Improvements in Illuminant Appliances for Burners.
Year: 1886

page_text: Date of Application, 13th Mar., 1886.
Complete Left, 11th Dec., 1886.
Complete Accepted, 21st Jan., 1887.
[Communicated from abroad by CARL AUER VON WELSBACH, of No. 63, Gumpendorfer
Strasse, in the City of Vienna, Austria, Doctor of Philosophy.]
Improvements in Illuminant Appliances for Burners.
I, OLIVER IMRAY of No. 28 Southampton Buildings, Chancery Lane in the County
of Middlesex, Fellow of the Institute of Patent Agents, do hereby declare the nature
of this invention to be as follows:-
In the Provisional Specification No. 15286 filed on the 12th December 1885 by
Carl Auer von Welsbach is described the manufacture of an illuminant appliance for
burners, in the form of a cap or hood made by impregnating fabric with solutions of
salts of certain rare metals and then by the heat of the flame consuming the fabric so
that the skeleton remains, consisting mostly of the oxides, of the metals, which, heated
to incandescense, gives out a brilliant light. The said Carl Auer von Welsbach,
continuing his researches since filing the provisional specification No. 15286 of 1885,
has found that certain substances other than those mentioned therein can be advan-
fageously employed in producing such illuminant appliances, and has communicated
the present invention which I will proceed to describe. For making an illuminant
cap or hood to produce, when heated, a white light, the following substances may
be used:
1, Pure Thorinum Oxide makes a hood which is rigid when incandescent.
2, A mixture of Thorinum oxide about 3 parts with 2 parts of magnesia makes a
hood which is flexible when incandescent.
3, A mixture of Thorinum oxide, Zirconium oxide and Yttrium oxide in nearly
equal proportions gives a slightly yellow tint to the white light.
4, A mixture of Thorinum-oxide, Zirconium oxide-and Lanthanium oxide in nearly
equal proportions, the Lanthanium a little in excess, gives a very brilliant light, and
ile hood is flexible when incandescent.
5, A mixture of Thorinum oxide and Lanthanium oxide in equal parts, with about
half a part of magnesia makes a hood which is flexible when incandescent.
6, A mixture of Thorinum oxide about 3 parts with 1 of magnesia and one of
alumina gives a hood which is very flexible when incandescent.

page_text: In the mixtures which include Lanthanium oxide, for a portion of that substance
Yttrium oxide may be substituted.
When a yellow light is desired, the mixture may be
7, Thorinum oxide and Lanthanium oxide in equal proportions.
For an orange light, it may be
8, Thorinum oxide and Neodium oxide in equal proportions.
For a greenish light, it may be
9, Thorinum oxide and Erbium oxide in equal proportions.
In the mixtures 7, 8 and 9 Zirconium oxide may be substituted for a portion of the
Thorinum oxide. Though magnesia and alumina can be employed, as in 5 and 6, it is
better to avoid the use of much of these substances, as hoods containing them are not
so durable as those from which they are absent.
For impregnating the fabric, solutions of the salts of the metals are employed as
described in the previous specification, but it is not necessary that all the substances
should be in solution. Some of the salts in pulverulent amorphous or finely crystalline
condition may be mixed with a solution of salts of the other metals so as to produce a
thickish liquid in which the undissolved salt is suspended. With this liquid the fabric
can be repeatedly soaked, surplus liquid being pressed out between the successive
impregnations, until there is uniform distribution of the substances over the fabric.
In preparing the solutions, a number of different salts may be employed. Nitrates
are generally soluble, so also, but in less degree, are the sulphates, chlorides, iodides,
bromides, also some organic salts such as acetates or formiates. Generally the fluorides,
carbonates, hydroxides and many of the organic salts are insoluble or soluble with
difficulty. Those products which are insoluble or only partially soluble may, however,
be employed, as, above described, in admixture with solutions of soluble salts.
When the fabric has been thoroughly impregnated and dried and formed into the
desired hood shape, it is not necessary to treat it with ammonia as described in the
former specification; it may at once be subjected to the action of heat, care being
taken to apply the heat first to its upper part and then gradually downwards, as may
be done by lowering the burner flaine within the hood or raising the hood. It is of
advantage to strengthen the hood by drawing through it in various directions stronger
threads, themselves impregnated with the illuminant substance, or fine platinum wires
may be used. Also the hood may consist of several thicknesses of fine open fabric,
or of a single fabric pleated or folded, or instead of using fabric a number of separate
impregnated threads may be hung from a ring of platinum wire so as to surround the
flame. The attachment. of the hood or threads to the suspending ring should be
strengthened by serving the upper part before burning with a mixture of nitrates of
the metals employed and magnesium nitrate. Usually the hood is protected by being
enclosed within a glass chimney like that of an argand lamp, but when a chimney is
not used, it may be surrounded by a cage of fine platinum wire.

page_text: COMPLETE SPECIFICATION.
Improvements in Illuminant Appliances for Burners.
I, OLIVER IMRAY of No. 28 Southampton Buildings, Chancery Lane in the County
of Middlesex Fellow the Institute of Patent Agents 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 :-
In the Specification No. 15286 of 1885 of Carl Auer von Welsbach is described the
manufacture of an illuminant appliance for burners, in the form of a cap or hood made
by impregnating fabric with solutions of salts of certain rare metals and then by the
heat of the flame consuming the fabric so that the skeleton remains consisting mostly
of the oxides of the metals, which, heated to incandescence, gives out a brilliant light.
The said Carl Auer von Welsbach, continuing his researches since filing the provisional
specification No. 15286 of 1885, has found that certain substances other than those
mentioned therein can be advantageously employed in producing such illuminant
appliances, and has communicated the present invention which I will proceed to
describe. For making an illuminant cap or hood to produce, when heated, a white
light, the following substances may be used:
1. Pure Thorinum Oxide makes a hood which is rigid when incandescent.
2. A mixture of Thorinum oxide about 3 parts with 2 parts of magnesia makes a
hood which is flexible when incandescent.
3. A mixture of Thorinum oxide, Zirconium oxide, and Yttrium oxide in nearly
equal proportions gives a slightly yellow tint to the white light.
4. A mixture of Thorinum oxide, Zirconium oxide and Lanthanum oxide in nearly
equal proportions, the Lanthanum a little in excess, gives a very brilliant light, and
the hood is flexible when incandescent.
5. A mixture of Thorinum oxide and Lanthanum oxide in equal parts, with about
half a part of magnesia makes a hood which is flexible when incandescent.
6. A mixture of Thorinum oxide about 3 parts with one of magnesia and one of
alumina gives a hood which is very flexible when incandescent.
In the mixtures which include Lanthanum oxide, for a portion of that substance
Yttrium oxide may be substituted.
When a yellow light is desired, the mixture may be
7. Thorinum oxide and Lanthanum oxide in equal proportions.
For an orange light it may be
8. Thorinum oxide and Neodymium oxide in equal proportions. As the name Neody-
mium is new it is necessary to explain that it is one of two metals constituting what is
generally supposed to be a simple metal Didymium.
For a greenish light it may be
9. Thorinum oxide and Erbium oxide in equal proportions.
In the mixtures 7, 8 and 9, Zirconium oxide may be substituted for a portion of the
Thorinum oxide. Though magnesia and alumina can be employed, as in 5 or 6, it is
better to avoid the use of much of these substances, as hoods containing them are not so
durable as those from which they are absent.

page_text: For impregnating the fabric, solutions of the salts of the metals are employed as
described in the previous specification, but it is not necessary that all the substances
should be in solution. Some of the salts in pulverulent amorphous or finely crystalline
condition may be mixed with a solution of salts of the other metals so as to produce a
thickish liquid in which the undissolved-salt is suspended. With this liquid the fabric
can be repeatedly soaked, surplus liquid being pressed out between the successive
impregnations until there is uniform distribution of the substances over the fabric.
In preparing the solutions a number of different salts may be employed. Nitrates
are generally soluble, so also, but in less degree, are the sulphates, chlorides, iodides,
bromides, also some organic salts such as acetates or formiates. Generally the fluorides,
carbonates, hydroxides and many of the organic salts are insoluble or soluble with
difficulty. Those products which are insoluble or only partially soluble may, however,
be employed as above described, in admixture, with solutions of soluble salts.
When the fabric has been thoroughly impregnated and dried and formed into the
desired hood shape, it is not necessary to treat it with ammonia as described in the
former specification, it may at once be subjected to the action of heat, care being taken
to apply the heat first to its upper part and then gradually downwards as may be done
by lowering the burner flame within the hood or raising the hood: It is of advantage
to strengthen the hood by drawing through it in various directions stronger threads
themselves impregnated with the illuminant substance, or fine platinum wires may be
used. The hoods may be made as tubes woven or knitted some parts especially the
upper parts being made stronger by using in these parts meshes of smaller size than
the meshes generally, or by double weaving or knitting of the parts that require
greater strength. Also the hood may consist of several thicknesses of fine open fabric,
or of a single fabric pleated or folded, or instead of using fabric a number of separate
impregnated threads may be hung from a ring of platinum wire so as to surround the
flame. The attachment of the hood or threads to the suspending ring should be
strengthened by serving the upper part before burning with a mixture of nitrates' of
the metals employed and magnesium nitrate. Usually the hood is protected by being.
enclosed within a glass chimney like that of an argand lamp, but when a chimney is
not used, it may be surrounded by a cage of fine platinum wire.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim is :-
In hoods prepared as illuminant appliances for burners, the use of oxide of Thorinum
alone or in admixture with oxides of Zirconium, Lanthanum, Yttrium, Neodymium,
Erbium, Magnesium or Aluminium substantially as herein described.
ABEL & IMKAY,
Agents for the Applicant.