298 On the Artificial Formation of Minerals. 
explanation of the processes in their details. Crystallization 
in the ordinary way does not appear very probable ; for, with- 
out reference to the assumption of indefinite periods, savour- 
ing too much of a past phase of geological speculation, the 
very minute solubility of the substances would, judging from 
analogy, seem to justify the opinion, that in gradually sepa- 
rating from solution in consequence of evaporation of water, 
they would be distributed over a considerable surface, rather 
than at particular points, as crystals are found in druses and 
upon lodes. 
The quantity of water evaporated in the formation of 
minerals by crystallization in this way would be enormous, 
in the case of quartz amounting to 25,000 times its volume at 
least. Moreover, when it is considered that this evapora- 
tion must be assumed to take place in the midst of immense 
masses of rock, perhaps saturated with water, the view which 
ascribes the formation of minerals to crystallization from 
solutions in the ordinary way certainly assumes a very ques- 
tionable aspect. 
The occurrence of minerals presents a great number of 
facts which unmistakably indicate a segregative action, in 
consequence of which particular compounds occur in masses, 
or as crystals imbedded in a matrix of a different kind ; 
and although the intimate nature of this process is not un- 
derstood, it is highly probable that the production of mine- 
rals by the agency of water was effected under some such 
conditions, by which the molecules in passing from the liquid 
to the solid state were brought within the range of their 
' ageregative forces in a manner more favourable to the for- 
mation of crystals than deposition from so enormous a a 
portion of water by mere evaporation. 
From a conviction of the need of experimental evidence in 
favour of the aqueous origin of minerals, as well as of a more 
minute investigation of their mode of production, and guided 
by views similar to those expressed above, Drevermann * 
has instituted some experiments with this object, which, 
though not very extended, are sufficiently interesting to — 
merit further prosecution. 
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* Liebig’s Annalen, January 1854, 
