506 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. * 
It yielded— 
Silica, . ,. “"87 } 
From Alumina, . *003 
“74 = 56 * 923 
Alumina, . ; ‘ : 22 
Ferrous Oxide, . ; . 4°647 
Manganous Oxide, . ‘ 076 
cre beetta 8.) thal eer pr as LO 222 
Magnesia, . ‘ ; o Zoo 
Alkalies, . A : . tr. 
Water, . ‘ ; 5 Ie 

99 - 662 
No loss in bath ; was perfectly pure. This is a simple mineral, functioning 
as a rock mass. Both it and the previously described variety might, in the 
state of powder, be used as lubricants, and possibly for polishing purposes. 
Tremolite. " 
6. I am indebted to Dr Joass for sending me from the lime quarries of 
Shinness, in Sutherland, a specimen of this variety; this surpasses in 
beauty anything of the kind I have ever seen from abroad. Nearly a foot in- 
size in all directions, the mass is covered with parallel bundles of glancing 
fibres of the most delicate tenuity ; these flash with a brilliant but chastened 
light, of more than silvery whiteness. 4 
No natural object, devoid of colour, could possibly be more beautiful. 
The specific gravity is 2° 964. 
1°3 grammes yielded— 
Silica, ; , “720 
From Alumina, . *005 
780 = BO oe 
Alumina, . : : : *857 
Ferric Oxide, . ; SOMBIE (on 
Ferrous Oxide, . , : Lia i: 
Manganous Oxide, . : * 069 
Lime, : : 3 ph dior od 
Magnesia, . : : . 24°138 
Potash, . : : ; ‘441 
Soda, : : : ‘ Zila. 
Water, . ? : Aine 2a 
——$<$_— ———__ rt 
100 - 012 

