CHAPTEE X. 



COLOUEING MATTERS IN WINE. 



ALTH.OUGH there are almost innumerable shades of 

 difference in the colour of wine, they are all varieties 

 of two, the reddish and the yellowish colour. I say 

 reddish, for we know no kind of wine that is actually 

 red or yellow. "What we call red in wine is violet, a 

 mixture of blue and red. "We do not in chemistry 

 speak of the reddish wine as red, but designate its 

 hue by the term wine-colour ; it is the colour which 

 is imparted to litmus by means of boracic acid and 

 carbonic acid, and which, according to Malaguti, can 

 only be made to change into the red colour produced 

 by the action of hydrochloric acid on litmus, by the 

 addition of large quantities of these acids. 



"What we call yellow wine is not yellow, but pale 

 brown. For who has ever seen yellow wine ? Ma- 

 deira, and such like wines, are brown, but for the sake 

 of convenience we shall continue to call them yellow. 



Besides these, there are wines which every one 

 calls brown : those, namely, which have been boiled, 

 such as Tinto, and the like. "We will now direct our 

 attention to the cause of this variety of colour. 



