A short manual of analytical chemistry : qualitative and quantitative organic and inorganic following the course of instruction given in the laboratories of the South London School of Pharmacy / by John Muter.

  • Muter, John, 1841-1912.
Date:
1903
Catalogue details

Licence: In copyright

Credit: A short manual of analytical chemistry : qualitative and quantitative organic and inorganic following the course of instruction given in the laboratories of the South London School of Pharmacy / by John Muter. Source: Wellcome Collection.

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    DECANTA TION—FILTRA 7 ION—DISTILL A TION. shown in fig. 3. These are kept in a stand (fig. 4) having holes for the reception of tubes actually in use, and also a row of pegs upon which freshly- Fig. 3- Fig-. 4. washed tubes may be inverted to drain. Fig. 5 illustrates the appliance used to hold tubes when their contents are to be boiled, and fig. 6 shows the brush used for cleansing them. In quantitative analysis precipitation is generally performed in beakers. These are very thin tumblers made of glass, free from lead, and annealed so as to permit their use with boiling liquids without risk of fracture. Precipitates are separated from the supernatant liquor by one of two methods. First:— IV. DECANTATION, which consists in allowing the precipitate to settle to the bottom, and pouring off the clear liquor. This is best done by the use of a glass rod held as shown in the illustration, fig. 7. Second :— V. FILTRATION, which consists in transferring the whole to a piece of folded filtering-paper or cloth placed in a funnel, so that the liquid passes through, while the precipitate remains. The liquor which has thus passed through the filter is called the filtrate. Specially prepared circular papers for filtration are sold, and they have only to be folded to fit the funnel for which they are destined. The illustrations show, fig. 8 ^a), the circle of paper, and (b) the same as folded for use, while fig. 9 represents the whole arrangement ready for use. VI. DISTILLATION. When a liquid is converted into vapour by the aid of heat, and the vapour is passed through a cooling apparatus, called a condenser, its latent heat is
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