Improvements relating to the Preparation of Incandescence Bodies.
Year: 1896

page_text: Date of Application, 13th July, 1896
Complete Specification Left, 20th Aug., 1896-Accepted, 26th Sept., 1896
PROVISIONAL SPECIFICATION.
[Communicated from abroad by F. MEYER & Co., of 15 Scharrenstrasse, Berlin,
'Manufacturers.]
Improvements relating to the Preparation of Incandescence Bodies.
I, RICHARD JULIUS EIFFE, 16-17 Great St. Helens, in the County of London,
Merchant, do hereby declare the nature of this invention to be as follows:-
A number of chemical compounds have been specified for the preparation of
incandescence bodies, which when arbitrarily mixed with one another, and heated in
the non-luminous flame are alleged to emit an intense light.. The inventor has
examined these bodies but has not been able to arrive at a practical result excepting
with the employment of the so-called cerite and ytterite earths. He then directed his
researches to the discovery of mixtures, the physical qualities of which in respect to
resistance to heat and the like enable them to be heated in the non-luminous flame
without volatilisation up to the highest attainable temperature.
He hereby discovered that the oxides of the platinum metals in very finely divided
condition and when exposed to a high temperature are most particularly suitable for
the production of a brilliant light, but it is necessary to make use of them together
with oxides which are known as conveyors of oxygen, such as those of chromium,
manganese, cobalt, vanadium, tungsten (wolframium) and the like.
The required state of most minute subdivision is preferably attained by embedding
the above named salts in non-volatile, refractory oxides, such as those of calcium,
magnesium, aluminium, zirconium, beryllium and the like, or of mixtures thereof.
The following formula may serve as an example of such a preparation :-
Calcic oxide
Zirconia
Rhodium
Vanadium
Cobalt
.26.50%
72.50%
0:50 %
0.20 %
0:30 %
W. P. THOMPSON & CO.,
322, High Holborn, London, W.C., Patent 'Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to the Preparation of Incandescence Bodies.
I, RICHARD JULIUS EIEFE, 16-17 Great. St. Helens, in the County of London,
Merchant, 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:―
For the preparation of incandescence bodies a number of combinations have been
proposed of elements mixed with one another in all manner of ways, generally quite

page_text: arbitrarily and intended to produce the effect of an incandescence light when heated
in the non-luminous flame. Many of these compositions are quite unsuited for the
production of a useful incandescence body, because their composition is diametrically
opposed to the principle which determines the emission of light.
One inventor proposes to coat a bad conductor of heat such as alumina, zirconia, or
the like with a good conductor of heat such as platinum, oxide of copper, iridium,
chromium cobalt, under the impression that the heat of the gas flame would be better
conveyed to the bad conductor of heat underlying the coating which in consequence
of the increase of its temperature would become more luminous. This conclusion is a
scientific error because the property of a good conductor of heat lies in its physical
capability of radiating free heat more quickly than a bad conductor. Consequently,
according to the device in question the bad conductor of heat will have more quickly
removed from it by means of the coating the heat which it possesses, and thereby
become less luminous. With some other patented combinations, on the other hand, it
is practicable to obtain a more or less satisfactory light. Through study of the
physical phenomena presented by incandescence bodies I have been able to discover
underlying principles which condition the production of incandescent light. My
researches have demonstrated the following principle on which the luminosity of
incandescent light depends. The oxides of certain elements are capable, at high
temperatures of taking up oxygen and of yielding the same again, and thus. in the
presence of reducing gases, or the like, of converting themselves into lower oxides,
and on the subsequent access of oxygen again absorbing the same. All these bodies
may be designated by the technical term "oxygen-conveyors." OFor instance, copper
oxide may be reduced at about 800 degrees Centigrade by means of coal gas, even to
metallic copper, oxide of chromium may be reduced to a lower oxide, and so on, and
on the other hand metallic copper, chromium, suboxide, and so forth, if heated at
800 degrees Centigrade in the air will again absorb oxygen, and be reconverted into
normal oxide of copper, and of chromium, and so forth. If small quantities of oxides
of oxygen-conveying bodies in a state of extremely fine subdivision be distributed
throughout larger quantities of refractory (that is to say not oxygen-conveying)
oxides, and the whole be exposed to the outer surface of a non-luminous flame
the above described reactions take place, and an intense light is emitted. In
consequence of the aforesaid reaction and the evolution of oxygen in the nascent state,
a very intense combustion is caused together with a considerable increase in
temperature. Although as already stated certain combinations already patented fulfil
the requirements of the principle above set forth, the inventors not having recognised
the principle on which their empirical experiments were based have omitted to bring
certain other bodies within the range of their studies and patents, the use of which, I
have discovered to be of extreme importance for incandescent lighting. Having
discovered the scientific principle on which the incandescent light depends I proceeded
to ascertain the best available mixture which would be suited to carry the same
practically into effect. Neither zirconia nor alumina nor calcium oxide alone is
capable of resisting flame for more than a short time. All these bodies either soon
fall to powder or are fused into useless masses. Only thorium alone gives good results
throughout as a non-oxygen-conveyor for the preparation of the incandescence bodies
already patented. As the result of my own experiments I have discovered that the
combination of my invention together with the combination set forth below of zirconia
and calcium oxide produces an excellent compound of very good power of resistance
and hardness I feel no doubt that further experiments may prove that from the
elements specified by other inventors or from other bodies such for instance as
beryllium practicable combinations may eventually be founed, but the same, as far as
I am aware, are not discovered up to the present. As conveyors of oxygen, I have
investigated all the elements used by previous patentees and many other substances,
such for instance as nickel, iron, and so forth, as well but I have found that it was
not possible to obtain thereby a perfectly satisfactory intense white light. I have
however by further experiment discovered bodies by means of which the emission of
light is very greatly increased when accurately determined quantities of oxides are

page_text: mixed together and which appear to mutually assist each other in their properties.
For instance, a mixture of rhodium and manganese evolves an almost snow white
light, whereas the former when used alone gives a reddish and the latter a yellowish
light. In the same way palladium with manganese gives a more or less satisfactory
effect. The best combination for this purpose known to me consists of a mixture of
rhodium and ruthenium with vanadium, approximately in the proportions hereinafter
indicated.
Having now fully explained the principle upon which combinations must be made I
give the following formula for the preparation of my improved incandescence body.
From the same, every person skilled in the art will be able to effect the choice and
combination of the requisite salts which are necessary for the manufacture.
Oxide of calcium
Oxide of zirconium
Oxide of vanadium
Oxide of ruthenium
Oxide of rhodium
27.50%
72.30%
-
0.10%
0-05%
0.05%
A solution of the nitrates or other suitable soluble salts of the above bodies is
prepared corresponding to the above formula and the mantles or fabrics saturated with
the same, and prepared for use in the manner well known to those skilled in the
manufacture thereof.
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 :-
1. In the preparation of incandescence bodies, the use of either oxide of rhodium or
oxide of ruthenium or both in combination with oxide of vanadium in extremely
fine division, and diffused throughout a compound of zirconia and calcium oxide,
substantially as above set forth.
2. In the manufacture of incandescence bodies the use of a salt of vanadium alone
or in combination with metallic salts.
3. In the manufacture of incandescence bodies the use of salts of rhodium and
ruthenium together or separately, and with or without other metallic salts.
Dated this 20th day of August 1896
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.