PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 93 
‘9 grammes yielded— 
siligay), ' , . 42°56 
Alumina, . ; i pened 5a oi) 
Ferric Oxide, . : Sey ee el 
Ferrous Oxide, . 2 
Manganous Oxide, *122 
Lime, F : : ed SORA, 
Magnesia, : ; . 20° 742 
Potash, °188 
Soda, é : F *456 
Water, . : 5 By) Mears 
99 -'798 
Loses 14°52 of the water at 212°. 
4. From Glen Farg, in Perthshire.—This specimen was given to me by the 
late ANDREW Morray, Esq. of Conland, as from the amygdaloid of that glen, 
where I have seen smaller pieces of it. The specimen was about two inches in 
length, and had been carved into the shape of a tiger. 
It was devoid of 
structure, much fissured, very soft, unctuous to the touch, semitransparent, 
and of an oily sap-green colour. Its specific gravity is 2° 235. 
1°3 grammes yielded— 
Silica, . : ; "472 
From Alumina, . °003 
*475 = 36° 
Alumina, . : tS 
Ferric Oxide, - , OS Le 
Ferrous Oxide, . 5 
Manganous Oxide, : 
Lime, 2 ‘ ‘ lie 
Magnesia, . : : pene: 
Water, . : ; ee 
99° 
538 
*396 
852 
"246 
°153 
°498 
615 
681 
a9 
Loses at 212° 12-961 of the water ; insoluble silica, 2:947 per cent. Was 
quite pure. 
5. In making the curved cutting on the North British Railway, in Fifeshire, 
immediately landward of the Tay Bridge, beds some three or four inches in 
thickness of this substance of an impure description were come upon. 
