QUICK PROCESS OF FABRICATION OF VINEGAR. 67 



loosely and covered with a loaded lid. A steam-pipe is intro- 

 duced through a hole near the lid and the tap-hole near the 

 bottom is opened. The steam-pipe being connected with a boiler, 

 in which prevails a tension of If to 2 atmospheres, the steam- 

 cock is at first opened but slightly, to prevent the steam entering 

 with great force, from throwing off the lid, or even bursting the 

 vessel. In the commencement of the operation the steam con- 

 denses on the shavings, but after some time the vessel becomes 

 very hot, and a dark-colored fluid, consisting of almost boiling 

 water charged with extractive substances of the wood, begins to 

 run off. After continuous steaming for about 20 to 60 minutes 

 according to the size of the vessel the fluid running off be- 

 comes clearer until finally clear water is discharged, which is in- 

 dicative of the removal of the extractive substances soluble in 

 water. 



Although not absolutely necessary it is advisable to dry the 

 steamed shavings. When air-dried they still contain about 20 

 per cent, of water, which in the subsequent " acidulation" of the 

 generator must be replaced by vinegar. Hence it is recommended 

 to dry the shavings completely by exposing them for some time 

 to a current of air of 194 to 212 F. 



In a factory provided with a central heating apparatus* in the 

 cellar, this drying of the shavings can be effected without diffi- 

 culty, it only being necessary to put them in a vessel with a per- 

 forated bottom and open on top, and place the vessel over an 

 aperture of the channel through which the hot air from the heat- 

 ing apparatus ascends, closing all other apertures. 



Entirely dry wood absorbing with avidity moisture from the 

 atmosphere, the shavings thus dried should immediately be 

 brought into another vessel and, while still hot, moistened with 

 the vinegar intended for acidulation. 



Before using the shavings for filling the generators it is neces- 

 sary to allow them to swell by placing them in water or alcoholic 

 liquid. If this were omitted and the shavings introduced in a 



* The arrangement of a central heating apparatus will be described later 

 on in speaking of the arrangement of the factory. 



