ring the formation of alcohol,
the latter will contain less carbon and oxygen than sugar does;
therefore hydrogen must be the prevailing principle of alcohol.

MRS. B.

It is exactly so. And this very large proportion of hydrogen accounts
for the lightness and combustible property of alcohol, and of spirits in
general, all of which consist of alcohol variously modified.

EMILY.

And can sugar be recomposed from the combination of alcohol and carbonic
acid?

MRS. B.

Chemists have never been able to succeed in effecting this; but from
analogy, I should suppose such a recomposition possible. Let us now
observe more particularly the phenomena that take place during the
vinous fermentation. At the commencement of this process, heat is
evolved, and the liquor swells considerably from the formation of the
carbonic acid, which is disengaged in such prodigious quantities as
would be fatal to any person who should unawares inspire it; an accident
which has sometimes happened. If the fermentation be stopped by putting
the liquor into barrels, before the whole of the carbonic acid is
evolved, the wine is brisk, like Champagne, from the carbonic acid
imprisoned in it, and it tastes sweet, like cyder, from the sugar not
being completely decomposed.

EMILY.

But I do not understand why heat should be evolved during this
operation. For, as there is a considerable formation of gas, in which a
proportionable quantity of heat must become insensible, I should have
imagined that cold, rather than heat, would have been produced.

MRS. B.

It appears so on first consideration; but you must recollect that
fermentation is a complicated chemical process; and that, during the
decompositions and recompositions attending it, a quantity of chemical
heat may be disengaged, sufficient both to develope the gas, and to
effect an increase of temperature. When the fermentation is completed,
the liquid cools and subsides, the effervescence ceases, and the thick,
sweet, sticky juice of the fruit is converted into a clear, transparent,
spirituous liquor, called wine.

EMILY.

How much I regret not having been acquainted with the nature of the
vinous fermentation, when I had an opportunity of seeing the process!

MRS. B.

You have an easy method of satisfying yourself in that respect by
observing the process of brewing, which, in every essential
circumstance, is similar to that of making wine, and is really a very
curious chemical operat