Improvement in Glowing Nets for Gaslight.
Year: 1896

page_text: Date of Application, 13th Feb., 1896-Accepted, 16th May, 1896
COMPLETE SPECIFICATION.
Improvement in Glowing Nets for Gaslight.
We, HERRMAN BURKERT, Merchant, Anklamerstrasse 19, and RICHARD
SEEMANN, Doctor, Chemist, Elsasserstrasse 7, both of Berlin in Germany do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
The improvement, which is the subject of this invention consists in the employment
of a mixture of thorium and elements of the chrome-group, preferably of thorium
and uranium, as material for the glowing nets for gas-light. The proportion of the
quantities of the elements in mixture is to be chosen thus, that the oxide of thorium,
obtained by burning afterwards, diminishing the lighting power, becomes neutralized
by influence of oxides of the chrome-group, especially by oxide of uranium.
The said proportion is not once for always alike, because the nitrate of thorium,
which is to be employed, instead of the element thorium itself, as raw material is
not to be had pure; the proportion therefore must always be ascertained according
to the quality of the nitrate of thorium to hand. However, the proportion's
deviation will remain in moderate limits, so that one per cent. oxide of uranium will
always give the oxide of thorium strongest power of emission.
As known, till now the glowing-nets are made of magnesia in mixture with
zirconium, or with the so called rare earths, i.e. with metal-earths of the cerium-
group (scandium, yttrium, lanthanum, didymium, ytterbium, erbium, etc.), and
lately also thorium, which does not belong to the cerium-group, is sometimes
employed in the mixture.
The inventor of the new improvement, has ascertained, in making numerous
experiments, that not only the so called rare earths (of the cerium-group) are of
the nature, to increase the lighting power of the gas flame of a Bunsen burner,
when mixed with magnesia and with or without a little thorium, but that the same
effect will be obtained by the mixing of metals of the chrome-group, especially of
uranium with thorium, without employing any magnesia, zirconium, or elements of
the cerium-group.
The inventor came to his improvement, whilst the experiments with several
oxides of thorium, giving cause to doubt the elementary nature of this metal-earth
and teaching, that some not yet discovered accompanying element is of the nature
to be neutralized by an element of the chrome-group, preferably by uranium.
The results of the experiments led to fact, that elements of the cerium-group as
well as magnesia are superfluous for the making of glowing-nets, and that the light
power, as already remarked, is profitably favored by nets of thorium-uranium or
thorium-chrome and the like, in spite of the effect of the magnesia and zircon nets
presently in use.
Having now particularly described and ascertained the nature of this said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
Glowing nets for gaslight of a material consisting of a mixture of thorium with

page_text: elements of the chrome-group, preferably with uranium, without any use of
magnesia, zirconium and elements of the cerium-group.
Dated this 11th day of February 1896.
HERRMAN BURKERT and
DOCTOR RICHARD SEEMANN,
By their Agent F. H. Haase.