ADULTEBATION OF WINE. 367 



The colour of the precipitate yielded by the fruits 

 of the dwarf elder and sugar of lead, varies according 

 to whether the juice is fresh or fermented. The pre- 

 cipitate from the fresh juice was blue grey, the liquid 

 beautiful violet, the precipitate from the fermented 

 iuice beautiful bright red. 



It has been suggested by Ness von Esenbeck to add 

 an equal volume of solution of alum (1 part to 12 

 parts water), to the wine, which makes the colour bright 

 red ; then a solution of carbonate of potash, but so that 

 all the alumina shall not be precipitated. After twenty- 

 four hours the colour of the precipitate must be com- 

 pared with that of the genuine wine, which gives a dirty 

 grey more or less reddish precipitate. If the wine 

 was coloured with Brazil wood, the precipitate will be 

 rose coloured ; if with logwood, grey violet ; with 

 cherries, beautiful violet ; with the fruit of the dwarf 

 elder, violet ; with bilberries, blue grey ; with poppies, 

 grey brown. Other varieties may also be observed 

 when excess of potash is added to pure wine. 



Batilliat proposes to add ammonia to red wine. 

 The colouring matter then becomes brown, and if tar- 

 taric acid be now put to it the colour of genuine wine 

 will not be restored, though that caused by artificial 

 colouring matters may. He is of opinion that potash 

 cannot be used instead of ammonia, because, although 

 it turns the wine brown, the original colour may be 

 restored by means of tartaric acid. When the potash 

 used was stronger, or had acted for some time, this 

 was not the case. 



