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VINEGAR, CIDER, AND FRUIT-WINES. 



only used as fuel. This evil could be overcome by providing a 

 discharge aperture for the heavier vapors on the lower half of 

 the retort ; but this has again the disadvantage that the exchange 

 of the hot vessels cannot be effected as rapidly. 



In England and Germany horizontal retorts, which are uni- 

 formly surrounded by the flame, are in general use. To prevent 

 a disadvantage similar to the one mentioned above, the retorts, 

 however, must not be too long, as the vapors from the front have 

 to pass over the glowing back portion to reach the discharge 

 aperture. 



Vertical retorts. Fig. 49 shows Kestner's apparatus, which is in 

 extensive use in France. The retort a has a capacity of 3 cubic me- 

 ters (105.94 cubic feet). It is surrounded by flues which lead to the 

 chimney t. Large sticks are set upright in the retorts ; those too 

 thick should be split, and small wood packed close. The retort 

 is closed at the top by an iron cover secured by screws or clamps. 



Fig. 49. 



The products of distillation are condensed in the copper pipes b, 

 which are inclosed in wider cast-iron or copper pipes d. In the 

 latter a current of water passes from e through the connecting pipe 

 / from below to above, and effects the cooling off of the vapors. 

 The non-condensed vapors and gases are conducted through c 



