Pure white sugar is the first and greatest contribution of chemistry to the world’s dietary.  It is unique in being a single definite chemical compound, sucrose, C_{12}H_{22}O_{11}.  All natural nutriments are more or less complex mixtures.  Many of them, like wheat or milk or fruit, contain in various proportions all of the three factors of foods, the fats, the proteids and the carbohydrates, as well as water and the minerals and other ingredients necessary to life.  But sugar is a simple substance, like water or salt, and like them is incapable of sustaining life alone, although unlike them it is nutritious.  In fact, except the fats there is no more nutritious food than sugar, pound for pound, for it contains no water and no waste.  It is therefore the quickest and usually the cheapest means of supplying bodily energy.  But as may be seen from its formula as given above it contains only three elements, carbon, hydrogen and oxygen, and omits nitrogen and other elements necessary to the body.  An engine requires not only coal but also lubricating oil, water and bits of steel and brass to keep it in repair.  But as a source of the energy needed in our strenuous life sugar has no equal and only one rival, alcohol.  Alcohol is the offspring of sugar, a degenerate descendant that retains but few of the good qualities of its sire and has acquired some evil traits of its own.  Alcohol, like sugar, may serve to furnish the energy of a steam engine or a human body.  Used as a fuel alcohol has certain advantages, but used as a food it has the disqualification of deranging the bodily mechanism.  Even a little alcohol will impair the accuracy and speed of thought and action, while a large quantity, as we all know from observation if not experience, will produce temporary incapacitation.

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