ten, hydrogen; and ten, oxygen—though
some reckon the two last at eleven. In
fermentation these elements are dislodged,
so to speak, from the position they hold, one
to another, and then a re-arrangement of
them takes place. Part of the carbon of the
sugar unites with most of the oxygen so as
to form carbonic acid, which flies off in gas.
The rest of it combines with all the hydrogen
and some of the oxygen, and becomes alcohol,
or spirit, the production whereof in infusion
of malt, converts it into that generous and
invigorating beverage on the philosophy of
which I have now the honour of addressing
you. Alcohol consists of four proportionals
of carbon, six of hydrogen, and two of
oxygen. The proportions of these elements
one to another in sugar and alcohol, as well
as other things, are made out by separating
one from the other according to art, in ways
which it would take too long to describe,
called Analysis. Well; you see fermentation
is a sort of inward commotion ending in a
new constitution; a sort of natural revolution
in point of fact. Alcohol is formed in making
wine, and all strong drinks, in the same
manner as in brewing. A certain quantity
of it, perhaps you may know, is even
produced in fermenting bread. This is mostly
lost in the baking; but some years ago there
was a company formed to supply the Public
with cheap bread, in the hopes of being
enabled to afford to sell it at a lower price
by collecting the spirit that is generally
wasted. Whereupon a baker, who was up to
snuff a great deal more than to chemistry,
set up a shop where he professed to sell
bread at the same rate as the company, with
the gin in it!

"The carbonic acid given off from beer while
fermenting, is what makes it so dangerous to
go down into vats, and sometimes occasions
death by this being done without precaution.

"The proper plan is to send a candle down
first; if there is much carbonic acid it puts
it out. So, if you let a light down into the
tun-tub, over the fermenting liquor. All the
inside of the tub, above the liquor, while it is
working, is full of carbonic acid gas; and if
you dip a cup into the gas gently, you can
ladle it out, and then if you turn the cup
upside down over a candle you extinguish
it as completely as if you were to pour
water upon it, by that means astonishing the
weak minds of spectators in a considerable
degree.

"When the froth, or yeast, ceases to be
formed on the surface of the liquor in the
tun-tub, your wort has become beer, which
you allow to get cold, and then put it into
the cask or barrel. Here the fermentation
still goes slowly on, as is shown by the yeast,
that keeps gradually working out of the cask,
till all the sugar, or as much of it as can be,
is changed into spirit. Beer that tastes
sweet, owes its sweetness to containing
sugar not decomposed, or changed into spirit.
Bottled beer is beer in which the carbonic
acid, made by the decomposition of the sugar,
or other vegetable matter in the beer, is
prevented from escaping by being corked down.

"A liquor, to ferment, requires a certain
amount of heat, not lower than between fifty-
five and sixty-five degrees. It likewise grows
hotter during fermentation; and as carbonic
acid gas is thrown off at the same time, as
from a fire, this makes fermentation seem
somewhat like a burning or combustion.
Only this, which is called the vinous fermentation,
is a sort of burning independent of the
air, the oxygen that feeds it being contained
in the liquor.

"All fermentation in beer—or wine either—
ought to stop with the change of sugar into
spirit. But by being exposed to the air, or
to the action of electricity, and some other
causes, a second fermentation is set up in it.
The alcohol takes in oxygen from the air, and
is changed into acetic acid, or vinegar. This
is the reason why it is so necessary to have
beer-casks thoroughly air-tight; for though
what is called the acetous fermentation is
interesting as a matter of science, to have
one's beer turn sour is a great misfortune, in
a domestic and economical point of view.
What is termed hard beer is beer in which
vinegar, or acetic acid, has begun to form.

"Good beer, then, is a mixture of alcohol and
water, more or less undecomposed sugar,
mucilage, and other extractive matter, carbonic acid,
in greater or less quantity, and those delicate
principles on which flavour depends, besides
the bitter of the hop. To these things there
is added colouring-matter, which is given by
the malt. In porter this is got by malt that
has been roasted almost to charcoal. The
carbonic acid in beer is what its briskness
depends upon. The little bubbles you see in
sparkling ale are composed of this gas, and
without it the beer tastes flat. Old beer is
beer wherein the vegetable matter has been
wholly or mostly decomposed. In mild beer
the decomposition has not been quite
completed. It is a pleasing relish to a pot of
beer to reflect on the chemical facts which
that particular taste in it, which you fancy,
depends upon.

"So much, ladies and gentlemen, for the
chemistry of beer. Now for a word or two
about the druggistry of it. Instead of malt,
sugar, treacle, honey, and other sweet things
may be used—though contrary to law in the
case of brewers—and are so, I fancy, more or
less; without much harm. Wormwood, quassia,
and other bitters, may, in like manner, be
employed in lieu of hops, without poisoning
the consumer. Buckbean, or Menyanthes
trifoliata, is another substitute to be marked
'dangerous.' Aloes has likewise been used for
the same purpose; but, being physic, I think
it had much better be confined to regular
medicinal purposes and not used to doctor
beer with.

"I won't say, however, that beer may never