FABRICATION OF VINEGAR. 



135 



all the draught-holes, is left to itself for 6 to 8 hours after closing 

 all the draught-holes. The ferment in a short time consumes all 

 the free oxygen in the generators and the vinegar eels die from 

 want of it. By opening the draught-holes and pouring in alco- 

 holic liquid the normal formation of vinegar soon recommences. 



The killing of a large number of vinegar eels in the above 

 manner is, however, of considerable danger to the regular work- 

 ing of the factory, and the respective generators must be watched 

 with special care in order to meet at once any appearance of 

 putrefaction. It may sometimes succeed to keep up the work 

 undisturbed, the killed vinegar eels being gradually removed 

 from the generators by the vinegar running off. In such criti- 

 cal cases, when the generator may at any moment commence to 

 work irregularly, the use of a very small quantity of salicylic 

 acid as an addition to the alcoholic liquid would be advisable. 

 The acid by checking putrefaction would prevent the immediate 

 decomposition of the killed vinegar eels still present in the 

 generators. 



Should, however, signs of putrefaction appear energetic, means 

 should at once be taken to arrest its progress, it being in this case 



Fig. ;33. 



Apparatus for the Development of Sulphurous Acid. 



best to sulphur the generator. This is effected by closing all the 

 draught-holes except one, and introducing into the latter the 

 nozzle of the apparatus whose arrangement is shown in Fig. 33. 

 In a large clay vessel, best glazed inside, stands upon a tripod 



