But the scattered cometic bodies which returned to the sun's
neighborhood in 1668 and 1887 speak probably of millions of years which
have passed since first this comet was formed. It would be a matter of
curious inquiry to determine what may have been the condition of our
sun, what even his volume, at that remote epoch in history.
* * * * *
THE ISOLATION OF FLUORINE.
The element fluorine has at last been successfully isolated, and its
chief chemical and physical properties determined. Many chemists,
notably Faraday, Gore, Pflaunder, and Brauner, have endeavored to
prepare this element in the free state, but all attempts have hitherto
proved futile. M. Moissau, after a long series of researches with the
fluorides of phosphorus, and the highly poisonous arsenic trifluoride,
has finally been able to liberate fluorine in the gaseous state from
anhydrous hydrofluoric acid by electrolysis. This acid in the pure state
is not an electrolyte, but when potassium fluoride is dissolved in it, a
current from ninety Bunsen elements decomposes it, evolving hydrogen
from the negative and fluoride from the positive electrode.
[Illustration:
(+) (-)
| |
| |
__/_|_\_A __/_|_\_A
| | | | | |
|____|____| |____|____|
| | | | | |
_____| | | | | |_____
/ ---- | | | | -----\
// | | | | | | \\
|| F |===|===| |===|===| H ||
|| |- -|- -| |- -|- -| ||
|| | - | - | | - | - | ||
|| |- -|- - \_________/ - -|- -| ||
|| | - | - - - - - - - - - | - | ||
// \___________________________/ \\
]
The apparatus employed in this process is constructed of platinum, and
is made in the form of a U tube, as shown in the accompanying
illustration, with fluorspar stoppers, through which the battery
terminals, made of platinum iridium alloy, are led.
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