EXPERIMENTS OF MITSCHERLICH. 151 



pelling the carbonic acid, have transformed it 

 into gypsum or sulphate of lime. Sublimations 

 of metals and other elements are also found in 

 fissures in the crust of the earth, driven upwards 

 by forces acting from below. Veins of various 

 minerals appear to have been thus produced. 

 We see the powers of chemistry thus acting 

 far below the surface, and we learn again how 

 small is our every-day perception of the mighty 

 works which are going on beneath us. It is 

 highly satisfactory to be able to add that the 

 connexion of chemistry with all these pro- 

 cesses taking place in the earth's crust, and pro- 

 ducing changes upon the masses of rock there 

 existing, have been practically exhibited in the 

 laboratory by Mitscherlich. By a careful series 

 of chemical investigations, some of the most 

 important simple minerals felspar, mica, 

 blende, &c., garnets, and rubies have been 

 artificially produced, thus completely establish- 

 ing the correctness of the principles upon 

 which geologists are accustomed to explain the 

 phenomena of which we have spoken. 



To the student of nature's chemistries few 

 countries present an aspect so attractive as 

 does the waste and desolate country of Iceland. 

 There may be seen in operation those mighty 

 forces which in more peaceful soils are kept 

 in bondage below the surface. Professor Bun- 



