Daily Yellowstone journal., 1891-02-05
cHANcEAeLE STONES
Peouliar Actions OF ParAdoxieAl Pebbles
In the British Museum.

In the British Museum.
Among the thousands of wonderful
things in the British museum none is
more deserving of a description than
tho three little pebbles known to the
geologist of that institution rs the
''changeable stones" The largest of
the three Is about the size of a cherry
stone and Of the same form. perhaps a
little more ovate. Lying in its little
glass case it appears to be perfectly
opaque and of a yellowish color. Para
doIical as it may seen, it will scratch
glass If it is drawn across it, but can
itself be scratched with common pen
knife. The various acids have no eff
feet whatever upon it, but strange to
relate, placed in water it o becomes
perfectly transparent and Of a bnauu-
full amber color.
The change begins almost immedi-
ately after the immersion at one end OF
the ovate i'm the form of a minute shot
or bead, being in this way wholly I'M
like the two smaller ''changeable
stones. in which the transparency be
gins around the edges and gradually
envelopes the entire stone. In the
large one thc little globe like spot in
creases by degrees until the stone be-
uniformly clear throughout
When removed from the water the end
frt TO become transparent is first to
become opaque. the dark colored globe
gradually hiding the Transparency OF
the whole stone.
Bergman. Veltheim, Magellan and
Buchanan. all voluminous writers upon
the hydrophanes and other changeable
stones. tell Us that some Of the steatites
exhibit changes quite as astonishing a.
those shown by the three pebbles in
England's great national curiosity shop.
Buchanan and Neltheim were the first 10
particularly inquire into the nature Of
steatite and stones of similar compost
ton. Their report on the remarkable
changes wrought upon apieceof steatite
upon which they were experimenting
may not be wholly uninterestingt TO read
es who have a taste for the curious in
its manifold forms.
IL is as follows: AS as the
stone was placed in the water we noted
a peculiar musty smell, also that sew
eral air bubbles rose TO the surface of
the water. Soon the first stont showed
signs Of becoming transparent, then
several Others we're dropped into the
same vessel. Some of them became
eoIorless AZ soon as they were thor
oughly dampened; others took ON a
more OF less deep yellow color; some
acquired a beautiful ruby hue, and
others still the color Of mother-of-
pearl or Of a BLUSH opal. Whatever
be the color Of the liquid I'm which the
/ hydrophane Is immersed, it gains only
its usual degree of Transparency, with
the color PECULIAR to It. When We look
at it in its moist state We perceive a
luminous point, varying IN its situation
as the position Of the eye n altered.
The ancients also noticed the peculiar
little luminous spot in the steatites and
other hydrophanea which was the
cause of their calling such stones Ocu-
lus Mund, they thinking the spot the
image Of the sun. According 10 Buck
man, il is not the immediate picture Of
the sun. but a reflection refracted into
the stone by the direct rays Of old Sol,
which may serve to remind Us that the
ancients knew a thing or two after all
st. Louis Republic.