A treatise on the origin, nature, and varieties of wine : being a complete manual of viticulture and œnology / y J.L.W. Thudichum and August Dupré.

  • Thudichum, J. L. W. (John Louis William), 1829-1901
Date:
1872
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on the origin, nature, and varieties of wine : being a complete manual of viticulture and œnology / y J.L.W. Thudichum and August Dupré. Source: Wellcome Collection.

    50/794 (page 22)
    The canes had yielded 2-44 per cent, of ash, and the murk, air-dry 6 65 ; 1 litre of wine had given 1*870 grammes of ash, or 0-19 per cent. ; the density of the wine assumed as 0960. It is clear that the ash of the canes contains less potash and more lime than that of the murk, and that the proportion of potash to lime is highest in the ash of the wine. Thus we have per cent, of potash contained in ash of canes 180, murk 36-9, wine 45'o; per cent, of lime contained in ash of canes 277, murk 107, wine 4‘9. But the relations of magnesia in those parts are different from those of potash and lime, for the percentage of magnesia contained in ash of canes is 6'1, murk 2'2, wine 9'2. The wine yields a very small percentage of ash compared to the other parts, and in conse- quence its percentage of alkalies is smaller than that of any other part of the vine ; but as it has lost much mineral matter during fermentation, the quantity of its ash is not the measure of the quantity of mineral matter removed by it from the soil: for this determination, the murk, before fermen- tation, has to be examined. It is of interest to ascertain the amount of mineral matter which a fruit-bearing branch of one summer’s growth con- tains. Berthier analysed such a branch, cut from a Gamay vine at Nemours, in October 1850, at the time of the vintage. Cane and leaves were examined together, but separately from the grapes. The diy branch and leaves weighed 450 grammes. The grapes weighed . . . 7° >> The branch yielded ash consisting of— Alkaline salts, 6'20 grammes, or 1 *38 per cent. Earthy salts 20^30 ,, or 472 „ Total ash 26^50 ,, or 5^90 „ The grapes yielded ash containing— Alkaline salts . i *56 grammes, or 2'25 per cent. Earthy salts . i'40 ,, or I'95 „ Total ash . 2'g6 ,, or 4'20 ,, The branch and leaves therefore contained 9 times as much