d into two such opposite substances, whereof one is combustible,
and the other eminently the contrary. To solve these two questions, it
is necessary to be previously acquainted with the analysis of the
fermentable substance, and of the products of the fermentation. We may
lay it down as an incontestible axiom, that, in all the operations of
art and nature, nothing is created; an equal quantity of matter exists
both before and after the experiment; the quality and quantity of the
elements remain precisely the same; and nothing takes place beyond
changes and modifications in the combination of these elements. Upon
this principle the whole art of performing chemical experiments
depends: We must always suppose an exact equality between the elements
of the body examined and those of the products of its analysis.

Hence, since from must of grapes we procure alkohol and carbonic acid, I
have an undoubted right to suppose that must consists of carbonic acid
and alkohol. From these premises, we have two methods of ascertaining
what passes during vinous fermentation, by determining the nature of,
and the elements which compose, the fermentable substances, or by
accurately examining the produces resulting from fermentation; and it is
evident that the knowledge of either of these must lead to accurate
conclusions concerning the nature and composition of the other. From
these considerations, it became necessary accurately to determine the
constituent elements of the fermentable substances; and, for this
purpose, I did not make use of the compound juices of fruits, the
rigorous analysis of which is perhaps impossible, but made choice of
sugar, which is easily analysed, and the nature of which I have already
explained. This substance is a true vegetable oxyd with two bases,
composed of hydrogen and charcoal brought to the state of an oxyd, by a
certain proportion of oxygen; and these three elements are combined in
such a way, that a very slight force is sufficient to destroy the
equilibrium of their connection. By a long train of experiments, made
in various ways, and often repeated, I ascertained that the proportion
in which these ingredients exist in sugar, are nearly eight parts of
hydrogen, 64 parts of oxygen, and 28 parts of charcoal, all by weight,
forming 100 parts of sugar.

Sugar must be mixed with about four times its weight of water, to render
it susceptible of fermentation; and even then the equilibrium of its
elements wo