230 Extracts from the third Volume of 



which fell at Ensisheim, November 7j 1 742 5 at Bonrg, *m 

 Bresse, September 1 753 ; at Agcn, July 24, 1 790 ; in York- 

 shire, December 1 795 ; at Sallcs, near Villefranche, in Beau- 

 jolais, March 12, 1798 ; and at Benares, December 179B. 



M. Lesage explains their formation in the atmosphere* ; 

 but even if this should not be explained by the chemists, I 

 shall, till the philosophy of meteorologv is further ad- 

 vanced, consider them as an atmospheric production. 



XL. Extracts frem the third Volume of the Analyses 

 of M. Klaproth. 



[Continued from p. 8!i;] 



Grayish White Phosphated Ore of Lead. 



According to M. Klaproth's analysis, this gray ore of 

 lead, crystallized in thin and very brilliant prisms, is com- 

 posed of 4|. oxide of lead and one part phosphoric acid. He 

 is not acquainted with the matrix of this ore, which he very 

 much regrets, as white phosphated ores of lead are exceed- 

 ingly rare. This species of ore proves how uncertain are 

 the signs borrowed from colours for the classification of 

 minerals. It is proper to remark that the muriatic acid dis- 

 covered in phosphated ores of lead is always found in them 

 in nearly the same proportions. 



Analysis of the Phosphated Lead Ore of Anglesey. 



The sulphated lead ore of the Parisle Mountain of the 

 Island of Anglesey is found in small insulated crystals, the 

 iorm of which appears to be an mclined pyramid of four 

 faces. They are always inclosed in a hard stratum of brown 

 ochre, sometimes uncoloured and without spots ; but often 

 embrowned by a slight tint of ochre : in the inside they 

 Jiave great brilliancy. 



Their specific gravity is 6300 : exposed on charcoal to 

 the blowpipe they decrepitate as soon as the flame touches 

 thern. When reduced to powder they fuse into a brilliant 

 scoria, which is at length converted into a button of mc- 

 t^liic lead. 



* Journal de Physique, MessiJor, an. 11. 



This 



