A L C 



A L C 



in which its chemical properties are the moft confpicu- 



OUS. 



Alcohol, as wlU as anient fpirits of difTcrent kinds, is 

 procured mo'l largely in this countr)- from a fermented grain- 

 liqiior, prepared tor the exprefs purpofe of diliillation, from 

 praiu, inela(res, &c. ; but in the wine coinilries, the I'pirit 

 i% obtained troni the dilHUation of wine ; wlicnce tlie fyno- 

 nimons term, Jpirit of luinc. We flnvll only take the exam- 

 ple of brandy, wliich i;^ the prod\id of tin fnll dillillation 

 of wine, and mention the method by which alcohol is pro- 

 cured from it by reftification. 



Brandy is a compound of alcohol, water, a colom'ing 

 extraflive matter, and a fmall quantity of oil. It is to the 

 two lall that it owes its peculiar flavour, fmell, and appearance, 

 whereby it is dilHnguifhed from other diltiiled fpirits. The 

 objeft of the procefs of reftification is to feparate the fn-(l 

 from the other ingredients, and this feparation is cffefted upon 

 the principle that alcohol is the mod eafily volatilized when 

 agentle heat is applied, and therefore appears in tiie firft pro- 

 duifl of dillillation, whilll the extraftive matter and much 

 of the water remain behind. It is more difficult, however, 

 to get rid of the fmall portion of oil which brandy con- 

 tains, as tliis is foluble in alcohol, and will nfe with it in 

 dillillation, unlefs prevented by the means which will be pre- 

 fenth mentioned. 



Tiie obfenations of M. Baume, and hisdireftions for the 

 preparation of alcohol, are fo judicious and accurate that we 

 fhall here mention them. 



Tin- following is the procefs given by this able chemift : 

 " To procure reirlificd alcohol, put a quantity of brandy in 

 the water bath of an alembic, and proceed to dillillation. 

 Set apart the firll product of the dillillation wlien it amoimts 

 to about a fourth part of the liquor put into the alembic. 

 Then continue the procefs till about as much more is ob- 

 tained, or till the liquor comes over white ajid milky. Then 

 re-diilil the latter produft, and mix the firfl half which 

 comes over with the firft part of the former dillillation, and 

 continue to dillil as long as any fpirit comes over. This 

 latter portion may be again diltiiled, and the firft produft 

 mixed with the former firll: produfts, as before. After each 

 dillillation, there remains in the alembic a watery liquor 

 which retains the fmell of brandy, but is entirely deprived 

 of inflammable fpirit, and is thrown away as ufelefs. 



" Having thus procured all the fpirit from the brandy, 

 return all the referved firll produdls to the alembic, and dif- 

 till with a gentle fire. When about half the liquor has come 

 over, it fhould be kept apart as pure rectified alcohol ; the 

 remainder is to be diililled as long as it is inflammable, and 

 may either be again reftified, or refen'ed for thofe puipofes 

 where a fpirit of inferior ftrength is required." 



The reafon given by this judicious chemift for the above 

 procefs is this : the fpirit which firll paflcs over in diftilla- 

 tion is the pureft, and contains the leail portion of grofs 

 elTential oil ; the latter portion, on the other hand, is almoft 

 faturated with this oil, and the difference between the two is 

 eafily diilinguifhable when rubbed on the hands; the firll 

 produft leaves no fmell of brandy, but the lafl gives an 

 odour like the breath of drunkards, who digell their food 

 imperfcclly. The quantity of oil, however, varies accord- 

 ing to the nature of the brandy ; that which is made from 

 wine alone containing the leafl oil, but that which is pro- 

 cured from wine lees being fo full of it as to leave a flratum 

 of the oil fwimming on the watery extraftive liquor left in 

 the alembic, after all the fpirit has been diftilled off. 



M. Dubuiffon remarks concerning this oil, that the 

 J-ajiguedoc brandies contain much more of it than the 

 Cogniac ; and that after diftilling a large quantity of the for- 



mer, the head of the alembic was covered widi expanded 

 drops of the oil, which adhered to the velTel. When col- 

 ledled together, and quite cold, they became as ftiff as fuct, 

 had a chefnut colour, a llrong djfagreeablc talle, and a fmell 

 like turj>entlnc. 



Various additions have llkewife been made to the impure 

 fpirit, in order to ainft m the feparation of this oil. The 

 fimplell, and one of the moll efficacious is water. Tl>i«, 

 when added to the oily fpirit, turn:; it milky (a- is the cafe 

 with any other folution of elTential oil in alcohol), and by 

 weakening tlie adhcfion between (lie oil and the fpirit, it 

 enables the latter to rife in dillillation, unmixed with thr 

 fomier. The chief inconvenience of this addition is, that 

 it weakens the llrength of the fpirit fo much as to require 

 fucceflive redlifications before it can be fufficicntly deprived 

 of its watery part. 



Chalk, crumb of bread, bran, and other fubflancee, are 

 alfo added before dillillation to the fpirit, when oily and ill 

 flavoured ; and they all have a good eflecl in keeping down 

 the matters which contaminate the alcohol, and render the 

 dillillation more cfTeftual in purifying it. 



Q^uicklime is Hill more efficacious, but it much lefTcns the 

 produft of alcojiol, alters its nature in fome ccgrtc, and 

 makes it more penetrating. It would appear, liowever, 

 that there are fome kinds of wine in wliich the odorant par- 

 ticles are fo intimately mixed with the lpirituo\i3 part, that 

 it is fcarcely poflible to feparate thtm bv fimple dillillation, 

 however cautioufly and fliilfully conducted. 



The common Hill with the worm-tube and refrigeratory, 

 is very well calculated for the rectification of fpirits, only 

 allowance mnfl be made for the readintls with, which ardent 

 fpirit, when heated, affumes the Hate of vaponr, ur.d the 

 very great expanfion which it then undergoes. 



Alcohol, freed from all foreign ingredients but water, 

 and already of confiderable llrength, may be brought to the 

 fpecific gravity of 0.825, "' '^'-' temperature of 60'^, by a 

 fingle dillillation, where tlie heat is moderate and applied 

 very gradually, and the condenfation flow. When about a 

 third or half of the fpirit is difliUed over, the llrength 

 of the fucceeding portion is dimiiiiflied, the fpecific gravity in- 

 creafes, and it becomes more watery, and therefore the firft 

 produft fhould be kept apart. This cannot be rendeird 

 ftronger by any repetition of fimple dillillation, but it may 

 be Hill further dephlegmatcd by means which will be men- 

 tioned hereafter. 



We fhall now proceed to the properties of alcohol. 



Alcohol is a colourlefs tranlparent liquor, appearing to 

 the eye like pure water. It poflcU'es a peculiar penetrating 

 fmell, diftinft from tlie proper od(nir of the diililled fpirit 

 from which it has been procured. To tlie talle it is cxcef- 

 fively hot and burning, but without any peculiar flavour. 

 From its great liglitnefs and mobility, the bubbles v.hieh 

 are foitned on fliaking it fubfide almoil inftaotaneoufly, and 

 this is one metliod of judging of its purity. Alcohol is 

 very eafily volatilized by the heat of the hand, it even begins 

 to be converted into a very cxpanlible vapour at the tempe- 

 rature of 55° Fahr; and the quicknefs of evaporation always 

 produces a confiderable cold. It boll« at about 165°, and 

 the vapours when condenfed return unaltered to their fonner 

 Hate. It has never been frozen by any cold, natural or arti- 

 ficial, and hence its ufc in ihernionieters to meafwe vei^ low 

 temperatures. 



Alcohol takes fire vcrj- readily on the application of any 

 lighted body, the fpeedicr in proportion to its purity. It 

 bums with a pale flame, white in the centre and blue at the 

 edges ; this gives but a fmall degree of heat, and is fo faint 

 as to be kurcrly vijible in bright day-light. It bums with- 



4 C 2 «\lt 



