Historical introduction to chemistry / by T.M. Lowry.

  • Martin Lowry
Date:
1915
Catalogue details

Licence: In copyright

Credit: Historical introduction to chemistry / by T.M. Lowry. Source: Wellcome Collection.

    43/608 page 23
    Summary and Supplement A and B.—DISCOVERY AND PROPERTIES OF THE ACIDS. Vegetable Acids include :— Acetic acid, C2H402, from Vinegar (known to Geber) ; Tartaric acid, C4Hu06, from Tartar (Scheele, 1770) ; Benzoic acid, C7Hf,02, from Benzoin (Scheele, 1775) ; Uric acid, C5H4N403, from Bladder-stones (Scheele, 1776) ; Lactic acid, C3H0O3, from Sour Milk (Scheele, 1780); Oxalic acid, C2H204, from Oils (Scheele, 1783) ; Citric acid, C,;H807, from Lemons (Scheele, 1784) ; Malic acid, C4H605, from Apples (Scheele, 1786). Mineral Acids include :— Oil of Vitriol, Vitriolic acid, or Sulphuric acid, H2S04, pre¬ pared by distilling Alum (Geber) or Green Vitriol (Glauber). Aqua Fortis, Acid Spirit of Nitre, or Nitric Acid, HNOs, pre¬ pared by distilling Nitre and Alum (Geber) or Nitre and Oil of Vitriol (Glauber), 2KN03+H2S04—S>K2S04 + 2HN03. Spirit of Salt, Muriatic acid, or Hydrochloric acid, HC1, pre¬ pared by heating Salt and Oil of Vitriol, and collected in water (Glauber), eNaCI + H2S04—Na2S04 + 2HCI. Aqua Regia, a mixture of Aqua Fortis and Spirit of Salt prepared by adding Sal-ammoniac to Aqua Fortis (Geber), NH4C1 + HN03—> NH4NOs+ HCI, or by distilling a mixture of Nitre and Salt with Oil of Vitriol (Glauber). The acids as a class possess the following properties, though some of them may be lacking in the case of individual acids :— (а) General Properties : Sour taste; acids turn syrup of violets red and redden blue litmus ; the mineral acids are corro¬ sive when concentrated but harmless when dilute ; (б) Acids dissolve Alkalis and Chalk, liberating gas, eg., “ Vinegar upon Nitre (i.e., soda)” and upon Chalk, Na2C03 + 2C2H402—>2NaC2H302+ H20 + CO., CaC03 + 2C2H ,02—S>Ca(C2H302)2 + H20 + CO,2 ; Oil of Vitriol with Soda gives “ Glauber’s salt,” with Chalk gives “Gypsum” or “Selenite” (almost insoluble in water) Na2C03+ H2S04—> Na2S04 + H20 + CO, CaCOs + H2S04—CaS04 -f- H20 T C02;
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