The principles of chemistry : illustrated by simple experiments / by Julius Adolph Stöckhardt ; translated from the 3rd German ed. by C.H. Peirce.

  • Stöckhardt, Julius Adolph, 1809-1886.
Date:
1850
Catalogue details

Licence: Public Domain Mark

Credit: The principles of chemistry : illustrated by simple experiments / by Julius Adolph Stöckhardt ; translated from the 3rd German ed. by C.H. Peirce. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    tion of the wood with the oxygen, is also aeriform; but burning substances are extinguished in the newly- formed gas. If the bottle be rapidly whirled round, The gas formed by the combustion will escape, and atmos- pheric air will supply its place. Air contains free oxy- gen ; and a kindled shaving will burn in it for some time, but far slower and less briskly than in pure oxy- gen ; because common air contains only one fifth part of oxygen. Accordingly, a combustion in oxygen pro- ceeds five times more rapidly and violently than in at- mospheric air. 59. Experiment. — To prepare a larger quantity of oxygen, take one hundred grains of chlorate of potassa, and heat it in the same manner as described in the former experiment; the salt will soon melt, and after- wards boil. As soon as the boiling commences, the flame must be diminished, to prevent the mass from foaming over. When the liquid thickens, if some of the substance should be found adherent to the colder parts of the test-tube, approach it with the flame of the lamp, until it is again melted down. As soon as the gas ceases to be generated, draw the tube immediate/// from the water. 60. For collecting gases in larger quantities, the fol- lowing contrivance may be resorted to. Make a shelf out of slate or a piece of lead, Fig. 28. r some inches broad, and so long that it will rest about half way up the sloping walls of the vessel in which it is to be placed; bore a small hole through the centre of the shelf with some appropriate instrument. When wanted for use, pour into the vessel as much water as will be sufficient to cover the shelf