Barbour County index. [volume] (Medicine Lodge, Kan.) 1880-current, 1888-11-21
. ALUM AND ITS USES.
a Crystalized Substance Valuable In Many
Totally Different Ways.


Crystalized Substance Valuable In Many
Totally Different Ways.
To the popular apprehension the
word alum describes a white, bitter
astringent which is sold at drug stores
and used in the household for sore
Threats and in commercial operations
as one OF the chemicals employed in
dyeing. Scientifically the word de-
scribes any one of considerable num-
Der OF chemical substances Of different
composition, but having their in
/ gradients combined in the same gener-
nj way. All alums contain sulphuric
acid as one ingredient and some alkali
rs a second, while the commonest form
Of alum contains aluminium as a third
The alkali may be potash, soda, am
monia or lithia, while the metallic
base may be aluminium, chromium or
iron. The commercial alum has a
potash alkali, and aluminium for It's
other base. In fact the name alumni
mum is derived from alum. Other
alums take their names from their
leading bases. Thus ammonia alum
has ammonia for an alkali instead of
I potash, and iron and chrome alums
have iron and chromium in place Of
aluminu IN.
/ As is well known, alum is a power
ful astringent and more or less attracts
organic matter. On account OF this
first quality 1t is largely in medical
use, and on account OF the latter 1t is
extensively used in filtering impure
water. There is hardly town or city
In the United States or Europe whose
water supply is contaminated with
drainage or sewage where IL is not the
custom TO employ the alum process for
( publication. IL has been definitely
settleG by the special investigation of
the American and all the European
\ governments that the very small
amount OF alum left in the water by the
process is not in the least injurious to
tho system.
A larger use OF ordinary alum is
found in dye and print works, where it
I Is known as a mordant. The curious
/ application of this word comes from
/ the fact that il cites" 1t does not
bite the goods, but bites the dyes into
the goods.
A second variety is known as Ro-
man alum, which varies from yellow
10 brownish red in color. 1t contains
iron and aluminium as its metallic base.
II came, originally, only from Italy, as
| indicated by its name, but Is now made
AZ any alum works where there is a
/ demand for il. IL has had for long
lime q high reputation for its medic
nal qualities, especially in cases OF
| luinsy sore throat, now known as
iiphtheria, and scientific investigation
aas shown that there was some truth
N the old belief that the small amount
of iron which the Roman alum con-
aims does increase its efficacy.
At one time both Roman and ordi-
nary alum were used for picking and
preserving different kinds of meats
md fish, but in this direction alum has
been entirely displaced by refrigera-
ion, salicylic acid and other modern
Methods.
A third alum is more of a curiosity
{ is chrome alum, into the compost
lion of which enters that peculiar
metal, chromium. This gives it an
exceedingly beautiful color. One in
eresting use to which this alum is put
$ the making of the finest green
'olor known. This color is OBJ
aimed by exposing an ammonia
and chromium alum to high de-
gree OF heat The heat drives out
the sulphuric acid and the ammonia,
and leaves perfectly pure and exquis-
,tely beautiful chrome green color. 1t
seems a roundabout way to treat the
chromium, but it is in reality the east
est and cheapest way, for the crystal
lzation OF the alum frees the metal
from all impurities, and then by elimi-
mating the acid and ammonia pure
residuum can be obtained. An inter
| ssting use OF this color is the printing
Of greenbacks and the finest of gov
ornamental bonds.
A fourth. most important, ammonia
alum is now largely used is the manu-
tacture Of the finest baking powders.
Its use is based upon the remarkable
chemical action which takes place
when it is mixed with soda in powder
and baked in the oven. By the action
OF the heat the ammonia is expelled,
and the alum by its destruction neutral
ICES the action Of the soda. 1t has
been popular fallacy that the baking
! powder leaves residuum of alum in
the bread, but this, as explained, is
the opposite of the truth.-M y. Matt
and Express.