GLTJCIC ACID. 253 



again filtered in order to remove the chalk. If glucic 

 acid were contained in the wine, we should find it 

 here. Sugar could no longer exist. The liquid when 

 warmed with test solution of oxide of copper and 

 potash showed no reduction, therefore no glucic acid 

 was found in red Bordeaux wines. 



I do not, however, venture to assert that no glucic 

 acid exists in wine ; on the contrary, knowing how 

 quickly and easily the sugar in wine (which is so 

 liable to undergo change) may be resolved into glucic 

 acid, I consider it highly probable it does exist. But 

 glucic acid, even when combined with lime, may very 

 easily be resolved into apoglucic acid, and then 

 masked by the colouring matters of the wine. I 

 shall speak again of this matter in treating of the 

 decomposition of wine ; I do not therefore deny that 

 glucic acid is present in wine, but it is difficult to 

 prove it. 



