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nature of Crystallography, or to some other part of 
mineralogical science. 
These are the usual eighteen-sided crystals, interrupted 
in a peculiar manner. 
The right hand figure is in plates a little oblique to the 
base of the pyramid, or to the transverse section of the 
column. The middle figure shows them still more oblique ; 
and the left hand one shows the lamine disposed length- 
wise to the column, with an interruption of another set of 
laminz towards the top. Zhe upper figure has many 
other varieties. 
Most of the specimens which Ihave received of this 
curious subject are by favour of that warm friend to the 
science of Mineralogy, Philip Rashleigh, Esq. 
