PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 499 
Its surface, where exposed, was ochre yellow, softer, and serpentinous 
looking. It occasionally seemed to pass into ordinary dark sahlite, and was 
sometimes associated with massive green serpentine carrying crystals of talc ;— 
this serpentine was well crystallised in the form of augite. 
When steeped in weak acid this totaigite became white. Its specific 
gravity lay between 2° 84 and 2° 893. 
1:76 grammes yielded— 
Silica, : - °631 
From Alumina, . * 004 
* 63-1. = 36° 193 
Alumina, . 5 : : * 264 
Ferric Oxide, . : i * 286 
Ferrous Oxide, . ‘ oe “22958 
Manganous Oxide, . : * 454 
Lime, : ; : Syl LO AY: 
Magnesia, . : . 45°57 
Potash, . : . ; "252 
Soda, : : ; : *424 
Water, . : : Sloe 
99 - 973 
Insoluble silica, 2: 04 per cent. ; loss in bath, «568 per cent. 
These two are unquestionably to be ranked as the same substance ; the 
second had certainly the appearance of being an intermediate stage in the 
conversion of sahlite into serpentine ; the difficulty in coming to the conclusion 
that it was so, lies in the immediate association of perfect serpentine, and 
also in the supposed intermediate substance containing more magnesia than 
that requisite for the perfected change. 
Schiller Spar. 
28. This variety—new to Britain—I first found in two serpentinous masses 
of rock which lie imbedded in the sand, below high-water mark, a few yards to 
the north of the Black Dog rock, north of Aberdeen. It has, more lately, been 
found by Professor Nicox and myself in two quarries to the east of Craigie, near 
Beauty Hill, some eight miles north of Aberdeen. 
It is in every way identical in appearance with the Basta specimens, being 
perhaps somewhat larger in the glimmering foliations. These foliated portions 
were, in the Black Dog specimens, of a fine leek-green colour; in those from 
