344 M. de Sanarmont’s Experiments upon the 
Experiments upon the formation of Minerals in the Huinid 
way in Metalliferous Repositories. By M. de SANAR- 
MONT. 
Geology has means of investigation which are peculiar to 
itself, and now comprehend a certain number of special truths 
definitely acquired to science. It is thus that geology has 
been able, without foreign aid, to characterize the manner of 
the formation of the sedimentary rocks, and to arrange them 
in series ; it is thus that it has succeeded in distinguishing ~ 
in crystalline rocks, and in metalliferous repositories, different 
classes, of which it can assign the probable origin ; and in 
so far as it has not drawn conclusions too far removed from 
its fundamental principles, its anticipations have been almost 
always confirmed by experiment. It is to mineralogical che- 
mistry that geology owes the useful experimental control of 
its rational conceptions. Crystalline minerals have, in fact, 
a complete chemical origin; and a more thorough study and 
knowledge of them must be advanced by chemical experi- 
ment. Chemistry, then, can do much for geology, by lending 
its means for experiment; but upon the condition of itself 
remaining purely geological, and of borrowing in its turn 
particular means of study, and the general data which the 
science, a priori, has collected upon all the conditional pecu- 
liarities of structure, relative position, association, or mutual 
exclusion, to which certain mineral species must needs be sub- 
ject. In a word, it is necessary that all the circumstances 
where the natural position has left characteristic traces, dis- 
covered by the geologist, should reappear in the artificial 
operation of the chemist. 
The experiments, then, of mineralogical synthesis should 
embrace the different groups of mineral species which are 
united in nature, and should support themselves upon certain 
probable geological inductions concerning the formation of 
the beds which they inclose. Certain isolated species have 
already been obtained, and principally those which approxi- 
mate to the usual products according to the dry method. I 
have attempted to do more, and to discover some indices of 
