PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 539 
1:131 grammes yielded— 
Silica, . P : * 466 
From Alumina, . *003 
*469 = 41-467 
Ferric Oxide, . : . ALO NO 
Ferrous Oxide, . 3 eS 
Manganous Oxide, . : "265 
Magnesia, . ; : of Sf dD 
Water, . : ; we 5 
100 + 202 
Loses in bath 1° 557 per cent. 
Here, in the total abstraction of lime and of alkalies, we have a close ap- 
proach to the simplicity of composition of serpentine. The relative amounts of 
silica, magnesia, and water are almost those normal to that mineral; there is 
still, however, a retention of iron. 
31. If serpentine be a mineral incapable of assuming a crystalline form, or 
of having its particles grouped in an approach to a crystalline arrangement, then 
must the fibrous varieties, called chrysotile—which appear like acicular crys- 
tallisations—be pseudomorphic. 
Even in these, however, the abstraction of the iron is not complete. 
Chrysotile of wondrous beauty was found by DupGEon near Hesta Ness, 
_ which terminates the south side of the bay of Gruting, in Fetlar, Shetland. 
It consisted of veins of about one-fourth of an inch in thickness, which 
| yeins—sometimes in double rank—traversed a peculiar granular magnetite. 
The fibres of the chrysolite, as is usual with this mineral, lay transverse to the 
| yein. These fibres were of a golden yellow, tinged with green; they were of 
extreme delicacy and had a brilliant silky lustre. Altogether they constitute 
one of the most beautiful of Scotch minerals. 
1°495 grammes yielded— 
Silica, . : : SS: 
From Alumina, . -016 
- 594 a oo en 
Alumina, . : . a) 096 
Ferrous Oxide, . : ye Wow es 
Magnesia, . 3 : . 41°605 
Water, : : : . 15°659 
100-015 
As the magnetite here is itself saturated with a serpentinous basis, there is 
a possibility that the fibrous structure of the chrysolite may be the result of its 
protrusion, by an exfiltration process, through the interstices of the granular 
