yo Dr. Beddoes’s Obfervations , See. 
the araygdaloides rocks have been formed by the infiltration of water. The cryflals are 
frequently of fo large a fize that you can by no means fuppofe the quantity of water, 
at any one time exifling in the cavity, could have held the folid matter, of which 
they confiff, in folution. Now, I think, it is contrary to all our experience in che- 
miflry, to fuppofe cryflals built up by fucceffive operations. If upon cryflals of 
nitre I pour a folution of the fame fait, the former cryflals will not be enlarged 
and amended, but a new fet will be formed ; fo fucceflive quantities of water, 
palling through thefe cavities, ought to form fucceffive fets of very fmall cryflals. 
Neither can I imagine, what caufes can produce within thefe cavities a depofition 
of the matter once diffolved by the water. It is not cooled ; it does not evapo- 
rate; it lofes no fixed air ; it comes in contact with no new matter, whofc attrac- 
tion may overpower the attra&ion of the water. 
The divifions, 44 rather marked out thau formed, which crofs each other 
irregularly (p. 533*), and indicate an incipient retra&ion,” are much more con- 
fiflent with a fimuitaneous congelation than a gradual appofition ; and the granite 
is the fame as that of the contiguous hill in the colour and appearance of its 
conflituent parts. This coincidence is a flriking fa<£t. 
In truth, the philofophers who attribute the formation of granite to water feem 
not to have advanced a flep in their proof beyond the^equivocal circumffance of 
its being a cryflallized mafs. 
