A Manual of Blow-pipe-analysis: And Determinative Mineralogy

Front Cover
T. E. Zell, 1866 - Blowpipe - 159 pages
 

What people are saying - Write a review

We haven't found any reviews in the usual places.

Other editions - View all

Common terms and phrases

Popular passages

Page 35 - The experiment with borax is generally made on platinum wire, where the color of the bead is more readily observed ; Ch. is used only in such cases where the substance under examination contains metallic oxides which are easily reduced. It is not sufficient to observe the color of the bead after cooling ; but all changes of color which take place during the action of the flame, and through all the various stages of cooling, should be carefully noticed. Some substances possess the property of forming...
Page 55 - ... bead is then taken from the charcoal, enveloped in a piece of paper, and struck lightly with a hammer, by which means the phosphuret of iron is separated from the surrounding flux. It exists as a metallic-looking button, attractable by the magnet, frangible on the anvil, the fracture having the colour of iron. If the substance under assay contained no phosphoric acid, the iron wire will keep its form and metallic lustre, excepting at the ends, where it will be oxidated and burnt. The substance...
Page 21 - A mouth-piece of box-wood or ivory is convenient, though not necessary. 2. Any kind of flame may be used for the blow-pipe, provided it be not too small. Some of the older chemists used common candles in preference, and it must be confessed that, in the majority of cases, the heat produced by the flame of a good sperm candle is quite sufficient. Berzelius recommended an oil lamp with a flat wick, which is now in general use as
Page 42 - ... open glass tube, evolve sulphurous acid and yield a sublimate of arsenous oxide. To show in a very decisive manner the presence of arsenic in any of its combinations with sulphur, the powdered assay [No. 80] is mixed with four volumes of neutral oxalate of potassa and a little charcoal powder, or with six parts of a mixture of equal parts of cyanide of potassium and carbonate of soda, the mass introduced into a tube sealed at one end, and heat applied, at first very gently but gradually raised...
Page 63 - Scapolite ; crystalline variety. 6. Orthoclase; white cleavable variety. 7. Quartz ; transparent. 8. Topaz; transparent. 9. Sapphire; cleavable varieties. 10. Diamond. To test the hardness of a mineral we may proceed in two different manners: firstly, by attempting to scratch it with the minerals enumerated in the scale, successively, or, secondly, by abrasion with a file. If the file abrades the mineral under trial with the same ease as No. 4, and produces an equal depth of abrasion with the same...
Page 63 - Breithaupt, is as follows: 1. Talc; common laminated light-green variety. 2. Gypsum ; crystalline variety. 3. Calcite; transparent variety. 4. Fluorite; crystalline variety. 5. Apatite; transparent variety. 6. Orthoclase; white cleavable variety. 7. Quartz; transparent. 8. Topaz; transparent. 9. Corundum; cleavable varieties. 10. Diamond.
Page 63 - ... scratch a smooth surface of the successive members of the scale with a sharp corner of the substance to be examined ; thus, if it scratches fluor-spar and is scratched by apatite, the hardness is between 4 and 5. Or again, the relative hardness of a mineral may be determined by abrading one of its edges with a file. If the file abrades the mineral under trial with the same ease as fluor-spar, and produces an equal depth of abrasion with the same force, the hardness is said to be 4. If the mineral...
Page 164 - Sesquioxide of Cerium; on cooling, yellow; enamel-like by flaming. Sesquioxide of Iron ; on cooling, yellow. Sesquioxide of Uranium ; on cooling, yellow ; enamelyellow by flaming. Sesquioxide of Chromium ; on cooling, yellowish-green. Sesquioxide of Iron, containing Manganese ; on cooling, (_ yellowish-red.
Page 62 - A set of minerals, representing the scale of hardness, being not always at hand, it will be useful to give a series of substitutes for them, as arranged by Mr. Chapman: 1. Yields easily to the nail. 2. Yields with difficulty to the nail, or merely receives an impression from it. Does not scratch a copper coin. 3. Scratches a copper coin; but is also scratched by it, being of about the same degree of hardness. 4. Not scratched by a copper coin; does not scratch glass. 5. Scratches glass, though rather...
Page 127 - Scolecite, on being heated, curls up like a worm, and finally melts to a bulky, shining slag, which in the inner flame becomes a vesicular, slightly translucent bead; hardness, 5.5.

Bibliographic information