49 Dujardin's roll press 155 50 Defusion battery 158 51 Mixing vat 165 52 Syke's hydrometer 176 53 Field's alcoholometer 182 54 Geisler's apparatus 184 55 Continuous grain alcohol distillery--Barbet's system 198 56 Grain distillery, capacity 2500 bushels per day _to face_ 198 57 Small beet distillery 200 58 Large beet distillery 202 59 Molasses distillery, capacity 2500 gallons per day _to face_ 206 60 Molasses fermenting house 207 CHAPTER I. ALCOHOL, ITS VARIOUS FORMS AND SOURCES. =Alcohol.= (Fr., _alcool_; Ger., _alkohol_.) Formula, C_{2}H_{6}O. Pure alcohol is a liquid substance, composed of carbon, hydrogen, and oxygen, in the following proportions: C 52.17 H 13.04 O 34.79 ------ 100.00 It is the most important member of an important series of organic compounds, all of which resemble each other closely, and possess many analogous properties. They are classed by the chemist under the generic title of "Alcohols." Alcohol does not occur in nature; it is the product of the decomposition of sugar, or, more properly, of _glucose_, which, under the influence of certain organic, nitrogenous substances, called _ferments_ is split up into alcohol and carbonic anhydride. The latter is evolved in the form of gas, alcohol remaining behind mixed with water, from which it is separated by distillation. The necessary purification is effected in a variety of ways. TABLE I.--THE BOILING POINTS OF ALCOHOLIC LIQUORS OF DIFFERENT STRENGTHS, AND THE PROPORTIONS OF ALCOHOL IN THE VAPORS GIVEN OFF.