PREPARATION OF THE ALCOHOLIC LIQUID. 113 



taste from the admixture of salts should not be used under any 

 circumstances. 



Many well-waters are very hard, i. e., they contain a compara- 

 tively large quantity of calcium carbonate in solution. If such 

 water be used in the preparation of alcoholic liquid, the calcium 

 carbonate is decomposed by the acetic acid and the vinegar con- 

 tains a corresponding quantity of calcium acetate in solution. 

 Other well-waters contain a large quantity of gypsum (calcium 

 sulphate) in solution ; which salt is not changed by acetic acid, but 

 remains partially dissolved in the finished vinegar. 



When water very rich in gypsum is mixed with alcohol the 

 fluid at first entirely clear becomes in a short time opalescent and 

 finally perceptibly turbid. After long standing a very delicate 

 white sediment separates on the bottom of the vessel, the fluid 

 becoming again clear. This phenomenon is explained by the fact 

 that gypsum while soluble in water with comparative ease is next 

 to insoluble in a fluid containing alcohol, and hence gradually 

 separates in the form of minute crystals. 



Water containing no gypsum but much calcium carbonate 

 shows after mixing with spirits of wine a similar behavior ; it at 

 first becomes turbid and again clear after separating a delicate 

 white precipitate. Calcium carbonate is soluble only in water 

 containing a corresponding quantity of carbonic acid ; on standing 

 in the air the carbonic acid escapes and the calcium carbonate 

 separates. 



This behavior of w r ater when mixed with alcohol and standing 

 in the air can be utilized for the almost complete separation of 

 the gypsum and calcium carbonate. Mixtures of water and alco- 

 hol, in the proportion the alcoholic liquids are to have, are first 

 prepared and the fluid stored in barrels in a warm apartment 

 near the workroom. The mixtures at first turbid become clear 

 after some time and are then drawn off from the sediment by 

 means of a rubber hose. A comparative examination of the 

 water and the mixtures shows that the latter contain only very 

 small quantities of gypsum and calcium carbonate in solution. 



River water, though generally soft, i. e., poor in the above-men- 

 tioned salts, is seldom sufficiently clear to be used without previous 

 filtration. It is further very likely that the small worms, known 

 8 



