262 Dr T. THOMSON'S Account of the 



11. Leelite of Dr CLARKE. 



I got a specimen of this mineral, which occurs at Grythittan 

 in Nerike, many years ago from Mr SVEDENSTJERNA. I had 

 arranged it in my cabinet as a specimen of compact felspar. 



Its colour is flesh-red ; its structure compact ; its fracture 

 splintery, and also conchoidal ; its transparency that of horn ; 

 its specific gravity 2.606. Mr R. MITCHELL analysed it at my 

 request, and obtained 



Silica, 81.91 



Alumina, .... 6.55 



Protoxide of Iron, . 6.42 



Potash, 8.88 



be 



103.76 

 Dr CLARKE had analysed it, and he states its constituents to 



Silica, . . . . . 75.0 



Alumina, . . . . 22.0 



Manganese, . . . 2.5 



Water, 0.5 



100 



* 



It is possible that the specimen analysed by Dr CLARKE 

 might have differed from mine ; but no great confidence can be 

 put in Dr CLARKE'S analyses, as he had not much practice, and 

 was not probably able to determine the purity of the substances 



* See Annals of Philosophy, xi. 367. 



