<ENA1S T TEIN GUM. 265 



proved by the fact that their flavour is greatly im- 

 proved by the addition of cenanthin. 



Faure, in order to obtain this cenanthin, precipitates 

 the colouring matter and tannic acid with isinglass, 

 evaporates the colourless extract to the thickness of 

 extract, dissolves the extract in alcohol of 85 per cent, 

 which takes up such substances as have escaped the 

 isinglass, whilst the cenanthin collects together as a 

 sticky mass, it is re-dissolved in weak alcohol and pre- 

 cipitated by alcohol of 85 per cent. 



We have already given Eaure's estimate of the 

 amount of cenanthin in different wines. (P. 172.) 



In preparing oenanthin in the manner previously 

 recommended difficulties will occur. It is, for example, 

 impossible to free red wine from colouring matter^ by 

 means of isinglass or albumen, or even by boiling it 

 in excess of albumen. The wine becomes very pale, 

 but not colourless. Nor is it possible to render the 

 wine perfectly colourless by adding isinglass and 

 tannic acid. The reason of this is very clear, the 

 colouring matter of wine does not combine with isin- 

 glass or albumen, but clings to them ; and as it is 

 soluble in weak alcohol and tartaric acid it is partially 

 dissolved, and it cannot be included in a coagulum of 

 tannic acid and isinglass, or albumen, even when it is 

 coagulated by boiling. 



But if wine cannot be freed from colouring matter 

 by isinglass, as was known, indeed, to Eaure, it is 

 equally useless to precipitate the wine first with ism- 



