116 LOUIS PASTEUR. 



itself felt in the vintage tubs. The wine is said to 

 turn, to rise, to spurt. The wine becomes slightly 

 turbid and at the same time flat and piquant. 

 When it is poured into a glass, very small bubbles 

 of gas form like a crown upon the surface. On 

 placing the glass between the eye and the light 

 and slightly shaking it, one can distinguish silky 

 waves shifting about and moving in different direc- 

 tions in the liquid. When the turned wine is in a 

 cask, it is not unusual to see the bottom of the cask 

 bulge a little, and sometimes a leakage takes place at 

 the joints of the staves. If 'a little opening is made, 

 the wine spurts out, and that is the reason why the 

 wine is said to spurt. 



Authors who have written on the subject of 

 wine attributed this malady to the rising of the lees. 

 They believed that the deposit which always exists in 

 greater or less quantities in the lower part of the 

 cask rises and spreads itself into all the mass of the 

 wine. 



Nothing can be more inexact. If this phenomenon 

 is sometimes produced that is to say, if the deposit 

 rises into the mass of wine the effect is due to a 

 sudden diminution of the atmospheric pressure, as in 

 times of storm, for example. As the wine is always 

 charged with carbonic acid gas, which it holds in 

 solution from the moment of fermentation, one can 

 conceive that a lowering of barometric pressure would 



