The Romance of Modern Chemistry
Forfatter: James C. Phillip
År: 1912
Forlag: Seeley, Service & Co. Limited
Sted: London
Sider: 347
UDK: 540 Phi
A Description in non-technical Language of the diverse and wonderful ways in which chemical forces are at work and of their manifold application in modern life.
With 29 illustrations & 15 diagrams.
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FLAME: WHAT IS IT?
is therefore fitted, not only with a glass cylinder at
the bottom to let the light out, but with an iron
cylinder above to shield the lamp from draughts.
When the Davy lamp is brought into an atmosphere
in which fire-damp is present, a so-called “ cap11 of pale
blue flame is seen surmounting the ordinary luminous
Fig. 8.—A flame of burning hydrogen is shown at (a). When this
flame is brought into an atmosphere charged with fire-damp or
marsh gas it is surmounted by a “cap,” the length of which
indicates the amount of dangerous vapour present. The caps
shown at (b), (c), and (d) represent what is seen when the atmos-
phere surrounding the flame contains one-half, two, and three
per cent, of marsh gas.
flame in the lamp. The length of this “ cap ” increases
as the percentage of fire-damp in the surrounding atmos-
phere rises. Hence it will be seen that to the experienced
eye the appearance of the Davy lamp flame serves as a
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