DR. L. GALL ON IMPROVEMENTS IN WINE-MAKING. 



263 



Fior. 2. 



4. That experience has tauglit us, for more tlian ten years, in 

 all the different German grape districts, that a proportionable ad- 

 dition of water and sugar forms the means to produce, oven from 

 the most sour must, as drinkable and as good a wine as is other- 

 wise produced in good medium seasons. 



A remarkable attribute of the acid of wine lies in the fact that, 

 reduced by a great deal of water and mixed with but little alco- 

 hol, it will, in the course of time, change into acetic acid, which 

 explains the little durability of the weak wines of inferior seasons. 

 Acetic acid is not contained in rp-aj^es ; it is merely oxydized alco- 

 hol, and can only be formed after this is previously produced by 

 fermentation. 



Acid Scales and their Use. 



The first instrument of this kind, invented by Mr. 

 Otto, which, being based upon the principle that the con- 

 tents of acids are estimated as those of vinegar, proved 

 very useful, and was generally adopted. We have at this 

 day, however, another newly-invented one, in Otto's Acetic 

 Acid Scale {Fig. 2). This is composed of a glass tube, ten 

 or twelve inches long and half an inch wide, closed at the 

 bottom. This is filled with blue litmus tincture up to the 

 line a. After this, the must, previously filtered, is added 

 up to the line 0, taking care that it is not in a state of fer- 

 mentation. By the action of the acids in the must, the 

 litmus tincture, which would retain its hlue color if mixed 

 with water, turns red or rose color. Now if to this fluid a 

 solution of ammonia be added, the tube being in the mean 

 time shaken gently to promote the mixing, it will be found 

 that the red color changes to an onion-red or violet-hlue, ac- 

 cording to the greater or less quantity of the neutralizing 

 agent. This, as before stated, shows the perfect satiation 

 of the acids, and the degree line of the fluid in the tube 

 shows the contents of acids of the must by whole, half, 

 and quarter per cents, of weight. The lines 1, 2, 3 mark 

 the whole percentage, and the lesser divisions the quar- 

 ter per cent. 



This highly valuable instrument needed but a more . 

 commodious contrivance to adapt it better still to general 

 use. This has been effected by giving to it (as shown in Fig. 3, 

 on the following page) a little smaller diameter, but at the same 

 time an exactly half as large again cubic space to all its divisions. 

 By this it becomes possible to divide each per cent, into tenths 

 instead of fourths ; the whole space above 0, therefore, is divided 

 into thousandths, and gives to each /)ro onille the same space — i. e., 

 the same space from one dividing line to another — as the former 

 instrument offered for the quarter per cent, lines. The only evil 

 was, that by the turning over and shaking of the glass tube to 



