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POPULAR SCIENCE REVIEW. 
acid, being in fact the first stage in the conversion of alcohol 
into vinegar.* 
All this proves that Greek wines are either extremely liable 
to a slight acetous fermentation, which, as they often contain 
much albuminoid substance, is not unlikely, or that owing to 
bad management the must or new wine is improperly exposed 
to the ordinary action of the air. The wines leave a rather high 
proportion of ash, generally rich in sulphates, which, taken in 
conjunction with the small amount of tartaric acid they contain, 
indicates that most likely plaster of Paris is used in their pre- 
paration. Lastly, Greek wines, in spite of the high proportion 
of volatile acid present, frequently contain more fixed than 
volatile ethers, contrary to what was found to be the case with 
pure natural wines, and resembling in this respect fortified 
wines generally. 
Taken as natural wines they will bear no comparison with 
the three previously considered, either as regards soundness, 
and consequent wholesomeness, or in regard to the perfection 
of their flavour and bouquet; whilst as strong wines they are 
greatly inferior to those next to be considered. 
Sherry . — This name (corrupted from Xeres) was originally 
restricted to the wine produced in a district of somewhat trian- 
gular shape (each side of the triangle being about 12 miles 
long), at one corner of which the town Xeres de la Frontera is 
situated. The use of the term has, however, been gradually 
more and more extended, until at last nearly every white 
Spanish wine is included in it. The town of Xeres forms the 
chief depot for sherry, and vast quantities are stored there in 
warehouses called bodegas . In Spain, unlike to what is the 
custom in France or Germany, the wine is but very rarely 
named according to the town or district where it is grown ; 
indeed, it would seem that the system under which the wine 
trade of Xeres is carried on renders such a method of classi- 
fication impossible. The wine is, however, frequently distin- 
guished according to the particular flavour it possesses, as 
Amontillado, for example. Spain produces about 140,000,000 
gallons of wine yearly, of which about 4 ? 000 ? 000 are the pro- 
duce of the Xeres district. 
All sherries, even those imported as natural sherry, are for- 
tified, and their alcoholic strength depends, therefore, upon the 
amount of spirit added ; it varies usually between 15 and 22%. 
The amount of acid present is, generally speaking, less than in 
the preceding wines, though not nearly to the extent their taste 
• Among a very great number of wines analysed, other than Greek, I 
have found aldehyde in only two samples, one a Sautern the other a Rhine 
wine. In both instances the bottles of wine had purposely been placed, for 
nearly a year, upright and badly corked, in an ordinary sitting-room. 
