Chemistry / [Raphael Meldola].

  • Meldola, Raphael, 1849-1915.
Date:
[1914?]
Catalogue details

Licence: In copyright

Credit: Chemistry / [Raphael Meldola]. Source: Wellcome Collection.

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    stitiient or constituents, or is it chemically combined ? The answer to these questions will furnish further instructive illustrations of facts, methods, and principles. The fact that heated iron takes oxygen out of water suggests the use of this metal in order to find out what is left after the oxygen has been removed. In forming iron scale by plunging red-hot iron into water, it might be noticed that with the escaping steam there is a gas which, unlike the steam, does not condense on cooling. This gaseous product of the action of water upon hot iron is not easy to detect by such a rough and ready experiment; but by a refinement of method, and without in any way interfering with the principle by altering the materials, this gas can be readily obtained in any desired quantity. In practice, instead of using water, we use steam, which is the same substance in a different state of physical aggregation ; and the iron, in coarse fragments, such as wire or nails, is enclosed in a tube of porcelain or any suitable material that will stand the heat. The steam is passed through the heated tube, and the emergent gas collected by appropriate methods in any suitable vessel. At the end of such an operation, the iron will be found to have been more or less converted