248 VINEGAR, CIDER, AND FRUIT-WINES, 



with a boiling point above 212 F. are gradually formed from the 



acetone.) 



After several hours' digestion the mixture is distilled by means 

 of steam. In Fig. 60, a represents the copper still, b an ellipsoidal 



Fig. 60. 



or egg-shaped vessel which serves as a receiver, and c the rectify- 

 ing apparatus, consisting of a series of Pistorius's basins (see Fig. 

 57, p. 238), into the uppermost of which a moderate current of 

 water is conducted ; d is the condenser. 



The still a has a capacity of 1000 to 1200 quarts ; the steam 

 pipe placed in it is 2 inches in diameter and 32 feet long. The 

 vapors pass out through the wide pipe in the cover, and what is 

 condensed in b runs back through a narrower pipe into a. In 

 the rectifying vessel or rather dephlegmator, the rising vapors are 

 forced to pass around a copper disk placed in each basin and thus 

 to come in contact with the surface of the basin cooled by water. 

 From this it is evident that the less volatile bodies are condensed 

 in the basins and run back into b and from there into a, while 

 the more volatile vapors pass through the swan-neck and are con- 

 densed in d. Much, of course, depends on the quantity (and 

 temperature) of the water running into the rectifying vessel. 



With a rectifying vessel consisting of seven basins, each 1.64 



