Bristol news. [volume] (Bristol, Va. & Tenn.) 1867-189?, 1869-07-23
HOW annAIR MADE.

In the domestic economy of the good
housewife, Bicai Donate of Soda is ole
of the articles of most f.cyuent use.
Aud day seldom passes, good. reader,
but that ia bread, cake, pes or pastry,
you eat--not soda precisely, bat the in
visible aud harmless air, into which
through the heat of the oven and GER
tain chemical combinations, the once
palpable aud distastcful powder has
been changed. Like many other arti
cles of most ordinary use, tho process
of its manufacture aud the chemistry
Of its operation are not in general we'll
understood, and SO wo will thy briefly
and plainly to describe them.
Common salt, or, as the chemists
name it, Chloride of Sodium, is the
great source of supply whence Soda is
derived. Immense quantities are used
for this purpose; for, aside from that
required by the bread makers, other
branches Of manufacture consume far
greater amounts. The first step in the
process of making b rcarbonate Of soda
is to mix sulphuric acid with common
salt. A violent oferyesseneo cnsues,
and hydrochloric, or muriatc acid is
evolved. When the action has nearly
subsidized. heat is applied to the vessel
containing the mixture, the acid driven
off, and dry mass remains, which is
sulpha,e Ct soda, or perhaps more
commonly known as Glauber's salt
The dry mass thus obtained is, however,
not cnemicaAy pure, as it usually cou-
taiDs trace Of acid by dissclving il
iu water, noutraliEing the acid with
carbonate Of lime. and allowing tho So
luton TO crystalline, pure sulphate OF
soda my be oil a'ucd. The muristio
acid which results from the process
above described is saved, and made II
source of profit in the manuf u
The neAt step is to convert the sui
plate into the carbonate of soda. To
effect this, perfectly dry sulphaie is
mingled with some carbouaceuus SUBJ
Stance, as coal, or sawdust ami lime the
whole placed in u owerfu! furnace, and
brought into state Of fusion together,
The resulting mass is called btdck ash
aud eontaines about twenty per cent
of carbonate Of soda. To obtain thi
pure, the mass is broken fine, lixiviated,
aud the liquor, after being condensed
by Boiling, produces the oarbOuate by
Capitalization, This is known in com.
merce as Soda Ash.
To obtain purer carbonate for the
manufacture OF the bicarbopate, and Ger.
tain other manufacturing purpos $, the
soda ash is dissolved in hot water up 10
the point of saturation, and the solution
run into shallow paus, where i, rests
until capitalization is efrec'el.
One more process completes the trans.
formation Of salt into bi carbonate Of
soda. The crystals of the carbonate
are placed in shallow wooden trays,
nhd packed up ia tiess in the carbona,
ting rooms. These rooms are made OF
brick, and are sir.ight WHOM closed
When filed with the trays of erytals,
the doors are closed aud valves opened,
which admit pure carbonic acid gas
This displaces the air. which passes off
q roSgh valve. After ten or twelve
days exposure TO the gas tho mass is
dried in kiln under moderate heat.
IL comes from thence in erusty state
and undergoes grinding in suitable
mills. Ii is thou in the form Of fine
white powder, familiar to all who have
penetrated the precincts Of the kitchen.
Rnrh Acc Yorker