FABRICATION OF VINEGAR. 127 



An addition of phosphates to the alcoholic liquid is also said to 

 produce a favorable effect upon the augmentation of the ferment. 

 Commercial solid phosphoric acid is dissolved in water and the 

 solution neutralized with potassium, a solution of potassium phos- 

 phate being obtained in this manner. The vinegar ferment being 

 very sensitive towards this salt a very small quantity of the 

 solution, about YTOIHJ of the weight of the alcoholic fluid, may be 

 added. The experiment must, however, be made very cautiously 

 and the effect upon the working of the generator carefully noted. 



Disturbances referable to the Quantity of newly formed Acetic Acid. 



With a proper state of working the alcoholic liquid brought 

 into the generators should be completely converted into vinegar, 

 and, theoretically, the product running off show the same strength 

 as the vinegar used for acidtilation. Actually, there are, however, 

 slight variations not exceeding a few tenths of one per cent. 

 Should greater differences appear a disturbance actually exists 

 and may show itself in various ways : the generator may work 

 too feebly or too vigorously. In the first case the content of acetic 

 acid in the fluid running off decreases considerably, while that of 

 alcohol increases. The process of the formation of vinegar is, so 

 to say, only half carried through, a great portion of the alcohol 

 being converted, not into acetic acid, but into aldehyde. The 

 greater portion of this combination is lost to the manufacturer on 

 account of its low boiling point (71.6 F.), it escaping in the form 

 of vapor, the stupefying odor of which when noticed in the air 

 of the workroom is accepted by all manufacturers as indicative of 

 a disturbance in the regular working of the generators. This 

 odor, however, becomes perceptible only after the disturbance has 

 continued for some time with the loss of a considerable quantity 

 of alcohol. Hence the control of the working of the generators 

 by a frequent determination of the acid becomes necessary. Re- 

 peated observations of the thermometer also furnish valuable 

 hints about the progress of the chemical process. The temperature 

 in this case remains only for a short time unchanged and soon 

 falls, far less heat being liberated in the mere conversion of alco- 

 hol into aldehyde than when oxidation progresses to the formation 



