354 PREPARATION OF ALCOHOLIC DRINKS. 



TThe action of alcohol in lowering the temperature, even in moderate doses, is most import- 

 ant By dilating the cutaneous vessels, it thus permits of the radiating of much heat from 

 the blood When the action of alcohol is pushed too far, and especially when this is combined 

 with the action of great cold, its use is to be condemned. Brunton has pointed out that, as 

 regards its action on the nervous system, it seems to induce progressive paralysis, affecting the 

 nervous tissues "in the inverse order of their development, the highest centres being affected 

 first and the lowest last." The judgment is affected first, although the imagination and 

 "emotions may be more than unusually active." The motor centres and speech are affected 

 then the cerebellum is influenced, and afterwards the cord, while by and by the centres essential 

 to life are paralysed, provided the dose be sufficiently large.] 



Preparation. Alcoholic drinks are prepared by the fermentation of various carbohydrates, 

 such as sugar derived from starch. The alcoholic fermentation, such as occurs m the manu- 

 facture of beer, is caused by the development of the yeast plant, Saccharomycetes cerevisire ; 

 while in the fermentation of the grape (wine), S. Ellipsoideus is the species present (ng. 237). 

 The yeast takes the substances necessary for the maintenance of its organic processes directly 

 from the mixture of the sugar, viz., carbohydrates, proteids, and salts, especially calcium and 

 potassium phosphates and magnesium sulphate. These substances undergo decomposition 

 11 m within the cells of the yeast 



^s. /'-x III plant, which multiply dur- 



& ^L. *m>&Q f(&w\ ^J-UtA r\ * n 8 tne P rocess anc ^ there 



&* v ' ^* ) fe ^*\p Wt J I $agk \ 0m are produced alcohol and 



./' ^ \@/ vST/ JfQ C0 2 ( 15 )> together with 



'''' xL/ V_y *w| glycerine (3*2 to 3 '6 per 



Jf cent. ) and succinic acid (0 6 



p. 2 7 to 07 per cent.). Yeast is 



, ... . _ . ,. , either added intentionally 



1, Isolated yeast cells; 2, 3, yeast cells budding; 4, 5, so-called or it reaches the m i xtU re 



endogenous formation of cells ; 6, sprouting and formation of buds. f rom tne a j^ w hj c j, always 



contains its spores. When yeast is completely excluded, or if it be killed by boiling [or if its 



action be prevented by the presence of some germicide], the fermentation does not occur. The 



alcoholic fermentation is due to the vital activity of a low organism. 



In the preparation of brandy, the starch of the grain or potatoes is first changed into sugar 

 by the action of diastase or maltin. Yeast is added, and fermentation thereby produced ; the 

 mixture is distilled at 78*3 C. The fusel oil is prevented from mixing with the alcohol by pass- 

 ing the vapour through heated charcoal. The distillate contains 50 to 55 per cent, of alcohol. 



In the preparation of wine, the saccharine juice of the grape the must after being expressed 

 from the grapes, is exposed to the air at 10 to 15" C, and the yeast cells, which are floating 

 about, drop into it and excite fermentation, which lasts 10 to 14 days, when the yeast sinks to 

 the bottom. The clear wine is drawn off into casks, where it becomes turbid by undergoing an 

 after-fermentation, until the sugar is converted into alcohol and C0 2 , which is accompanied by 

 the deposition of some yeast and tartar. If all the sugar is not decomposed which occurs 

 when there is not sufficient nitrogenous matter present to nourish the yeast a sweet toine is 

 obtained. Wine contains 89 to 90 per cent, water, 7 to 8 per cent, alcohol, together with 

 athylic, propylic, and butylic alcohol. The red colour of some wines is due to the colouring 

 matter of the skin of the grapes, but if the skins be removed before fermentation, red grapes 

 yield white wine. When wine is stored, it develops a fine flavour or bouquet. The characteristic 

 vinous odour is due to oenanthic ether. The salts of wine closely resemble the salts of the 

 blood. 



In the preparation of beer the grain is moistened, and allowed to germinate, when the 

 temperature rises, and the starch (68 per cent, in barley) is changed into sugar. Thus "malt" 

 is formed, which is dried, and afterwards pulverised, and extracted with water at 70 to 75, 

 the watery extract being the "wort." Hops are added to wort, and the whole is evaporated, 

 when the proteids are coagulated. Hops give beer its bitter taste, and make it keep, while their 

 tannic acia precipitates any starch that may be present, and clarities the wort. After being 

 boiled, it is cooled rapidly (12 C.) ; yeast is added, and fermentation goes on rapidly and with 

 considerable effervescence at 10 to 14. Beer contains 75 to 95 per cent, water ; alcohol, 2 to 

 5 per cent, (porter and ale, to 8 per cent.) ; CO.,, 0*1 to 0*8 per cent. ; sugar, 2 to 8 per cent. ; 

 gum, dextrin, 2 to 10 per cent. ; the hops yield traces of protein, fat, lactic acid, ammonia 

 compounds, the salts of the grain and of the hops. In the ash there is a great preponderance 

 of phosphoric acid and potash, both of which are of great importance for the formation of blood. 

 In 100 parts of ash there are 40*8 potash, 20 '0 phosphorus, magnesium phosphate 20, calcium 

 phosphate 2 '6, silica 16*6 per cent. The formation of blood, muscle, and other tissues from 

 the consumption of beer is due to the phosphoric acid and potash, while if too much be taken, 

 the potash produces fatigue. 



Condiments are taken with food, partly on account of their taste, and partly 

 because they excite secretion. Common salt, in a certain sense, is a condiment. 



