When man feeds on sugar he splits it up by the aid of air into water and
carbon dioxide in this fashion:

C_{12}H_{22}O_{11} + 12O_{2} --> 11H_{2}O + 12CO_{2}
cane sugar oxygen water carbon dioxide

When sugar is burned the reaction is just the same.

But when the yeast plant feeds on sugar it carries the process only part
way and instead of water the product is alcohol, a very different thing,
so they say who have tried both as beverages. The yeast or fermentation
reaction is this:

C_{12}H_{22}O_{11} + H_{2}O --> 4C_{2}H_{6}O + 4CO_{2}
cane sugar water alcohol carbon dioxide

Alcohol then is the first product of the decomposition of sugar, a
dangerous half-way house. The twin product, carbon dioxide or carbonic
acid, is a gas of slightly sour taste which gives an attractive tang and
effervescence to the beer, wine, cider or champagne. That is to say, one
of these twins is a pestilential fellow and the other is decidedly
agreeable. Yet for several thousand years mankind took to the first and
let the second for the most part escape into the air. But when the
chemist appeared on the scene he discovered a way of separating the two
and bottling the harmless one for those who prefer it. An increasing
number of people were found to prefer it, so the American soda-water
fountain is gradually driving Demon Rum out of the civilized world. The
brewer nowadays caters to two classes of customers. He bottles up the
beer with the alcohol and a little carbonic acid in it for the saloon
and he catches the rest of the carbonic acid that he used to waste and