WORK IX A VINEGAR FACTORY. 119 



If a generator works up the quantity of alcoholic liquid in- 

 tended for 12 or 15 hours in 10 or 12 hours, it is more proper, 

 on account of the diminished loss by evaporation, to induce slower 

 work by decreasing the draught of air in order to maintain the 

 rule that a generator has to work up 3 liters (3.16 quarts) of 

 absolute alcohol in the working time of a day. 



After controlling for several days the work of a generator, by 

 examining the products as to their contents of acetic acid and 

 alcohol, the plan of operation resolves itself from the results of 

 these tests, since it is then accurately known after how many 

 pourings of an alcoholic liquid of known composition an addition 

 of alcohol is required ; further, after how many pourings a finished 

 product is present, so that directions for the progress of the opera- 

 tion can be given to the workmen according to time and quantities. 

 The normal working of the generators can always be controlled 

 by from time to time repeating the test of the products. 



Now, suppose the work in a newly arranged factory, having 

 reached the point at which acidulation is complete, the actual 

 fabrication, according to the old method, will be gradually com- 

 menced by pouring in alcoholic liquid of corresponding concen- 

 tration. 



The shavings in the generator having been saturated with 

 acidulating vinegar, the latter is partially replaced by the fluid 

 poured in, and as much as is expelled runs off. If the generator 

 should at once commence to work regularly the temperature in 

 its interior would be observed to rise, though it would at first be 

 impossible to establish a change in the composition of the fluid 

 running off. Slight variations in the content of acetic acid and 

 a small percentage of alcohol could be determined in the fluid 

 only after the acidulating vinegar originally present has been 

 entirely expelled by a series of pourings. 



With the progress in the fabrication of vinegar, it became 

 customary to produce the strongest vinegar possible, the so-called 

 triple vinegar, with about 12 per cent, of acetic acid. On account 

 of its greater commercial value, this article could be sent great 

 distances, the consumer reducing it to a weaker product by the 

 addition of water. 



To prepare directly vinegar with such a high percentage of 



