_For Tokay_:-- Bagnols 80 litres. Syrup of raisins 10 „ Dried elder flowers 300 grammes. Infusion of white raspberries 2 kilos. „ „ walnuts 1 kilo. Alcohol 6 litres. Port is frequently flavoured with a mixture of elderberry juice, grape juice, brown sugar, and crude brandy known as “_Jerupiga_.” Sherry often consists of Cape wine mixed with honey, bitter almonds, and brandy. Astringency is conveyed to wines, deficient in this quality, by means of tannin; and the property of forming a crust on the interior of the bottle is produced, especially in port, by the admixture of cream of tartar and gum. “Dryness” is also obtained by artificial methods. A preparation met with in the trade, and used for this purpose, has the following composition:[94]-- Per cent. Glucose 28·72 Glycerine 38·40 Tannin 4·10 Dextrine 3·14 Boracic acid 4·27 Cream of tartar trace Moisture and ash 21·37 ------ 100·00 ------ The colour of white wines is caused by the oxidation of the tannin present, but it is sometimes increased by the addition of the concentrated juice of highly-coloured grapes, or by means of a small proportion of caramel. The colour of natural red wine is due to the presence of _oenocyanin_, a bluish-black compound, chiefly contained in the grape skins, which is insoluble in water, but dissolves in acidulated alcohol. In Spain and southern France, a wine prepared from a vine known as the _Teinturier_, and possessing an intense bluish-red colour, is extensively employed for colouring of wines. There appears to be no doubt but that elderberries, black cherries, mulberries, and hollyhock are also frequently used as colouring agents. Souberian[95] mentions a mixture, termed _liqueur de fismes_, composed of elderberries, but also containing about 5 per cent. of alum, which is occasionally employed. The general use of several deleterious dyes, such as logwood, cochineal, and the aniline colours, is far more problematical. In regard to the last-mentioned agents, it has, however, been asserted,[96] that in a commune near Beziers, of 1800 inhabitants, magenta, to the value of 30,000 francs, is annually consumed in the adulteration of wine. It is also worthy of remark that an aniline preparation used in Spain for the artificial colouring of wine has recently been found to contain 1·62 per cent. of arsenic acid.[97]