368 ADULTERATION OF WINE. 



Pelouze and Fremy assert that basic acetate of lead 

 gives rise in pure wine to a grass greenish precipitate, 

 which is blueish if extract of logwood has been added, 

 and indigo, if Brazil wood has been employed. 



Iilhol recommends adding, first ammonia and after- 

 wards sulphide of ammonium. All genuine red wine 

 will become green, and that which has been artificially 

 coloured blue red, or violet. 



Miiller declares that carbazotate of potash gives a 

 dirty precipitate in genuine red wine, and produces a 

 crimson colour without precipitate in such as has 

 been coloured by means of poppies. 



Yogel says that sugar of lead occasions a precipi- 

 tate, which is green grey in genuine wine, indigo 

 blue if the wine has been adulterated with Brazil 

 wood, elder, or bilberries, and red if the wine has 

 been coloured with logwood, sandal-wood, or beet- 

 root. The wine itself becomes colourless if the colour 

 is caused by logwood or bilberries, but remains red 

 if elder-berries have been used. 



Vogel also says, that if potash be added to wine 

 which has been coloured with Brazil wood it yields a 

 red-brown colour, and becomes green if bilberries or 

 elder-berries have been used. 



Chevallier considers the discolouration produced by 

 potash as unsatisfactory, since . the alterations occa- 

 sioned by it vary according to the age of the wine.* 



Lime-water gives rise to a precipitate which is 



* Journ. de Cb. Med. Juin 1827, p. 306. 



