DISTILLATION. 265 



inch from their insertion into the common tube. As to the 

 upper worm, since the wine which serves it as a bath may 

 become heated to a degree sufficient for producing alcoholic 

 vapor, it is necessary that the cask in which it is contained 

 should be hermetically closed, and that there should be, in 

 the top, only a socket to permit its being filled, and a tube 

 by which the alcoholic vapor may be transmitted to the bot- 

 tom of the second boiler. A large stop-cock placed lateral- 

 ly at the bottom of the cask serves for drawing off the hot 

 wine whenever the first boiler is to be filled. 



The mechanism of this apparatus is easily understood. 

 When the two boilers and the cask containing the worm are 

 filled, the liquid in the first is heated to the boiling point ; 

 the second is acted upon by the heal which escapes from the 

 fire of the first. The vapors arising from the first are trans- 

 mitted to the second, where they are condensed, and give 

 out all their heat to the body of wine into which they pass. 

 This liquid is soon raised to the boiling point, and all the va- 

 por arising from it passes into the condensing cylinder, the 

 coldness of which condenses the aqueous particles, and with 

 them a portion of alcohol. This condensed fluid is returned 

 by pipes into the bottom of the first boiler, where it is deprived 

 of its alcohol by a second distillation. That portion of va- 

 por which remains uncondensed, passes into the first worm, 

 where it is reduced to the liquid state, and this liquid upon 

 passing into the second worm is deprived of all its heat. By 

 this apparatus excellent alcohol, marking from. 36° to 38° of 

 the hydrometer, (:= specific gravity of 0.847 to 0.837,) may 

 be obtained at a single heating. 



As the purity of the alcohol is increased by the coldness 

 of the water in which the condensing cylinder is immersed, 

 it is necessary that this should be changed as ofl;en as pos* 

 sible. 



It is easily seen, that if the tube which conveys the vapor 

 from the second boiler into the condensing cylinder, trans- 

 mitted it immediately into the worm, the product would be 

 common brandy ; but as it is freed from watery particles by 

 means of the condenser, it yields a spirituous liquor of the 

 higher degrees. 



If, instead of filling the first boiler with wine, it be filled 

 with water, and the second with mash of grapes or with fer- 

 mented grain, the operation may be conducted in the same, 

 manner, and alcohol extracted without any hazard of burn- 

 ing the boiler. 



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