Herald and tribune. [volume] (Jonesborough, Tenn.) 1869-current, 1897-10-06
How the Modern Process of Aluminium Manu-
facture was Discovered.

1
facture was Discovered.
Tho American Monthly Rview of
Reviews for October tells the story of
the invention by Charles NJ. Hall,
graduate of Oberlin College of the pro-
cess now employed for the production
OF aluminium on an extensive scale.
After speaking of Mr.. Halls college
career and graduation, the Review
writer says:
With only the most meager equip
ment, without financial resources, and
with little encouragement from friends
or associates, Hall now entered on se-
ries of experiments which in less than
a year resulted in the discovery of what
proved to be cheap, practicable and
efficient process for the extraction of
aluminium. Hall has himself said that
his fist work in this direction did not
have reference to electrolysis as the
solvent. AT intervals during his col.
iege course he-had experimental In va.
rious crude attempts to produce the
metal by methods which his reading
on the subject had suggested. He had
familiarized himself with all that had
been written about aluminium, and un.
derstood thoroughly the problem of its
production.
In 1884 he spent several weeks in an
attempt to reduce the oxide of alumi-
num by carbon at high temperature
with the aid of other reagents. Altbo'
Ia these experiments he used blast
furnace capable of fusing platinum, he
failed to accomplish the object in view
and 1t was then he turned to electroly.
sis as the only practicable method. 1t
was natural that at first he should
wish to make trial OF the process then
known of producing aluminium by the
electrolysis of the double chloride. He
says that he determined to follow out
this process carefully, and and if pos
sible to improve it. Whether or not he
would have succeeded in his efforts to
perfect this process must remain q mat.
ter OF mere speculation. In October,
1850, four months after graduation from
college, he evolved an entirely new
plan OF procedure. Instead of apply
ing electricity directly to the chloride
IA method which had already been
tried and found wantlng-he would en-
deavor to find stable solvent for
alumina itself 1.-THE oxide) and would
then electrolyze the pure aluminium
from the solution. 1t was. of course,
desirable that the metal shoald be dis
solved at a reasonably low temperature
and that the solvent itself should be
practically unaffected, so that the OK.
ide might be added continuously as
fast as it was decomposed by the cur
rent. Hall believed that he would find
such solvent in the fouride of mag
nesium, sodium and potassium. He
found that all these compounds were
extremely difficult to fuse, and that
they did not, when fused, dissolve the
alumnia appreciably. These facts he
might have inferred, perhaps from the
descriptions of these minerals given in
the books, but nothing short of the ac-
tual experiment and observation would
satisfy him, and he took nothing for
granted. In his search for solvent
he finally determined to test the double
fiuoride of aluminium and sodium
(cryolite. Diville, who had expert
mented with this mineral thirty years
before, had apparently never discovered
that it was solvent, when fused, of
alumina. II it could be proven to be
such solvent, the most difficult part
of the quest seemed in fair way to be
solved.
Hall g first experiments with cryolite
were not altogether satisfactory to him,
but he attributed each failure to de-
fects in his apparatus. He fused some
cryolite in clay crucible, dissolved
alumina in this bath, and passed an
electric current through the solution.
On the carbon rod which served as the
negative electrode substance was de
posted which had the appearance of
aluminium, but it was not the pure
metal, A portion of the clay from
which the crucible was made seemed to
yield its silica to the bath, and thus
the product was rendered impure. The
only way to obyiate this was to employ
an insoluble lining for the crucible.
The first experiment with a carbon
lined crucible was successful. BY the
aid of seven cell Grove battery, with
In two hours time, reasonable
amount of aluminium of high degree
OF purity was obtained.
Mrs. Smith Woodbridge, of Kimble,
KY, was so afflicted with her throat
for over two years that she could not
speak above whisper. After she
used the first bottle Of DIR. Bells Pine
Tar Honey she could talk as well as
ever. and the case Is such wonderful
cure that her neighbors come In to see
for themselves and are astonished to
hear her talk. Sold by all druggists.
Labor for Postal Savings Banks.
The State Federation OF Labor in ses.
sion at Bloomington has adoptedits in
dorsement to the agitation for estab
lishment of postal savings banks. I,o.