The Story-Book of the Fields 



out, we must retreat at once ; for the ex- 

 tinction of the taper shows the presence of the 

 gas and to proceed further would expose us to 

 sudden death. 



Let us go back to the wine. We have said 

 that the sugar which gives the sweet taste to 

 the must, the juice drawn from the grape, 

 changes its nature by fermentation and is 

 separated into two components — alcohol, 

 which remains in the fluid and transforms it 

 into wine, and carbonic acid gas, which is dis- 

 persed in the air. When this process is com- 

 pleted the wine is drawn off to separate it 

 from the residuum, consisting of the skins and 

 pips. The fluid will then contain a large 

 amount of water derived from the grapes, a 

 little alcohol from the lost sugar and a colour- 

 ing matter from the skins of the black grapes. 



White wine is made with white grapes, 

 the skins of which hold no colouring matter ; 

 but it can be manufactured just as well with 

 black grapes, however dark they may be. 

 The whole secret lies in pressing the crushed 

 grapes before they are allowed to ferment 

 and thus separating the juice from the skins. 

 When the skins have been removed the wine 

 will be white, even if made with black grapes. 

 The colouring matter of the grapes from which 



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