On the Aerated Barytes. 599 



for curiofity, than for ufe. Inftigated by this 

 motive, and at the defire of my friend Mr. Cooper, 

 I have undertaken to lay before the Society an 

 account of the only mine in England* in which, 

 according to the beft of my information, any 

 Aerated Barytes has been difcovered. At the fame 

 time I fhall fubmit the few obfervations which two 

 fhort vifits have enabled me to make upon the 

 natural hiftory of a foflil, concerning which the 

 curiofity of Mineralogifts has been ejjcited, but 

 never gratified. 



The firft intimation of the Aerated Barytes exift- 

 ing naturally, was given by Dr. Withering, who 

 publifhed an excellent analyfis of it in the Philofo- 

 phical Tranfaftions, for the year 1784, wherein he 

 has left us little to defire refpefting its chemical 

 properties. However he was mifinformed as to the 

 place from whence his fpecimen came, which he 

 fuppofed to be Alfton Moor, where I have good 

 authority for advancing, that none has been found. 

 He has fince informed me that he believes it came 

 from the fame mine of Anglezark, which forms 

 the fubjeft of the prefent paper. 



* In Scotland it has been found in the mines of Strontain 

 and Dunglafs, near Dumbarton, but I have not heard of 

 its being yet difcovered on the Continent. A Foffil fent 

 from Scotland to Dr. Crawford, as the Aerated Barytes, 

 and not very diffimilar in its external appearance, feems 

 from his experiments to contain a perfeftly Neiv Earth. 



Q^q 4 The 



