Year: 1896

page_text: Dale of Application, 29th Sept., 1896
Complete Specification Left, 14th June, 1897-Accepted, 24th July, 1897
A communication from GEORGE MILTON BAIR, of Hanover, County of York, State of
Pennsylvania, U.S.A., General Business Agent, and CALVIN WESTLEY REAM, of
Reading, County of Berks, State of Pennsylvania, U.S.A., General Business
Agent.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden in the County of Middlesex,
Chartered Patent Agent do hereby declare the nature of this invention to be as
follows:-
The object of the invention is to present a ready and efficient substitute for the
grandular carbon now employed in many forms of telephones.
The invention consists in a telephone electrode, or microphonic element, of platinum
having its conductivity lowered.
Heretofore platinum has been tried as an electrode, either in the form of bare pellets
of the compact metal or as sponge platinum, but, in such condition, has been found of
too high conductivity for efficient use.
To present platinum in the form requisite for the present invention take particles
of any suitable substance and deposit thereon by electro-deposition platinum-black; or
take compact platinum such as platinum wire or take platinum sponge, divide into small
pieces and convert the surface into platinum-black; or take platinum-black agglomerate
it in to a mass and divide this into granules or buttons; or take finely-divided platinum
and treat this with a solution of silver-nitrate or chloride and then subject to the
action of light.
One method for depositing platinum-black electrolytically is as follows;-
Take a suitable vessel having, near its bottom, a plate of metal such as silver or
platinum, connected with the positive pole of a battery, and, above this plate, a tray
inade of fine wire, closely woven and connected with the negative pole of the
battery, and upon this tray place the platinum or other metal say in granules, upon
which the platinum-black is to be deposited. Now, fill the vessel with a sufficient
quantity of a weakened solution of chloride of platinum to cover the tray and its
contents. The current passes from the positive pole of the battery to the plate in the
bottom of the vessel thence upwards through the solution, decomposing it, and
precipitating the platinum held in suspension therein upon the surface of the granules
in the form of platinum-black; it being understood that the depth of the deposit will
be determined by the length of time the current is allowed to pass through the
solution. When the required deposit is obtained the tray is removed from the
solution and its contents being thereupon washed and dried will be ready for use.
One method for converting the surface of the platinum into platinum-black is as
follows:-
Take aqua regia and into this place the platinum say in granules. When the acid
has acted a sufficient time on the metal add to the acid an alkali, and a suitable
reducing agent such as alcohol. The result will be platinum having its surface
covered with platinum-black produced from the metal itself.

page_text: In its finely comminuted state either as spongy platinum having its surface covered
with platinum-black or as platinum black platinum possesses a remarkable power of
absorbing and condensing gases and absorbing moisture and to this may possibly be
ascribed the efficiency of the action of some forms of the new substitute for
carbon.
It is found by experiment that by the employment of platinum in the form above
described distincter articulation is obtained and there will be no break or slur, no
matter how sudden or loud may be the projected sound; and a marked advantage of
the use of the product is that it does not pack; furthermore in use, a much smaller
quantity than of carbon is necessary.
One manner of agglomerating platinum-black into a suitable mass is as
follows:-
Mix platinum-black with a rubber cement made by dissolving rubber in bi-sulphide
of carbon the usual proportion of rubber to the bi-sulphide of carbon being about
one-thirtieth more or less, by weight, of the rubber to the carbon bi-sulphide and
the quantity of platinum-black to the cement being about four to eight times the
amount of platinum-black more or less in bulk to the bulk of the rubber, only so the
proper purpose is effected which is to get a strongly coherent mass of platinumn-black
without too much of other substance therewith.
After mixing the mass is dried and thereafter subjected to heat sufficient to render
the whole properly brittle aud non-elastic, whereupon it is broken up into small
particles.
Instead of granulating the mass this may be formed into pieces or buttons suitable
for the electrodes themselves.
To lower the conductivity of platinum with silver-nitrate make a solution of silver-
nitrate of the strength say of one drachm of nitrate to an ounce of water and into this
as a bath place the comminuted platinum. Leave the platinum in this bath for say,
ten minutes, and thereafter take out and place, it upon bibulous paper. Then subject
it to a suitable heat to effect the rough drying without overheating and thereafter
expose it to sunlight for say an hour or more the result being the formation of a
reduced silver salt on the surface.
A
To effect the desired result with silver chloride the procedure is substantially
the same the effect of the light however being to turn the platinum darker.
suitable solution of silver-chloride may be readily prepared from the bath of the
nitrate by adding a solution of chloride of sodium or sal-ammoniac in excess to the
bath thereby the silver chloride formed at first is dissolved.
Dated this 28th day of September 1896
BOULT & WADE,
Agents for the Applicant.
Improvements in or relating to Telephones.
A communication from GEORGE MILTON BAIR, of Hanover, County of York, State of
Pennsylvania, United States of America, General Business Agent, and CALVIN
WESTLEY REAM, of Reading, County of Berks, State of Pennsylvania, U.S.A.,
General Business Agent.
I, ALFRED JULIUS BOULT, of 111 Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, 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 :-

page_text: The object of this invention is to present a ready and efficient substitute for the
granular carbon now employed in many forms of telephones.
The invention consists in a telephone electrode, or microphonic element, of platinum
having its conductivity lowered.
Heretofore, platinuin has been tried as an electrode either in the form of bare
pellets of the compact metal, or as sponge-platinum, but in such conditions, has been
found of too high conductivity for efficient use.
To present platinum in the form requisite for the present invention, take particles
of any suitable substance, and deposit thereon, by electro-deposition, platinum-black;
or take compact platinum, such as platinum wire, or take platinum sponge, divide into
small pieces, and convert the surface into platinum-black; or take platinum black,
agglomerate it into a mass and divide this into granules or buttons; or take finely-
divided platinum and treat this with a solution of silver-nitrate or chloride and then
subject to the action of light.
One method for depositing platinum-black electrolytically is as follows:--Take a
suitable vessel having, near its bottom, a plate of metal, such as silver or platinum
connected with the positive pole of a battery, and above this plate, a tray made of
fine wire, closely woven, and connected with the negative pole of the battery, and
upon this tray, place the platinum or other metal, say, in granules, upon which the
platinum-black is to be deposited. Now, fill the vessel with a sufficient quantity of a
weakened solution of chloride of platinum to cover the tray and its contents. The
current passes from the positive pole of the battery to the plate in the bottom of the
vessel, thence upwards through the solution, decomposing it and precipitating the
platinum, held in suspension therein, upon the surface of the granules in the form of
platinum-black; it being understood that the depth of the deposit will be determined
by the length of time the current is allowed to pass through the solution. When the
required deposit is obtained, the tray is removed from the solution, and its contents.
being thereupon washed and dried, will be ready for use.
One method for converting the surface of the platinum into platinum-black is as
follows: Take aqua regia, and into this, place the platinum, say in granules. When
the acid has acted a sufficient time on the metal, add to the acid an alkali, and a
suitable reducing agent, such as alcohol. The result will be platinum having its
surface covered with platinum-black produced from the metal itself.
In its finely comininuted state, either as spongy platinum having its surface covered
with platinum-black, or as platinum-black, platinum possesses a remarkable power of
absorbing and condensing gases and absorbing moisture, and to this may possibly be
ascribed the efficiency of the action of some forms of the new substitute for
carbon.
It is found by experiment that, by the employment of platinum in the form above
described, distincter articulation is obtained, and there will be no break or slur, no
matter how sudden or loud may be the projected sound; and a marked advantage of
the use of the product is that it does not pack; furthermore, in use, a much smaller
quantity than of carbon is necessary.
One manner of agglomerating platinum-black into a suitable mass is as
follows:-
Mix platinum-black with a rubber cement made by dissolving rubber in bi-sulphide
of carbon, the usual proportion of rubber to the bi-sulphide of carbon being about
one-thirtieth more or less, by weight, of the rubber to the carbon bi-sulphide, and the
quantity of platinum-black to the cement being about four to eight times the amount
of platinum-black, more or less, in bulk to the bulk of the rubber, only so the proper
purpose is effected, which is to get a strongly coherent mass of platinumn-black without
too much of other substance therewith. After mixing the mass is dried and, thereafter,
subjected to heat sufficient to render the whole properly brittle and non-elastic, where-
upon it is broken up into small particles.
Instead of granulating the mass, this may be formed into pieces or buttons suitable
for the electrodes themselves.
To lower the conductivity of platinum with silver nitrate make a solution of silver-

page_text: nitrate of the strength, say, of one drachm of nitrate to an ounce of water, and, into
this as a bath, place the comminuted platinum. Leave the platinum, in this bath,
for, say, ten minutes, and thereafter take out and place it upon bibulous paper. The
subject it to a suitable heat to effect thorough drying without overheating, and,
thereafter, expose it to sunlight, for say, an hour or more, the result being the
formation of a reduced silver salt on the surface.
To effect the desired result with silver-chloride the procedure is substantially the
same, the effect of the light, however, being to turn the platinum darker. A
suitable solution of silver chloride may be readily prepared from the bath of the
nitrate by adding a solution of chloride of sodium or sal-ammoniac in excess to the
bath, whereby the silver chloride formed at first is dissolved.
Having now particularly described and ascertained the nature of this said inven-
tion as communicated to me by my foreign correspondents, and in what manner the
same is to be performed, I declare that what I claim is:-
1. A substance for use at telephone electrodes as a substitute for carbon, comprising
platinum having its conductivity lowered.
2. A telephone electrode comprising platinum-black.
3. A substitute for carbon at telephone electrodes comprising a substance having
its surface covered with platinum-black.
4. A microphonic element comprising a granular substance having its surface
covered with platinum-black.
5. A microphonic element comprising granular, finely divided, or comminuted
metal having its surface covered with platinum-black.
6. A microphonic element comprising granular, finely-divided, or comminuted
platinum having its surface covered with platinum black.
7. A substance for use at telephone electrodes, comprising platinum-black in an
agglomerate mass.
8. A substance for use at telephone electrodes, comprising platinum-black in
granular or free form.
9. A substance for use at telephone electrodes, comprising granular platinum
having its surface covered with a reduced silver salt.
Dated this 14th day of June 1897.
BOULT & WADE,
Agents for the Applicant.