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PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 465 
The mineral was got in the southern—the Beg glen of Glen Elg—on its 
south side, about three miles from its embrochure, a little above where the 
limestone disappears, and at a point where a small stream crosses a pathway 
in passing out of a wood to join the river. 
It occurred in somewhat large masses of interpenetrating crystals, of an 
inch or more in size; with eminent cleavages, a somewhat fibrous structure, 
and a lively green colour. Specific gravity, 3-242. 
1°505 grammes yielded— 
Silica, : : , me ag) 
Alumina, . ! ; : Sila 
Ferrous Oxide, . : Nes 123 
Manganous Oxide, . , *398 
Lime, : ; , a OB Ts 
Magnesia, . : : Be for oy 
Potash, . : : : * 504 
Soda, , 3 : : "449 
Water, . ; : : "956 
99 - 962 
4°289 per cent. of the silica insoluble. Possible impurity, a trace of 
actynolite. The small quantity of alumina entitles us to consider this merely a 
dark sahlite. 
A mineral very similar in structure—a readily cleavable augite with pene- 
trating crystals of actynolite—was found by the writer in micaceous gneiss at 
the col—3200 feet high—between Aonach Beg and Ben Aiblen in Inverness- 
shire ; also, near serpentine, at Greenloan, on the Blackwater ; and specimens, 
dentical in appearance with the last, were sent to him by the Rev. Mr Pryton 
of Portsoy, from a crook of the Deveron, a mile west of Kinnairdy Castle. 

Augite. 
From Diorite. (?) 
13. This variety presents an appearance so unusual to augite, that, after 
considerable doubt, I inclined to believe it to be either diaclasite, cr one of the 
non-fibrous and non-bronzy varieties of enstatite. I cannot say that I was 
able to satisfy myself that the masses of rock from which I obtained it were in 
situ. They lay, in somewhat linear disposition, after the manner of a loosened 
or disjointed outcrop. Their site was the west side of the height called 
Craig Buiroch, in Banffshire. They stretched southward along the elevated 
ridge in the direction of Retannach. The ordinary rock of the hill was a some- 
VOL. XXVIII. PART II. 6 E 
