Manchester, then containing ninety thousand people,
did not provide work for a single baker. Now,
the bakers have nearly the whole bread trade of
the towns of England to themselves, and it is
well that they should have it, and should make
the best of it.

Before we can tell how they are to make the
best of it, we have to know less vaguely what
is meant by some of the words we have here
been using.

Milk and bread are the only perfect articles
of human food—that is to say, the only articles
which contain in themselves all the elements
required for the support of the body. Bread is
a better food than milk for the adult, because it
employs the teeth and all the parts of the body
to which they are a portal in the work for which
they were created. Spongy bread, since it
contains forty per cent. of water, unites meat and
drink, having therein advantage over biscuit.
It has advantage also in its bulk, for the stomach
was made to act upon food in bulk, and will not
do its work in the best manner if it be not duly
distended. It has advantage also in presenting,
by its cellular structure, an enormous surface
to the necessary action of the saliva. Men
long confined to biscuit acquire strong desire
for spongy bread, and the like desire is felt by
invalids, from whose diet it has sometimes to be
excluded.

The sponginess of bread is usually produced,
as we have said, by fermentation. The granules
of starch in the wheat flour are so acted upon
as to be made to give off a minute quantity of
carbonic acid gas; this being retained by the
tenacity of the surrounding gluten, causes the
mass of dough to swell up and become spongy.
There are in a hundred parts of wheaten flour
about seventy-two of starch and extractive,
with ten of gluten, two of fat, and sixteen of
water. It is upon the gluten and the starch and
extractive that the structure of bread wholly
depends. The gluten is sticky as glue and
elastic, the starch granules have no more
coherence than so many grains of sand. Gluten
wetted with water and kept at a hot summer
temperature of about eighty-five degrees will
soon begin to decompose, and will change any
starch with which it is in contact, first into
dextrine and afterwards into grape sugar. If the
contact is maintained for some days, organic life
commences, and at the same time the grape
sugar is changed into alcohol and carbonic
acid. The carbonic acid, in endeavouring to
escape, causes the dough to swell. This is
the chemistry of that old method of leavening
the dough, still followed in Poland, and
some other parts of Europe. The process is
the same, but quicker, when a small piece of
the dough already fermented is put with that
freshly made, and the hastening is greater still
when use is made of active ferments, such as
ale and beer, yeast, or, most active of all, the
"German yeast."

For this chemical change to take place
uniformly and thoroughly, it is necessary that all
ingredients of the dough should be brought
thoroughly into contact with one another. This
is effected usually by kneading with the arms
and feet, warm and unhealthy work for bakers'
men, and to the eater of the bread sufficiently
disgusting. When the kneading is complete,
each starch granule has a thin coating of moist
gluten, and by their tenacious coats the grains
will all hold firmly together, and throughout the
substance of the stiff dough, chemical action
proceeds evenly.

Now there are certain obvious objections to
this process. The whole object of it is to
procure a development of fixed air to distend the
bread, and this is obtained by a decomposition of
some part of the essential nutritive constituents
of the flour. Part of the nutritive matter of
the starch and gluten suffers decomposition into
ammonia, alcohol, and carbonic acid, while other
portions are changed into constituents liable to
affect injuriously delicate stomachs. The free
acids contained in all fermented bread
frequently disagree with children, always with
dyspeptic people, and there is a liability to second
fermentation in the stomach. The gluten is
deprived of its full power of producing firm and
healthy muscle.

To obviate all these objections, Dr. Whiting
proposed, some years ago, a method of making
spongy unfermented bread. He mixed
intimately with the dough, not leaven or yeast, but
muriatic acid and bicarbonate of soda, in the
proportions that would make common salt, a
requisite ingredient, after giving off the
carbonic acid gas, by which the unfermented and
unaltered dough would be distended. The plan
was an elegant one, and has been freely adopted.
It is the principle upon which alone, until lately,
unfermented spongy bread was made. The
objections to it are the direct introduction into
the bread of chemical ingredients, either of
which would be hurtful if by chance the proportion
were not rightly observed, or the mixture
imperfectly effected. The bread also, when so
made, is less spongy than bakers' bread.

But within the last year or two it has
occurred to another physician, Dr. Danglish, that
by mechanical contrivance the pure fixed air
can be passed into the dough, and that flour
unaltered by fermentation, untouched by any
chemical, unpolluted even by the touch of any
hand, can be made into a perfect form of spongy
bread. Having developed his plan fully, he
took out a patent, and already at Portsmouth
and at Dockhead in Bermondsey extensive
factories are engaged in the production of an
"Aërated Bread," which, as to its substance, is,
we believe, bread made perfect, though it is
possible that there may be hereafter developed a
less costly way of making it.

The patent is worked wholly by steam
machinery, of which we cannot attempt to explain
all the ingenious refinements. The main
principle is easily to be understood. According to
the way usually adopted in producing the same
gas for soda-water, carbonic acid is formed in a
large receiver, far away from the dough.
Thence it is forced into a great copper cylinder,