8 THIRD REPORT — 1838. 



at Freyberg in 1791. Werner adopts, in the first place, the 

 proposition that the spaces now occupied by veins were origi- 

 nally rents formed in the substance of rocks, and states that 

 this is not a new opinion. 



He claims the merit of having ascertained in a more positive 

 manner the causes which have produced these rents, and of 

 having brought forward better proofs of it than had formerly 

 been done. 



He admits that rents may be produced by many different 

 causes, but he assigns the greater part to subsidence. He lays 

 it down, that when the mass of materials of which the rocks 

 were formed by precipitation in the humid way, and which was 

 at first soft and moveable, began to sink and dry, fissures must 

 of necessity have been formed, chiefly in those places where 

 mountain chains and high land existed. He adds, that rents 

 and fissures are still forming from time to time in mountains 

 which have a close resemblance to those spaces now occupied 

 by veins, and that this happens in rainy seasons and from 

 earthquakes. 



He adduces as a proof of his assertions, that veins, in respect 

 of their form, situation and position, bear a strong resemblance 

 to rents and fissures which are formed in rocks and in the 

 earth ; that is to say, both have the same tabular figure, and 

 the deviations which they make from their general direction 

 are few in number and very inconsiderable ; and he remarks, 

 that all the veins of a mining district, more particularly when 

 they are of the same formation, have a similar direction, which 

 shows them to have been produced by the same general cause. 



But what Werner claimed as altogether new, and what he 

 challenges as his own particular discovery is, 



1. To have determined and described in a more particular 

 manner the internal structure of veins, as well as the formation 

 of the different substances of which they are composed, and to 

 have settled the relative age of each. 



2. To have given the most accurate observations and most 

 perfect knowledge of the meetings and intersections of veins, 

 and to have made these observations subservient to the deter- 

 mining their relative ages. 



3. To have determined the different vein formations, parti- 

 cularly metalliferous veins, as well as their age. 



4. To have been the first who entertained the idea that the 

 spaces which veins occupy were filled by precipitations from 

 the solutions, which at the same time formed by other precipi- 

 tations the beds of mountains, and to have furnished proofs of 

 this : and, 



