460 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 
Specific gravity, 3° 142. 
1: 486 grammes of the Tiree sahlite yielded— 
Silica, . : ‘ *74 
From Alumina, . “OG 
aicauh == 50 536 
Alumina, ; ; . 4°688 
Ferric Oxide, Y . 4:°144 
Ferrous Oxide, . : : Oog 
Manganous Oxide, . : 686 
Lime, : ‘ : = 23" D9 
Magnesia, ; : . 14°401 
Potash, . : : ‘ *314 
Soda, : j , : * 633 
Water, ; : i a6 
100 : 507 
2-961 per cent. of the silica insoluble. 
The crystals having been dissolved out of the lime by weak acid, must 
have been pure from all contamination, except, perhaps, a minute crystal of 
sphene, of which there is no evidence.* 
8. From Eslie, near Banchory, Kincardineshire. 
The bed of lime which courses down the south side of the Dee, and which is 
thrown in wrinkles to the surface every four or five miles, between Inver Inn 
and Banchory, nowhere carries augitic minerals, except in ill-developed specks, 
until it shows itself in the hill above Eslie, three miles south of Banchory. 
In the quarry on the south of the top of the hill, crystals of sahlite an inch 
or two in size were found by Nicot. These are associated with pyrrhotite, 
sphene, talc, rarely oligoclase (?) and pale blue orthoclase; which last is — 
actually imbedded in the lime,—a most unusual occurrence. 
* In the Chemical News, Feb. 17, 1871, Mr E. C. C. Sranrorp gives the following analysis of the 
dark green crystals imbedded in the pink matrix of the Tiree marble :-— 

Silica, ~ : ? ‘ 60° 
Alumina, 2 : : 22°18 
Ferric Oxide, . ; : 3°42 
Manganous Oxide, . i tr. 
Time, 2 : ‘ : 11°64 
Magnesia, : : ‘ 3°32 
100 - 56 
which analysis is said to correspond with some already published of aluminous hornblende, and to prove 
these crystals to be hornblende. 
It has first to be remarked that Jammson, Maccutxocs, and all mineralogists who have examined 
these crystals recognise them as, without doubt, augite. Second, that this analysis of the same sub- 
stance as that noted above, presents an extraordinarily discordant result therewith. And lastly, that 
in no particular whatever, except in the quantity of lime, does it agree with any one of the 52 analyses 
of aluminous hornblendes published by Dana. In hornblende, alumina, when present, replaces silica ; 
but, without even deducting the 22 per cent. of alumina, the silica here is in excessive amount. 

