358 



PROFKSSOK HEDDLE ON 



4. From Laggan, Dulnan Bridge, Inverness-shire. 



This was given me by Sir Archibald Geikie. It was got in quartz veins in the 

 limestone quarry. It occurs in pale brown crystals entirely imbedded in the quartz. 

 The crystals are lustrous and well defined ; the associates are chlorite and sahlite. In 

 the near neighbourhood there is much kyanite. The specific gravity is 3*438. 



On 1"2 grammes — 



Silica, .... 



. -463 



from Alumina, 



. -002 





•465 = 38-75 



Alumina, 



28-144 



Ferric Oxide, . 



6-547 



Manganous Oxide, . 



•916 



Lime, . 



22-026 



Magnesia, 



•416 



Water, .... 



3333 



100-132 



Loses in the bath, -155 per cent. 



5. From Loch Garve, Ross-shire. This locality was found by the late W. H. Bill. 

 It is that in which the mineral occurs in much largest quantity in Scotland, and also in 

 much the largest crystals. It occurs in a quartzose vein, which, starting from near the 

 centre of the south shore of the lake, strikes right up the hill for two or three hundred 

 feet. Sometimes it is almost massive, occasionally in crystals of a stouter habit than 

 those of Urquhart. The colour is ash-grey to white, passing to pale yellowish-brown. 

 It is translucent. The specific gravity is 3*268. 



On 1*34 grammes — 



Silica, 













40-066 



Alumina, 













30-834 



Ferric Oxide, 













1-58 



Ferrous Oxide, 













•48 



Manganous Oxide, 













•22 



Lime, 













23-66 



Magnesia, 













•476 



Potash, . 













•504 



Soda, . 













•428 



Water, . 













2-100 



100-348 



Insoluble silica, 2-2 per cent. 



