Urbana union. [volume] (Urbana, Ohio) 1862-1872, 1869-08-04

IL the domestic economy of the good
housewife, bicaTbOnate of soda is one of
the articles of most frequent use. And
day seldom passes, good reader, but
that in bread, cake, pies, or pastry, you
eat-nOt soda precisely, but the invisible
and harmless air into which, through
the heat of the oven and certain chemi-
cal combinations, the once palpable and
distasteful powder has been changed
Like many other articles Of most OTdi-
nary use, the process Of its manufacture
and the chemistry Of its operation, are
not in general well understood, and so
we will try briefly and plainly to de-
scribe them. Common salt, OF, 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 re-
Quired by the bread makers, other
branches of manufacture consume far
greater amounts. The first step in the
process of making bicarbOnate of soda
is to mix sulphuric acid with common
salt. A violent effeTvescence ensUes,
and hOdrOchlOric or mUriatic acid is
evolved. When the action has nearly
subsidized, heat is applied to the vessel
containing the mixture, the acid driven
off and a dry mass remains, which is
sulphate of soda, or perhaps more COM
monty known as Glauber's salt. The
dry mass thus obtained is however, not
chemically pure, as it ustally contains a
trace of acid. By dissOlving it in water,
neutraliZing the acid with carbonate of
lime, and allowing the solution to cTys-
taliZe, pure sulphate Of soda may be
obtained. The muriate acid which re-
suits from the process above described
-, covro1 01nI ms 0Gn n nf 10rnfif
the manufacture. The next step is to
convert the sulphate into the carbonate
of soda. To effect this, perfectly dry
suIphate is mingled with some carbon
aceOus substance, as coal, or saWdust
and lime, the whole placed in 4 power
full furnace, and brought in a state of
fusion together. The resulting mass is
called black ash, and contains about
twenty per cent. of carbonate of soda.
To obtain this pure, the mass is broken
fine, liXiviated and the liquor, after be-
ing condensed by boiling, produces the
carbonate by crystaliZatiOn. This Is
known in commerce as soda ash. To
obtain a pUTer carbonate for the manu-
facture Of the bicarbOnate, and certain
other manufacturing purposes, the soda
ash is dissolved in hot water up to the
point of satuTatiOn, and the solution run
into shallow pans, where it rests until
| crystalizatiOn is effected. One more
! process completes the transformation of
salt into bicarbOnate of soda. The cTys-
/ tails of the carbonate are placed in shall
/ low wooden trays, and packed up in
tiers in the carbOnating rooms. These
rooms are made of brick, and are air
/ tight when closed. When filled with
the trays of crystals, the doors are clos
| ed and valves opened, which admit pure
carbOnic acid gas. This displaces the
air, which passes off through a valve
After ten or twelve days exposure to
the gas, the mass is dried in kiln Un-
der moderate heat. ItcOmes from thence
in a crusty state, and UndergOes grind
ing in suitable mills. 1t is then in the
form Of Il fine white powder, familiar to
all who have penetrated the precincts of
the kitchen.-RJTdL NCjC Yorker.