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OBSERVATIONS on CALP. 

 By the Honourable GEORGE KNOX, M.R.I.J. 



xVS the Academy has evinced a defire to promote mineralogical Read, March 

 enquiries in the county of Dubhn ; I take the liberty of fubmit- 

 ting to it the analyfis of a mineral which abounds in the neigh- 

 bourhood of the metropolis, and which our celebrated Prefident 

 has diftinguiflied by the name of Calp. (vid. Kirwan's Elements of 

 Mineralogy, vol. I, p. 233.) 



Calp, or black quarry ftone of Dublin, is placed, in Mr. Kir- 

 wan's Elements of Mineralogy, under the argillaceous genus j being 

 a fubflance which poffeffes the diflinflive charaders of that earth 

 mote than any other. For, although it effervefces with acids and 

 fcratches glafs, it neither burns to lime nor gives fire with fleel. 

 Whilft on the other hand it emits, when breathed upon, the fmell 

 peculiar to argillaceous earth. 



The quantity of argill, however, which its chemical analyfis 



difcovers, would fcarcely,, were its internal properties to d( termine 



its clafs, entitle it to rank in that which Mr. Kirwan has afijgned 



to it- 



Co 3 , The • 



