into a gallery, where the granite did not 

 appear firm till at the depth of several fathoms : 

 and I am persuaded that in many places what is 

 regarded as gravel, produced by alluvion and 

 transference, is only decomposed granite in its 



