Page:The New International Encyclopædia 1st ed. v. 03.djvu/227

* BLOWING-MACHINES. 197 BLOWPIPE. fell downward through a vortical pipo havinj» openings for the admission of air at its top, and terminating at its bottom in an air-tight reser- voir. The air sucked in at the top of the pii)e by the falling water rises to the top of this reser- voir from which it is piped off for use. while the water remains at the bottom and is drawn off b,- suitable valves or openings. There arc various other forms of l>lowing-machines: but they are of such limited ap]ilication. or have become so near- ly obsoU'tc. that they need not be described liere. The modern blow ers of greatest importance in me- chanical operations are the bellows, the blowing- engine, and rotary blowers of the fan. disk, and positive types. See Heating ATiD Vextil.^tiox. BLOWITZ, bl.yvitz. Henri Georges Ste- PHAXE Adolpii Offer de ( 18,32-100.3) . A French journalist. He was born at Blowitz. Pilsen, Bo- liemia. but early removed to France, where he was for many years a teacher of languages at Tours. Limoges, and JIarseilles. During this time he became known as a writer on European poli- tics, contributing to the Gazette du Midi and other journals. He was naturalized as a French citizen in 1870 and became a warm supporter of Thiers, and for his sen'ices in aiding in the sup- pression of the Commune at Marseilles in 1871 was decorated with the cross of the Legion of Honor. In July, 1871, lie began his long career as Paris correspondent of the London Times. His services on the Times have been noteworthy, in particular his revelation, in 1875, of the plans of the German military party for the second inva- sion of France, and his pul)lication of the entire text of the Treaty of Berlin before it was signed. He was one of the first newspaper men to see the value of the "interview." Besides having contrib- uted over 4000 columns to the London Times, he published FeuiUes vo- lantes (1858) ; Midi d qudtoize he u res. a com- edv: I'AUemagne et la Provence (1869); Le mnriage roi/al d'Espagne (1878) : Ine course a Constantinoide (1884). BLOWPIPE. A con- ical tube of metal ter- minating in a small oi)ening. and used in the arts for soldering metals, and in mineralogy and analytical chemistry for determining the nature of .substances. According to Berzelius, Anton von Swab, a Swedish counsel- or of mines, first used the blow[)ipe in 1738 to test minerals and ores. Its use extended from Sweden to Germany, and thence throughout the Continent of Europe and to England. Cronstedt, Bergman. Gahn. and Berzelius have successively introduced valuable improvements in the form of the blowpipe. The present form, however, is due to Plattner and ills successors in the Royal Saxon Mining Acade- my in Freiberg. iiLowpieEa. The blowpipe most commonly used in doing analytical work consists of a conical brass tube about 8 inches long, terminating at the wider end in a convenient mouthpiece made of horn or rubber, while at the lower end a small tube with a finely perforated nozzle and a platinum tip is inserted at right angles to the larger tube slightly above its end, the space below being in- tended as a chamber for the moisture from the breath. When the nozzle of the blowpipe is placed within an ordinary flame and a somewhat strong current of air is blown through it. the flame is projected in a lateral direction as a long, point- ed cone: the air thus supplied being sufficient for complete combustion, the flame is colored blue and is very hot. K the point of this flame is directed against metals, the latter are rapidly transformed into their oxides, and hence the flame is called an oxidizing flame. On the other hand, when the nozzle of the blowpipe is placed near but outside a flame, and a gentle current of air is blown through it, the flame retains its luminosity, and, owing to the presence in it of incandescent carbon, is capable of reducing oxides to the metallic state; whence the name, reducing flame. See also Fl.me. In certain tests the substance is heated before the blowpipe on a piece of charcoal, the forma- tion of colored coatings often indicating the nature of the compound ; thus, lead deiiosits on the charcoal a yellow coating of its o.xide. In other tests the substance examined is mixed with reagents, usually borax, sodium carbonate, mi- croeosmic salt, and cobalt nitrate. The first four of these form, with metallic oxides, colored glass-like beads which serve to determine the composition of the substance. With borax, a bottle-green glass bead is obtained when iron salts are present : an amethyst-colored bead in- dicates manganese, and a blue-colored bead, co- balt. Sodium carbonate and microcosmic salt also yield characteristic colored beads that serve to indicate the presence of certain ingredients. The solution of cobalt nitrate, when applied to a powder on a piece of charcoal, yields charac- teristic colors for certain compounds that are distinctive, notably the blue coloration for alu- minivnn salts. Blowpipe analysis is generally used for quali- tative determinations, and finds its greatest ap- ])lieation in fleld-work as an easy means for determining the composition of minerals. In certain cases, it is possible to make also a quan- titative estimation of ores, especially those of silver and lead, by the iLse of the blowpipe. But the insignificant quantity of the lUiiterial that is employed renders the result scarcely precise enough even for the purposes of technical analy- sis. The blowpipe is the common instrument used by goldsmiths and jewelers for soldering metals. It is also used by "lass-blowers in their work, but in their manipulations the form of the blow- pipe is usually the Bunsen blast-lamp, in which the heat of the gas-flame is increased by a cur- rent of air that is supplied from a bellows. Consult: H. B. Cornwall, Manual of Blow- jiipe Anali/sis. Qualitative and Quantitative, nnth a Complete Si/slcm of Determinative Min- eralogii (New York, 1891): V. F. Plattner, Manual of Qualitative and Quantitative Analgsis uyith the Blowpipe, trans. Cornwall (New York,