Page:Popular Science Monthly Volume 82.djvu/573

Rh de vie." Indeed, some believe that "eau de vie" curtails rather than prolongs life, and some there are who go so far as to maintain that "eau de vie" should be called "eau de mort." But this is aside from the subject! It is of interest, however, to note that out of the opinion expressed by Arnaldo de Villaneuva probably grew the prevailing belief in Europe in the efficacy of the daily use of brandy, and to the latter may be attributed the custom of the mint julep or so-called old-age drink prevalent in parts of our own south.

Man, seeking ways of producing alcohol from substances other than wine, early made the important observation that fermentation and the production of alcoholic liquids go hand in hand. This discovery, as time passed, became common knowledge, with the result that fermented liquids from different sources came to be looked upon as characteristic national drinks—thus in France wine from grapes, in Jamaica rum from cane, in Russia vodka from rye, in Japan saki from rice, in Germany beer from barley and in America whiskey from Indian corn.

But some substances long used in the formation of alcohol, unlike the juice of grapes, are themselves unfermentable. Some of these we shall consider more in detail.

Common or cane sugar, although of itself incapable of undergoing alcoholic fermentation, by the action of a ferment invertase, takes up a molecule of water, splitting into glucose and fructose, both of which are fermentable. Thus cane sugar,, becomes (glucose) and  (fructose). From the fermentation of glucose and fructose alcohol results.

The starch of cereal grains when converted into fermentable sugar likewise becomes an effective source for alcoholic fermentation. It has long been known that a starch paste, to which malt or malt extract (containing diastase) has been added, becomes transformed into a sugar maltose. Now maltose itself is not subject to alcoholic fermentation, and so it must be acted upon by another ferment, maltase. This converts the maltose into dextrose and glucose, the latter of which we have seen to be produced in the case of cane sugar.

In 1837 Cahours employed potatoes as a source for alcoholic fermentation. The starch of potatoes is insoluble in cold water, but upon heating it in the presence of dilute sulphuric acid the starch is converted into fermentable sugar. In this process in addition to the ethyl alcohol produced a considerable amount of one of the higher alcohols, amyl alcohol, was discovered.

Two years earlier than the discovery of amyl alcohol another alcohol was obtained. This was produced not by fermentation, but by the destructive distillation of wood, and was therefore called wood or methyl alcohol.