. Chemistry: general, medical, and pharmaceutical, including the chemistry of the U. S. Pharmacopia. A manual on the general principles of the science, and their applications in medicine and pharmacy. ross the glassat the required point, then clasping the tube, the scratch beingbetween the hands, and pulling the portions asunder, forcebeing exerted in a slightly curved direction, so as to open outthe crack which the file has commenced) : The tube is fixed inthe cork through a round hole made by the aid of a red-hotwire, or, better, by a rat-tail file, or, best of all, by one of a setof cork-bo
. Chemistry: general, medical, and pharmaceutical, including the chemistry of the U. S. Pharmacopia. A manual on the general principles of the science, and their applications in medicine and pharmacy. ross the glassat the required point, then clasping the tube, the scratch beingbetween the hands, and pulling the portions asunder, forcebeing exerted in a slightly curved direction, so as to open outthe crack which the file has commenced) : The tube is fixed inthe cork through a round hole made by the aid of a red-hotwire, or, better, by a rat-tail file, or, best of all, by one of a setof cork-borers—pieces of brass tubing sharpened at one endand having a flat head at the other. Fit the cork and test-tube OXYGEN. 17 to each other accurately and closely, but not so tightly as tobreak the test-tube. Setting aside the test-tube for a few min-utes, proceed to bend the long piece of tubing to the mostconvenient shape for collecting the gas. To Bend Glass Tubes.—Hold the part of the tube requiredto be bent in any gas or spirit flame (a fish-tail gas-jet, forexample, Fig. 1), constantly rotating it, so that about an inchof the glass becomes heated. It will soon be felt to soften, Fig. Softening and Bending Glass Tubes. and will then, yielding to the gentle Fig. 2. pressure of the fingers, assume any required angle. In the present case the tube should be heated at about four inches from the extremity to which the cork is attached, and bent to an angle of 90 degrees (Fig. 2). Source of Heat.—The source of heatfor the test-tube may be the flame of anordinary spirit-lamp, or, still better wherecoal-gas is procurable, a mixture of thelatter with air. Gas-lamps, especiallyconstructed to burn a mixture of coal-gasand air, are sold by chemical-apparatusmanufacturers. (See Figs. 3 and 7.) Collection, etc. (continued).—Fit thecork and bent tube into the test-tube;the apparatus will then be ready for delivering gas at aconvenient distance from the heated portion of the arran
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