250 J. Nickiés on Changes in Wine. 
Art. XXVIL—On certain Changes in Wine; by J. NICKLES.’ 
AMONG the different substances contained in wine, one of the 
most characteristic and constant, in connection with alcohol and 
water, is the bitartrate of potassa. Since a wine will not be 
accepted as a natural product if it Jacks this salt, it is well 
known that the manufacturers are always careful to add the 
bitartrate of potassa to spurious wine. Nothing has ever 
changed this opinion, although numerous chemical researches 
have been made every year with the different wines produced in 
France. Natural wine always contains a proportion more or less 
appreciable of cream of tartar (bitartrate of potassa), if the wine 
has not undergone any change. Through recent investigations 
made at Lyons and at Montpellier it has been discovered that the 
bitartrate of potassa may be wanting in wines which have ut 
dergone decomposition, especially in such wine as has become 
iter. Wine affected in this manner is known in France under 
the name of “changed wine” (vin tourné), It is very disagree 
able to the taste, and gives by distillation volatile acids in mue 
greater quantity than are furnished by normal wine. 
t has also been remarked that “changed wine” contains more 
potassa than wine of the same province which has not beet 
spoiled. But sugar and glycerine are not more abundant m such 
wine; on the contrary there appears lactic acid, which depends 
upon sugar for its production, and also another acid with the 
formula C,H,O,, which is the formula for propionic acid, . 
which, as we shall see below, is here applicable to an isomerl@ 
acid. 
It was at first thought that this volatile acid was derived — 
glycerine, which is normally contained in wine. But its one 
is now explained, by a fact which we discovered in 1846 an 
ay 
d also 
as We 
mie, 
he production of an acid C,H,O, from the b 
from the acetic acid may be rendered intelligible by means of 
following equation: 
2" 
 ©,8,0,+C,H,0,=C,,H,,0,: and CasHis20 0-0, 14% () 
[Acetic acid + butyric acid. ] __ [Butyro-acetie acid.] 
? Communicated to this Journal by the author. 
