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.

  • Karl Friedrich Plattner
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.

    117/440 (page 93)
    rally in combination with Sulphate and Carbonate of Lime, and Chloride of Calcium; and, (<?) With Silicic Acid, in various silicates of diflPerent bases, as for example, in Felspar [K 0, Si 0^ + AP 3 Si O^] ; Leucite [3 K O, 2 Si 0^ -h 3 AP 0^, 2 Si 0^ ] ; Apophyllite [K 0, 2 Si 0^ + 8 (Ca 0, Si O^) + 16 aq], Votassa-Tour- maline (Schorl) ; and in some micaceous minerals, &cA Examination for Potassa. The easily-fusible salts of potassa, with the exception of the phosphate and borate, are recognized when held in the points of the forceps, no soda being present, by the intense violet color given to the outer flame. If the mineral contains a small quantity only of potassa, no coloring will ensue, unless the splinter of it is held properly in the apex of the flame; great care must also be taken to have the assay operated upon, free from all extraneous matters. When soda or lithia is also an ingredient of the mineral, this mode is not applicable, as the flame will be colored yellow by the former, and red by the latter. Harkort resorts to the following method for the determination of potassa, when the quantity of this alkali is not too small. Oxide of nickel is dissolved in borax, until the glass, upon cooling, assumes a dark brown color; to this glass is then added a portion of the substance under examination, and the mixture is treated in the oxidating flame; if the glass upon cooling retains its brown color, potassa is either absent or in too minute a quantity to be detected; but if, on the other hand, the bead acquires a bluish tint, similar to a diluted solution of oxide of nickel in ammonia, it indicates the presence of this alkali. Lampadius observes. * Potassa is found also in Murchisonite, Raphilite, Chroin-mica, Diploite, Nuttalite, Finite, Elaolite, Nepheline, Eyakolite, Couzeranite, Weissite, Tachylite, Humboldtilite, Agalmatolite, Rosite, Polyargite, Zeagonite, Antrimolite, Gigan- tolite, Chabasite, Gmelinite, Phakolite, Pyrargillite.—Ed.