The use of the blowpipe, in the qualitative and quantitative examination of minerals, ores, furnace products and other metallic combinations / Edited, with emendations, by Dr. Sheridan Muspratt. With a preface by Baron Liebig.

  • Plattner, Carl Friedrich, 1800-1858.
Date:
1850
Catalogue details

Licence: Public Domain Mark

Credit: The use of the blowpipe, in the qualitative and quantitative examination of minerals, ores, furnace products and other metallic combinations / Edited, with emendations, by Dr. Sheridan Muspratt. With a preface by Baron Liebig. Source: Wellcome Collection.

    99/440 (page 75)
    the platinum, and can then be crushed with the pestle of the agate mortar. In most cases the water can he raised to the boiling point, and the mass thus easily dissolved; but if a titaniferous mineral be melted with bisulphate of potassa in order to render the titanic acid soluble, the water must not be raised to the boiling point, as otherwise the titanic would not be dissolved, and even that part which was dissolved at a low temperature would be again precipitated. The manner of treat¬ ing the solution, and the residue which could not be converted into sulphates, will be more fully entered upon hereafter, when we come to speak of the qualitative examination of earths and metals. {? 5) PRECIPITATION (BY CRYSTALLIZED OR PULVERULENT REAGENTS) OF SINGLE CONSTITUENTS DISSOLVED IN FLUIDS. If it be necessary to decompose a clear solution with a dry salt, the acid or base of which is capable of combining with one of the constituents of the dissolved salt, and as a compound insoluble in this fluid is precipitated, the fluid must in most cases, after the addition of the salt, be slightly heated, in order that it might easily dissolve, and thus serve as a reagent. In some cases it is also better to warm the liquid before the addition of the salt, as in this case the precipitate is instantly produced. Thus, for example, baryta and strontia can be preci¬ pitated by pulverized bisulphate of potassa; lime by crystallized oxalate of ammonia; magnesia by microcosmic salt in crys¬ talline grains; phosphoric acid by a crystal of nitrate of silver; chromic acid by acetate of lead, &c. The quantity of the reagent used each time cannot be accurately estimated, as it entirely depends upon the quantity of the substance to be precipitated. (§ 6) DECANTATION, FILTRATION, AND EDULCORATION. In cases where only one substance is to be sought, in the clear liquid which covers a residue or precipitate, it is only necessary to pour off carefully the greater part of the liquid.