52 COMMON SAND. 
near Chemnitz, in Saxony ; and, in the Electoral Ca- 
binet at Dresden, there is part of the trunk of a tree, 
from the same place, which measures five feet in length 
and as manj? in thickness. 
Woodstone is in considerable request by lapidaries. 
It takes a good polish, and is made into beads for neck- 
laces, and other female ornaments. In the East Indies 
it is generally called Petrified Tamarind Tree. 
88. COMMON SAND is a granulated Kind of quartz ; 
or consists of rounded grains of small size, which have a vitreous 
or glassy surface. 
It is usually of white or yellowish colour; but is sometimes 
blue, violet, or black. 
In the torrid regions of Africa and Asia there are 
immense tracts of desert covered only with sand, so 
dry and light as to be moveable before the wind, and 
to be formed into vast hills and boundless plains. These 
are incessantly changing their place, and frequently 
overwhelm and destroy the travellers whose necessities 
require them to enter these dreary realms. 
Sand has numerous uses. When mixed in due pro- 
portion with lime, it forms that hard and valuable ce- 
ment called mortar. Melted with soda (200) and 
potash (205) it is formed into glass; white sand being 
used for the finer kinds, and coarse and more impure 
sand for bottle glass. A very pure kind of sand 
which is found in Alum Bay, on the west side of 
the Isle of Wight, and on some parts of the coasts of 
Norfolk, is in great request by glass-makers. Sand is 
also employed in the manufacture of earthenware ; a"nd 
its utility "in various branches of domestic economy, 
but particularly for the scouring and cleaning of kitchen 
utensils, is well known. In agriculture sand is used 
by way of manure, to all soils of clayey lands ; as it 
renders the soil more loose and open than it would 
otherwise be. The best sand for this purpose is that 
which is washed by rains from roads or hills, or that 
which is taken from the beds of rivers. 
