220 COBALT. 
geal. By so doing, the upper portion, which is fluid, 
is made to run off, and a cake studded with crystals 
will be left. 
247- COBALT is a semi-metal of grey colour with a shade 
of red, brittle, somewhat harder than silver, nearly eight times 
as heavy as water, is attracted by the magnet, and is itself 
capable of being rendered permanently magnetical. 
The ores of cobalt are not numerous, and are, for the most 
part, combinations of this substance with other metals, or of 
its oxides (24) with arsenic, or with sulphuric acid (21). 
The name of this metal implies an evil being, (Kobold y 
German, goblin) and is said to have been given on ac- 
cont of the vapour of arsenic, which issues from it, 
tormenting the miners, and making them believe that 
they are afflicted by wicked spirits. Hence it was once 
customary in Germany to introduce into the church 
service a prayer that God would preserve miners and 
their works from cobalts and spirits. 
Cobalt is found in several parts of Europe, but most 
plentifully in the southern borders of France, and in 
Saxony ; and the cobalt ores of Hesse, although they 
were formerly used for no other purpose than the 
mending of roads, are said now to yield a clear profit of 
nearly 15,000^. a year. Some parts of our own country 
yield this substance in considerable abundance, parti- 
cularly the Mendip Hills in Somersetshire, and a mine 
near Fenzance in Cornwall. 
After the ore is taken from the earth, it is broken 
into pieces about the size of a hen's egg, and the stony 
parts are picked out. The sorted mineral is then 
pounded in mills, and sifted through brass-wire sieves. 
The lighter particles are next carried off by water. 
After undergoing some other preparations, to rid it 
of the impurities and foreign matters with which it is 
connected, it appears in the form of a dark grey oxide. 
The working of the cobalt ores in Germany is consi- 
dered so injurious, on account of the arsenic with 
which they are combined, that much of the labour is 
