. The Canadian journal of industry, science and art. 16 A POPULAR EXPOSITION OF THE The acids used in these experiments may be conveniently kept in small glass bottles furnished with a long glass stopper, reaching to the bottom of the bottle, and with a glass cap to prevent the escape of corrosive fumes. Por geological purposes (testing calcareous rocks, &c.,) strong hydrochloric acid diluted with half its bulk of pure water, is principally used. The " specimen basket" may be provided near its upper edge with a little nest, or wicker-work pocket, for the reception of the acid bot
. The Canadian journal of industry, science and art. 16 A POPULAR EXPOSITION OF THE The acids used in these experiments may be conveniently kept in small glass bottles furnished with a long glass stopper, reaching to the bottom of the bottle, and with a glass cap to prevent the escape of corrosive fumes. Por geological purposes (testing calcareous rocks, &c.,) strong hydrochloric acid diluted with half its bulk of pure water, is principally used. The " specimen basket" may be provided near its upper edge with a little nest, or wicker-work pocket, for the reception of the acid bottle. Action of the Bloio-pipe.—The blow-pipe in its simplest form is merely a narrow tube of brass or other metal, bent round at one extremity, and terminating at that end in a point with a very fine orifice {a: fig. 21). If we place the pointed end of this instrument just within the flame (and a little above the wick) of a lamp or common candle, and then blow gently down the tube, the flame will be deflected into a horizontal position, and its heating powers will be wonderfully increased. Many minerals when held in the form of a thin splinter at the point of the blow-pipe flame, melt with the greatest ease; and some are either wholly or partially volatilized. Other minerals, on the contrary, remain unaltered; and thus, by the aid of the blow-pipe, we are often enabled to distinguish from one another, in a moment, various minerals which in external characters may be closely alike.* The blovr-pipe has, strictly, a three-fold application. It may be employed, as just pointed out, to distinguish minerals from one another; some of these being fusible, whilst others are infusible; some attracting the magnet after exposure to the blow-pipe, whilst others do not exhibit that reaction ; some imparting a colour to the . flame, others volatilizing, and so forth. Secondly, the blow-pipe may be employed to ascertain the general composition of a mineral, or the presence or absence of some
Size: 1696px × 1474px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1850, bookpublishertoron, bookyear1856
