EXPERIMENT IN MINERALOGY. 



IT might appear unnecessary to call attention to the value 

 of experiment in any branch of science ; but we have 

 to remember that at no very distant date mineralogy was 

 formally divorced therefrom, and a complete reconciliation 

 has never yet taken place. 



In the first half of the present century, under the supre- 

 macy of the natural history school of Werner, the study of 

 minerals was expressly confined to such features as could be 

 examined by observation alone. In the words of Mohs, who 

 may be regarded as the exponent of this school, "minera- 

 logy is the natural history of minerals"; "natural history 

 considers the natural productions as they are, and not how 

 they have been formed " ; "the natural-historical properties 

 are those with which nature has endowed the bodies which it 

 produces, provided those properties as well as the bodies 

 themselves remain unaltered during their examination ". 



Nothing can be further removed from experimental 

 science than this. In the light of present methods, some of 

 the dicta of Mohs appear to a modern reader absolutely 

 opposed to the spirit of progress. For instance: "It. is 

 very difficult to attain a correct knowledge of the produc- 

 tions of the mineral kingdom, if we confine ourselves to 

 empiricism. Besides it is a waste of time, and the infor- 

 mation thus acquired is at the best uncertain." If a person 

 intends to acquire solid information in mineralogy he is re- 

 commended to "examine well-arranged collections which 

 may be said to be useful only to those who wish to enlarge 

 their information by observation and inquiry ". " Properties 

 which can only be observed during or after a change can- 

 not be employed agreeably to the principles of natural 

 history, and must therefore be excluded from mineralogy. 

 Properties of this kind are : the fusibility of minerals 

 examined before the blow-pipe ; their solubility in acids ; 

 phosphorescence produced by heat ; chemical analysis 

 instituted to ascertain the quality or relative quantity of 

 the component parts " (i). 



