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and are similar to Spanish wines in their flavour, 
but they possess no bouquet. The grapes grown 
at the Cape from Riesslings, transplanted from 
the Rhine, produce an excellent wine, which does 
not, however, possess the aroma peculiar to the 
Rhenish wine. It is evident, from these facts, 
that the acid of wines, and their characteristic 
perfumes, have some connexion, for they are al- 
ways found together; and it can scarcely be 
doubted that the presence of the former exercises 
a certain influence on the formation of the latter. 
It is only in liquids containing other very soluble 
acids, that the fatty acids and cenanthic acid 
are capable of entering into combination with 
the ether of alcohol, and of thus producing com- 
pounds of a peculiar smell. This ether is found 
in all wines containing a free acid, but is absent 
from those in which no acids are present. This 
acid, therefore, is the means by which the smell 
is produced ; since without its presence cenanthic | 
ether could not be formed. On the Rhine, also, 
an artificial bouquet is often given to wine for 
fraudulent purposes, by the addition of several 
species of the sage and rue to the fermenting 
liquor; but the fictitious perfume thus obtained 
differs from the genuine aroma, by its inferior | 
durability, and by being gradually dissipated. 
The juice of grapes grown in different climates 
differs not only in its proportion of free acid, but 
_-also in respect of the quantity of sugar dissolved 
| init. 
| juice seems to be the same in whatever part the 
a 
(eh rp ae 
The quantity of azotised matter in the 
grapes may grow; at least, no difference has been 
observed in the amount of yeast formed during 
| fermentation in the south of France, and on the 
Rhine. The grapes grown in hot climates, as 
well as the boiled juice obtained from them, are 
proportionally rich in sugar. Hence, during the 
fermentation of the juice the complete decompo- 
sition of its azotised matters, and their separation 
in the insoluble state, are effected before all the 
sugar has been converted into alcohol and car- 
bonic acid. A certain quantity of the sugar 
consequently remains mixed with the wine in an 
undecomposed state, the condition necessary for 
its further decomposition being absent. The 
azotised matters in the juice of grapes of the 
temperate zones, on the contrary, are not com- 
pletely separated in the insoluble state, when the 
entire transformation of the sugar is effected. 
The wine of these grapes, therefore, does not con- 
tain sugar, but variable quantities of undecom- 
posed gluten in solution. This gluten gives the 
wine the property of becoming spontaneously 
converted into vinegar, when the access of air is 
not prevented; for it absorbs oxygen and be- 
comes insoluble, and its oxidation 1s communi- 
cated to the alcohol, which is converted into 
acetic acid. By allowing the wine to remain at 
rest in casks with a very limited access of air, and 
at the lowest possible temperature, the oxidation 
of this azotised matter is effected without the al- 
cohol undergoing the same change, a higher tem- 
perature being necessary to enable alcohol to 
combine with oxygen. As long as the wine in 
‘the stilling-casks’ deposits yeast, it can still be 
caused to ferment by the addition of sugar; but 
old well-cleared wine has lost this property, be- 
cause the condition necessary for fermentation, 
namely, a substance in the act of decomposition 
or putrefaction, is no longer present init. Inhotels 
and other places where wine containing much glu- 
ten is drawn gradually from a cask, and a propor- 
tional quantity of air necessarily introduced, its 
eremacausis, that is, its conversion into acetic 
acid, is prevented by the addition of a small quan- 
tity of sulphurous acid. This acid, by entering 
into combination with the oxygen of the air con- 
tained in the cask, or dissolved in the wine, pre- 
vents the oxidation of the organic matter.” 
Many of the wines of commerce contain ingre- 
dients or principles altogether foreign to their 
proper nature,—added to them for the purpose 
of adulteration, of concealing their bad proper- 
ties, or of improving their odour or colour or 
taste. Such flavouring substances as orris root, 
bitter almonds, nitrous ether, oak chips, worm- 
wood, and white leather are very extensively 
used for white wines; such colouring substances 
as common red and brown dye-stuffs, logwood, 
Brazil wood, elder berry, and iron are profusely 
used for red wines; such poisonous substances as 
litharge and white lead are not unfrequently used 
for correcting the acidity of wines which have 
become sour; and such terribly murderous sub- 
stances as arsenic and corrosive sublimate have | 
sometimes been used in the process of fining. 
Liquid potash precipitates the natural principles 
of wine green, and therefore serves as a good test 
for promptly ascertaining whether any specimen 
of the wines of commerce be an artificial mixture ; 
and a few drops of the prussiate of potash throw 
down a whitish precipitate in any specimen.which 
contains a salt of lead, and therefore readily de- 
tect the presence of litharge or white lead. 
The Manufacture of Wines.—When the grapes 
are ripe, and have attained their sweetest or most 
saccharine state, the juice, then called the must, 
is pressed out of them, and put into suitable ves- 
sels for undergoing fermentation. “ When the 
must is exposed to the temperature of 65° of 
Fahrenheit’s scale,” says Dr. Henderson, in his 
History of Ancient and Modern Wines, “it speed- 
ily begins to ferment. Small bubbles first collect 
on the top, and may be seen gradually issuing 
from the central parts of the liquor, and bringing 
up the husks, stones, and other grosser matters 
which it contains. As the disengagement of gas 
proceeds, a hissing noise is produced by the burst- 
ing of the bubbles; and a frothy crust or scum is 
formed by the viscid particles which they have 
carried to the surface. An increase of the tem- 
perature and bulk of the fermenting mass now 
takes place; the must loses its original consis- 
tency and its saccharine taste, acquiring a deeper 
colour and a vinous flavour, with an odour of 
SS Se 
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