BY CHEMICAL REAGENTS. 347 



of all Eoussillon. After the decomposition of blue 

 colouring matter, Tavella, Langlade and Port wine 

 are rendered least turbid by a yellow precipitate ; then 

 come in rotation, Burgundy, Bordeaux, Hermitage, 

 Burgundy- Pommard, Narbonne, Eoussillon, Benicarlo, 

 the last of which are very turbid. 



Nitrate of silver added to white wine forms a very 

 small precipitate in Champagne and Ehine wine ; none 

 in Muscadel, Madeira, white Cotes, white Bergerac, 

 Bordeaux-Sauterne ; in Teneriffe more, and most of all 

 in Lachryma Christi. In red wines, a very small preci- 

 pitate is formed in Bordeaux, Burgundy, Port, Her- 

 mitage, Tavella, Langlade, Burgundy-Pommard, St. 

 George, a larger one in JSTarbonne, Benicarlo, Eous- 

 sillon. They are all somewhat diminished by the addi- 

 tion of nitric acid, the precipitate of Burgundy-Pom- 

 mard most so, being almost re-dissolved, whilst much 

 chloride of silver remains undissolved in Benicarlo. 



Ammonia makes all white wines brown, Cham- 

 pagne, white Cotes, and white Bergerac least so ; 

 Bordeaux-Sauterne, Madeira, TenerifFe, Ehine wine, 

 Muscadel more so; and Lachryma Christi quite 

 brown. 



Among red wines, ammonia gives the colour of 

 Ehine wine to Port and Tavella. In the following 

 wines it gave rise to a dirty brown green precipitate, 

 least in Burgundy, more in Hermitage, and most in 

 Bordeaux, Langlade, Burgundy-Pommard, St. George, 

 Eoussillon, Narbonne, Benicarlo. In all of them the 



