26 On some Geological Agents. [Sess. 
moment’s consideration unless on a windy day, when we get 
our eyes, mouth, and nostrils filled with it. It forms con- 
siderable areas round our coasts, called links. The golfer 
knows and loves the links, but the ordinary golfer knows 
nothing about the natural history of the sand that forms these 
links over which his ball rolls. All that he knows and cares 
for about sand is its “bunkers.” That the sand which forms 
these tracts of land was blown in from the sea-shore is 
certain. In fact, it is land recovered from the sea—the wind 
blowing the sand inland after the tide has retired from the 
shore. On the East Coast we have large stretches of such 
land—one of the largest, called Tentsmuir, extending from the 
mouth of the Eden to the mouth of the Tay. On the north 
side of the Tay we have Barry Links, and on the south of the 
Eden the ever-famous golf-links of St Andrews. Much of the 
sand has been brought by these two rivers. 
It is not very clear how all this sand was accumulated, or 
by what agency the rocks were reduced from the solid to this 
granular condition. The only way we can account for it is 
the dissolving of the softer materials—felspar, &c.,—leaving 
the quartz particles to be carried away by running water. 
Sand in motion, by reason of the hardness of the silica, is 
an agent of tear and wear. I have here a few specimens of 
its polishing action on rock, by which you can see that it was 
the origin of the sand-blast so much used nowadays in the 
industrial arts. It is an abrading agent when carried forward 
by running water; and driven by wind and wave against the 
sea-cliff, it undermines it, bringing down'large masses of rock, 
which will likewise be ground into sand and utilised in the 
Same manner and for the same purpose of destruction. 
In some countries—France, for instance—large tracts of 
valuable land have been overwhelmed by the inland move- 
ments of sand. In our own country, in Morayshire, some ten 
square miles of the best arable land in the county were 
covered to a great depth by sand driven in from the sea- 
shore. A partial cause of the disaster was “the bad prac- 
tice of pulling bent and juniper.’ So said an Act of the 
Scottish Parliament, dated July 16, 1695. 
The sea is a geological agent of the highest importance. It 
is in a state of perpetual war against the land. Its powers of 
