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34	QUANTITATIVE AGRICULTURAL ANALYSIS
The nickel grid through which the mixture flows at the top of
the burner causes the gas to burn exactly as though each mesh
were a small individual burner. The tip of the inner reducing
cone of each small flame is usually about one millimeter above
the top of the burner and, as all of the small flames unite to form

one large one, the result is a
highly concentrated flame,
every part of which is oxidiz-
ing in character except a zone
of about one millimeter in
depth, immediately above the
top of the burner. This is a
distinct advantage, especially
in heating platinum articles,
since platinum is easily dam-
aged by heating in a reduc-
ing flame.
A number of imitations
and modifications of the
M6ker burner are offered for
use at this time. Most of
these use the same combus-
tion principle, the burners
differing only in mechanical
features.
fig. 14.—Section of M£kcr burner.
Blast Lamp.—In order to
produce a higher temperature
a burner may be constructed
so as to consume a larger
quantity of gas, depending
for its complete combustion
upon admission of air under pressure. A burner so con-
structed is called a "blast lamp." Many forms of such burners
are in use.
The flame of the M£ker burner is nearly as hot as that of the
ordinary blast lamp using the same gas and it may be substi-
tuted for the blast lamp in many cases. There is also a M£ker
blast lamp, similar in construction to the one already described
but using air under pressure.