PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 263 
first was pure,—the second might not have been totally separated from 
coccolite. | 
1'5 grm. yielded— 1°3 grm. yielded— 

Silica, * 654 *596 
From Alumina, 024 A013 
678 *609 
Silica, Ad 2 46 * 846 
Alumina, 3038 29-313 
Ferric Oxide, . 3 ‘428 2° 306 
Ferrous Oxide, tr. ‘111 
Manganous Oxide, . °68 1°153 
Magnesia, : Bp a 1° 384 
inives4 ; . 5°21 6° 461 
Potash, . oo kilG 7°314 
Soda, pes 497, 3835 
Water, 5 DOO 4.°491 
100 : 06 100 : 209 
The insoluble silica of the first was 2-802 per cent. ; of the second, 3°12. 
One other locality only of this mineral is known. 
pecimens from that locality accord fairly with the above. 
GMELIN’s analysis of two 

Fetlar, Shetland 
Lendalfoot, Ayr 
Glengairn . 
Glengairn . . 
Colour: 

Cream 
Greyish 
Green 
Colour. 

Rose 
Do. 








ANORTHITE. 
Cleavage | Specific = a4 axill ie C 
_Angle. Gravity. Si. Al,O. | Fe,0.) Fe. | Mn. 
3°099 || 46°92 | 30°77 tr. 
86°42 2°761 || 44°22) 31°44 /1°95) ... 
2.958 || 46°42 | 21°86] ... |5°92) 69 
LATROBITE. 
Cleavage | Specific fa cre cel] 00 : 
Angle. Gravity. Si. Al,O. |Fe,0.| Fe. | Mn. 
45°2 | 31°04 |3°43) tr. | °68 
46°87 | 29°31 |2°31) *11)1°15 







Total. 

100°06 
100°21 
In reviewing the results of this extensive series of analyses, the first point 
calling for consideration is the light (if any) which is thrown by it on the ever- 
