On the Analyjis of Wine. 133 



aperture is terminated by a neck fonie inches in length, in 

 which is adapted a fniall cover called the head, which in- 

 creafes in diameter towards the upper part lo as to have the 

 fonn of a truncated cone inverted. From the angle of the 

 bafc of this capital proceeds a fmall tube defiined to receive 

 the vapour of the ipirit, and to tranfipit it to the worm with 

 which it is connefted. The worm confifts of fix or feven 

 circumvolutions, and is placed in a cafk kept full of wafer to 

 facilitate the condenfation of the vapours: liiefe vapours, 

 when condenfed, run down into a tub dellined to receive 

 them. 



The boilers, in general, are fixed in mafon-work up to the 

 part where the contraftion takes place: the bottom alone is 

 expofed to the inmiediate aftion of the heat. The chmmey 

 is placed oppofite to the fire-hole; and the afli-holc, which, 

 is not very large, is feparated from the fire-place by an iron 

 grate. 



The boiler is charged with five or fix quintals of w iue. The 

 diftillation is completed in eight or nine hours, and during 

 each operation about fixtv pounds of coals areconlumed. 



Such is the procefs which has been long ufed in Langue- 

 doc ; but though old, and generally adopted, it prefents im- 

 perfcclions, which muft (irike every man acquainted with 

 the principles of diftillation, 



I ft. The form of the boiler produces a column of liquor 

 exceedingly high and not broad, which being expofed to the 

 adVion of the heat only bv its bafe, is burnt in that part be- 

 fore the upper part becomes warm ; bubbles then rife from 

 the bottom, which, beino- oblig-ed to traverfe a colder mafs 

 of licpiid, are condenfed, and again diflblve in the liquor. 

 It is only when the whole mafs has been heated gradually 

 that the diftillation is eftablifiied. 



2d, The coulrailion at the upper part of the boiler and 

 the internal bendimj: which it prclents in that place, ftill hurt 

 the dili illation : for this part, not being covered by mafon- 

 work, is continually expofed to the an-, which maintains 

 there a colder temperature than in other parts, fo that the 

 vapours which rile are condenfed partly againlt the interior 

 furface, and fall down in drops, or run back in flriiB into 

 the body of the ftill. In this cafe, the fame thing happens 

 which we daily fee take place in diftilling with a fand bath : 

 the vapours which rife, firiking againft the uncovered iurfiice 

 of the retort, which is always the coldefl:, are condf.n'ed, and 

 fall down in ftriae into the bottom ; fo that the fame portion 

 of matter rifes, falls down, and is diftillcd fevcral times; 

 which occaiions lofs of time, cxpcnle in fuel, and hurls tho 



I 3 (juality 



