rm certain Stony and Metalline Suhjlances. 137 



on the 3d of July 1753. How far theft four fubftances have 

 refemblance to each other, it will foon appear not to be my 

 province to anticipate. 



The prefident having done me the honour to fubmit his 

 fpecimens of the Yorkshire and Italian (lones to my exami- 

 nation, I became indebted to Mr. Greville and Mr. Williams 

 for a fimilar diftin&ion : and, being thus pollened of four 

 fubftanees, to all of which the fame origin had been attri- 

 buted, the neeetfky of defcribing them mineralogically did 

 not fail to prefent itfelf. To execute this ta(k, no one could 

 be more eager, and certainly no one better qualified, than 

 the count de Bournon. He has very obligingly favoured me 

 with the following defcriptions. 



Mineralogical Defcriptio?i of the various Stones faid to have 

 fallen upon the Earth. By the Count de Bournon, F.R.S. 



The Hones I am about to defcribe are not of any regular 

 fhape; and thofe which were found in an entire ftate, that 

 is*, thofe which had not been broken, either by their fall or 

 otherwife, were entirely covered with a black cruft, the thick- 

 nefs of which was very inconfiderable. 



The ft ones which fell at Benares are thofe of which the 

 mineralogical characters are the moft ftriking: I (hall there- 

 fore begin the following description with them; and (hall 

 afterwards make ufe of them, as objects of comparifon, in 

 defcribing the others. 



Stones from Benares, 



Thefe flones, as well as the others defcribed in this paper, 

 whatever may be their fize, are covered over the whole ex- 

 tent of their furface with a thin cruft of a deep black colour : 

 they have not the fmalleft glofs ; and their furface is fprinkled 

 over with fmall afperities, which caufe it to feel, in fome 

 meafure, like fhagreen, or fifh-fkin. 



When thefe (tones are broken, fo as to (how their internal 

 appearance, they are found to be of a grayifh a(h colour; 

 and of a granulated texture, very fimilar to that of a coarfe 

 grit- (tone: they appear evidently to be . compofed of four 

 different fubftances, which may be eafily diftinguifhed by 

 making ufe of a lens. 



One of thefe fubftances, which is in great abundance, ap- 

 pears in the form of fmall bodies, fome of which are per- 

 fectly globular, others rather elongated or elliptical. They 

 are of various fizes, from that of a fmall pin's head to that of 

 a pea, or nearly lb; fome of them however, but very few, 

 are of a larger fize» The colour of thefe fmall globules is 



K 4 gray, 



