ALCOHOL 43 



When the characters of ordinary alcohol have been stated, allusion will bo made to 

 the class of bodies of which this is the type. 



Fermented liquors were known in the most remote ages of antiquity. We read 

 (Genesis ix.) that after the flood ' Noah planted a vineyard, and he drank of the 

 wine and was drunken.' . Homer, who certainly lived 900 years before the Christian 

 era, also frequently mentions wine, and notices its effects on the body and mind 

 (Odyssey IX. and XXI.); and Herodotus tolls us that the Egyptians drank a 

 liquor fermented from barley. The period when fermented liquors were submitted 

 to distillation, so as to obtain 'ardent spirits,' is shrouded in much obscurity. 

 Eaymond Lully ' was acquainted with ' spirits of wine,' which he called aqua 

 ardcns. The separation of absolute alcohol would appear to have been first 

 effected about this period (1300), by Arnauld de Villeneuve, a celebrated physician 

 residing in Montpellier (Gerhardf), and its analysis was first performed by 

 Th. de Saussure. 2 



The preparation of alcohol may be divided into three stages : 



1. The production of a fermented vinous liquor the Fermentation. 



2. The preparation from this of an ardent spirit the Distillation. 



3. The separation from this ardent spirit of the last traces of water the 



Beatification. 



1. Fermentation. The term 'fermentation' is now applied to those mysterious 

 changes which vegetable (and animal) substances undergo when exposed, at a certain 

 temperature, to contact with organic or even organised bodies in a state of change. 



There are several bodies which suffer these metamorphoses, and under the influence 

 of a groat number of different exciting substances, which are termed the ' ferments ; ' 

 moreover, the resulting products depend greatly upon the temperature at which the 

 change takes place. 



The earliest known and best studied of these processes is the one commonly 

 recognised as the vinous or alcoholic fermentation. 



In this process solutions containing sugar either the juice of the grape (see 

 WINE) or an infusion of germinated barley, malt (see BEER) are mixed with a 

 suitable quantity of a ferment ; beer or wine yeast is usually employed (see YEAST), 

 and the whole maintained at a temperature of between 70 and 80 F. (21 to 

 26 C.) 



Other bodies in a state of putrefactive decomposition will effect the same result as 

 the yeast, such as putrid blood, white of egg, &c. 



The liquid swells up, a considerable quantity of froth collects on the surface, and 

 an abundance of gas is disengaged, which is ordinary carbonic acid (CO 2 ). The 

 composition of (pure) alcohol is expressed by the formula C 1 H 6 O 2 (C 2 H 6 O), and it 

 is produced in this process by the breaking up of grape sugar, C 12 H 12 O 12 . 2 HO 

 (C 6 H 12 O 8 . H 2 O) into alcohol, carbonic acid, and water, thus : 



C 12 H 12 O 12 . 2H = 2C< H 8 O 2 + 4C O 2 + 2H 



grape-sugar. alcohol. carbonic acid. 



C* H 12 O 6 . H 2 O =-- 2C- H 6 O + 2C O- + 



It is invariably the grape sugar which undergoes this change ; if the solution con- 

 tains cane sugar, the cano sugar is first converted into grape sugar under the influenca 

 of the ferment. See SUGAE. 



Much diversity of opinion exists with respect to the office which the ferment per- 

 forms in this process, since it does not itself yield any of the products. See FER- 

 MENTATION. 



The liquid obtained by the vinous fermentation has received different names, 

 according to the source whence the saccharine solution was derived. When pro- 

 cured from the expressed juice of fruits such as grapes, currants, gooseberries, 

 &c. the product is denominated wine ; from a decoction of malt, ale or beer ; from 

 a mixture of honey and water, mead ; from apples, cider ; from the leaves and small 

 branches of spruce-fir (Abies excelsa, &c.), together with sugar or treacle, spruce; 

 from rice, rice beer (which yields the spirit arrack'); from cocoa-nut juice, palm 

 wine. 



It is an interesting fact that alcohol is produced in very considerable quantities (in 

 the aggregate) during the raising of bread. The carbonic acid which is generated in 

 the dough, and which during its expulsion raises the bread, is one of the products of 

 tho fermentation of the sugar in t^lio flour, under the influence of the yeast added ; 

 and of course at the same time the complementary product, alcohol, is generated. As 



' Thomson's History of Chemistry, i. 41. (1830). Annales do Chlmic, xlli. 225. 



