Page:Popular Science Monthly Volume 70.djvu/251

Rh the same time safeguarding the revenues, resulted in this ingenious scheme of 'denaturing.' We are fifteen or twenty years behind Germany, France and practically all other civilized countries with our recent measure. It is very evident, then, that there is nothing new about denatured alcohol. Our tardiness brings one advantage, however; we may profit by the experience of others. Some of this experience and some of the more important known facts may be considered conveniently under the three heads: the manufacture of alcohol; denaturants; and uses of denatured alcohol.

The fact that alcohol results from the fermentation of sugar by means of yeast is well known. Cane or beet sugar, the chemical name for which is sucrose, is first broken up into a mixture of glucose and fructose. This mixture is known as invert-sugar, referring to optical properties which it would take too long to describe. This 'inversion' is produced by a substance called invertase present in the yeast. It may also be accomplished by the action of dilute acids. The glucose and fructose then undergo fermentation, a splitting up into ethyl alcohol and carbon dioxide, as a result of the growth of the yeast plant. Pasteur's long and brilliant investigations led him to believe that fermentation could never occur except when accompanying some kind of multiplication of cells, either yeast cells or bacteria, i. e., some form of living protoplasm, and that it was thus a physiological phenomenon. By means of great pressures, Buchner, however, succeeded in extracting from yeast a liquid which contained no cells and no living protoplasm and yet produced fermentation. The German name for this liquid is Presssaft, which may be translated into 'press-fluid.' The fermentation is produced by a substance, which Buchner called zymase, in solution in this 'press-fluid.' Since then numerous other similar substances have been discovered which produce chemical changes, formerly supposed to occur only in conjunction with life processes. These substances, the inorganic or 'cell-less' ferments, of which invertase and zymase are typical, are known as enzymes. We really know very little about these enzymes or how they work, but they are intensely interesting and many of the ablest scientists of the times are engaged in their study.

Glucose and fructose are but two of a large number of chemically similar bodies which can be obtained from a great variety of agricultural products such as corn, rye, grains of all kinds, apples, grapes and fruits of all kinds, from Irish potatoes and from sweet potatoes, in short, from anything containing either starch or sugar. A list of