548 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 
The solution is, to a certain extent, easy: it is very evident that it must 
have been highly protuberent above the gneiss when the ice began its work, 
and that the duration of that work was not sufficient to bring about what may 
be termed the normal result. 
But how came it that the soft rock was thus protuberent? And this is 
what serpentinous change, considered along with other simultaneously acting 
changes, alone can show. 
“Who scalped the brows of old Cairngorm?” “’Twas I,—the Spirit of the 
Storm.” Now, this Spirit, in making free with those poetic fancies called “the 
everlasting hills,” makes use of several kinds of scalping knives. 
Certain of these are chemical, some physical. Among the chemical we 
have the gnawing tooth of carbonic acid, and the rusting fang of oxygen. 
Among the physical there is the solvent soak of water, the expanding heave of 
that water when it becomes ice, the chiselling chip of the sand blast, and, 
more locally, the rasping and the bruising of marine breaching. 
Let us see how they have been operating here, for operate they did before 
the era of the ice,—there could have been no serpentine else. The ribs of 
mother earth, when swathed in ice, must have been as effectually preserved 
from atmospheric change, as are those other ribs which are brought over the 
Atlantic in ice-sheathed holds. 
The result of their operation—of the operation of all yet noticed—is in one 
respect the same. This has been emphatically pointed out by the gentleman 
already mentioned ; they all roughen, one alone smoothes.* It is the function 
of ice alone to ‘‘ make the rough places plain.” 
And the planed surfaces present a fair field for the study of the mode of 
action of the atmospheric agencies, when the re-exposure of the surfaces left 
them again subject to such action. 
That action has been but trifling in amount after all. The hieroglyphics on 
those polished tablets of stone—these glacial Runes “wrought by the hand | 
which works unseen ”—we know were not of yesterday ; but, so sharply tangible 
to feeling as well as to sight are they, that we might almost conclude that 
they were. The thousand years has here been as one day. 
At Canisp and other parts of Sutherland the tracings may be seen to run 
to the brink of what are but greater scratchings after all ;—a trough which lies 
between it and Coul More on the south is 6 miles wide and 1500 feet of clear 
depth ;—another, between the same hill and Quinaig on the north, is 5 miles 
in width and 2600 feet in depth. 
* Water in certain situations appears to polish—as in the rock-runnels of streams, the pot-holes of 
rivers, the back-tow crevasses of the seashore, and some undercut beach rocks or cliffs. In all these 
cases, sand or stones, held in the grasp of the water, have done the work, which was of the nature of 
grinding or chiselling. Most interesting illustrations of simple wave-action, and of this compound 
pummelling and rasping process, are to be seen at low water beneath the Kincraig near Elie. 

