FLUOR SPAR. 
376 
two extremes. The crystals are often very large, 
and are principally of a white, violet, blue, green, 
yellow, or rose colour. Among these varieties there 
is one in Siberia of a violet colour, which inflames, 
when thrown on burning coals, and gives a beauti- 
ful green light. Pallas has discovered another va- 
riety in Catharinenburg, of a pale violet spotted 
with green : pieces of this spar are so phosphores- 
cent that the heat of the hand is sufficient to make 
them throw out a white glare, while boiling water 
produces a green light; and if the experiment is car- 
ried further, by throwing some in the fire, bright 
blue flashes will be produced which extend to some 
distance round the place. This remarkable pro- 
perty in fluor spar has been ingeniously exhibited 
bv an officer of some mines in Russia. We are in- 
•/ 
formed by Patrin, that he has encrusted the stove 
of his principal apartment with several pieces of 
fluor spar, which, when the stove becomes heated, 
throw out a coloured glare that at night has a 
very pretty effect. “ I was accommodated with 
this chamber,” says Patrin, “ and not being aware 
of the effect, was agreeably surprised with this 
singular illumination. The light spread by the 
spar was a beautiful mixture of blue and green, 
and quite sufficient to render objects visible in the 
dark.” 
But the most singular property of fluor spar, and 
that which has more particularly excited the at- 
tention of chemists, is the power which one of its 
component parts possesses of dissolving flint. This 
