270 NATURE AND LIFE. 
ficially performed during the past year by several members 
of the syndical wine commission, at the suggestion of Pas- 
teur, contain decisive testimony on this point. Fine Bur- 
gundy wines, heated in bottle seven years ago to temper- 
atures varying between 131° and 149°, appeared, at the 
end of that time, superior to the same wines not so treated. 
Persons who spoke with some authority, Pasteur says, de- 
clared that heating would in time deprive the wine of its 
color. The contrary is the case, when the air is excluded 
during the process; the color grows livelier by heating. 
It was said that heating would in time alter the bouquet of 
fine wines, giving them dryness and too great age. On 
the contrary, the bouquet seems to be heightened with the 
lapse of time, more positively than with wines not heated. 
In the case of chambertin and volnay, particularly, the 
tasters noticed this fact. Pasteur was led by these studies 
to investigate the cause of the aging of wines, and he dis- 
covered that the phenomenon was due to slow oxidation. 
Wine kept in glass tubes completely filled and closely 
sealed does not age. By increasing and regulating the 
aération of wine, and particularly combining it with heat- 
ing, he succeeded in manufacturing in one month excellent 
old wine. In short, oxygen and heat, acting on wine in 
certain proportions, promote instead of hindering the devel- 
opment of those volatile principles to which the liquid owes 
its perfume and part of its flavor; but this discovery is addi- 
tional to those he was in searchof. What Pasteur did chief- 
ly look for and did find, in giving exact and methodical rules 
for heating wines, is a process, applicable on a great scale, 
for preventing the diseases from which the common vineyard 
products so often suffer, and that fortunate application isa 
result from his researches on fermentation generally. In 
the same way, in consequence of the examinations he under- 
took as to the share of microscopic organisms in the diseases 
of silk-worms, he was led to prescribe a practical way of 
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