and particularly the Alicant Raisin Wine. 315 



pressed the must from some Alicant raisins ; but this thick 

 and muddy must produced no sensible effects upon soup. 

 M. Heraud then set the must which remained to ferment; 

 and he obtained a fine red wine, very pleasant although not 

 very mellow, and which precipitated the broth as well as 

 the true Alicant wine which M. Heraud had in his shop. 

 It is easy to see that the mucous and saccharine bodies 

 which render the must of Alicant viscous, keep the preci- 

 pitate suspended, as it happens with ink when strongly 

 gummed ; and that fermentation, by destroying a, part of 

 these viscous bodies, had rendered the play of the chemical 

 affinities quite free. It is thus that we extract gelatine from 

 quinces and other astringent fruits, without the tannin which 

 they contain forming any precipitate with the gelatine. 



The fat broth, well boiled and skimmed, contains, among 

 other principles, gelatine; and as of all the known vegetable 

 matters gelatine is most easily precipitated by tannin, it fol- 

 lows then, of course, that the latter principle exists in Ali- 

 cant wine and raisins. This tannin serves for the interme- 

 dium to the colouring principle, and keeps it dissolved in the 

 water ; also the colouring principle forms the greater part of 

 the precipitate ; not that the gelatine acts upon it, since it does 

 not act upon the ordinary red wines, but because in this case 

 the kind of colouring principle is united to that of the tan- 

 nin, its intermedium. The yellow colour of the tannin gives 

 the red wine of Alicant an orange cast. Upon precipitation 

 the colour becomes violet, because the malic acid remains 

 dissolved, and does not redden the colouring principle. The 

 latter would even become much bluer if it did not retain 

 some atoms of tartar. 



When the made wine is evaporated, the alcohol carries 

 off with it a part of the malic acid, and the residue becomes 

 .so much the more violet-coloured the less tartarous it is. 

 But in the juices of red fruits, and of the teinturier, the 

 malic acid, deprived of the intermedium of the alcohol and 

 retained by the saccharine body, remains lixed, in spite of 

 the operations they undergo, and preserves the red colour of 

 these juices. 



X 2 Wc 



