Method of Preparing Dentists' Gold.
Year: 1896

page_text: Date of Application, 28th July, 1896.
Complete Specification Left, 28th Apr., 1897-Accepted, 12th June, 1897
PROVISIONAL SPECIFICATION.
Method of Preparing Dentists' Gold.
We, CHAUNCEY ADELBERT FLOWER, Dentist, and EMMA ADELLA FLOWER, Gentle-
woman, both of 303, Broad Street, New Bethlehem, in the County of Clarion and
State of Pennsylvania, United States of America, do hereby declare the nature of
this invention to be as follows:-
Our invention is in the nature of a novel method of preparing gold for the use of
dentists in filling teeth whereby it can be made to weld or cohere and thereby be
made into a solid filling without the usual aid of a hand, electric, or any other form
of mallet only requiring by an ordinary skilled dentist a slight manipulating pressure
with ordinary plugging instruments to be made into the most beautiful, tenacious, and
duruble contours as fillings in teeth.
In carrying out the method we take any form of dentist's gold either beaten into
sheets, rolled, or made into cylinders or pellets, or in the form of spongy precipitate,
and place it upon mats composed of asbestos or carbon sheets and then introduce it
into an electrical or other form of furnace and heat the gold to about 1562 degrees
Fahrenheit, at which temperature there will be presented upon the surface of the gold
a grey or frosty-like appearance. The gold is then withdrawn from the furnace and
immediately placed in a refrigerator at a temperature of air at or below 35 degrees
Fahrenheit, or in the place thereof it may be plunged into ice water. When cold the
gold is placed on the asbestos pads and put into a leering or annealing furnace and
heated to 220 degrees Fahrenheit, and retained there at such heat for thirty minutes
and gradually allowed to cool. This gives a grade of gold that is semi-cohesive. The
heat is then again raised to 350 degrees Fahrenheit and maintained at that point for
twenty minutes which makes it a good cohesive gold. For extra cohesive properties
the heat is raised to 5 0 degrees Fahrenheit and held there for thirty minutes. The
gold is then cooled and is ready to be weighed and packed in marketable shape.
The gold prepared as above described will cohere under a slight pressure with a
serrated hand plugging instrument in the hands of an ordinary skilled dentist and it
does not require a blow with a mallet as heretofore has been the case and all that is
required with this gold is to add piece to piece, pressing each piece evenly and firmly
one on to the other until the cavity is full, when it will be found to be one solid piece
of gold that can be filed and finished to a good polish the same as with the ordinary.
dentist's gold after a mallet has been used.
The first step of the process of running the gold to a high heat and then cooling
instantly is to make the gold very soft and pliable and which is the opposite effect that
would be the case with steel and other metals of its class.
In gold the granules are formed near the melting point and a sudden chill expands
the granules of gold and it then is soft. When using beaten gold its grains have
been flattened out into thin and long fibres but the hammer has compacted them very
close together. They are however ready to assume their natural granular shape again
as soon as released from their unnatural tension which can only occur at a certain
temperature which is at a point near to melting or about the temperature 1562 degrees
Fahrenheit. Each grain then commences to loosen from its companion preparatory
to assuming its shape and when suddenly chilled the grains are further separated and
the gold is brought into its softest condition with all its small and delicate fibres
loosened from their neighbours and it is then in its best possible condition to be
interwoven with others of a similar character and become attached together again

page_text: and by the least possible pressure to be compacted and held together by cohesive
attraction.
The last heating operation is slightly above the boiling point and serves to evaporate
all moisture and to allow a better cohesion of the fibres which are still soft and too
delicate to handle roughly but as the heat increases the fibres become more compact
and tough and by holding the heat at 350 degrees the fibres become stiff and at the
same time tough and stronger. The time (twenty minutes) during which it is held
at this temperature increases the cohesive properties to its natural limit and a longer
period does not increase it.
When the temperature is carried to the highest point (550 degrees) Fahrenheit,
it further hardens and stiffens the fibres but does not increase the cohesive properties.
The only advantage of this higher temperature is that 'such gold is harder and tougher
"and when filed receives a higher polish than the gold at the three fifty point.
To increase the desired effect of softening the gold and loosening its particles we
sometimes employ an electric current or give to the gold an electric shock or polarity
and for this purpose the gold is plunged after it comes from the annealing or tempering
furnace into a bath of water charged with electricity whereby the fibres or 'ultimato
particles of the gold are better separated and loosened and freed from any oxide and
better adapted to interlacing or cohering when compacted into a filling as will be
hereinafter more fully described. In carrying ont this modification of the invention
we use an apparatus consisting of a pan of zinc which has at its bottom a marginal
flange that is seated upon a non-conducting and insulating base which may be a plate
of glass, or a porcelain or earthen tile, or a plate of hard rubber. Within this pan
is arranged a tray of copper having a woven wire bottom which tray is provided
with handles by which it may be suspended within the pan without touching its sides
or bottom and be conveniently lifted into or. out of the pan by suitable suspending
devices. To the zinc pan is attached the negative pole of a battery and to the tray
is attached the. positive pole of the battery. The, pan now being filled with water,
the gold after it comes from the furnace where it has been heatei to a temperature
of not less than 610 degrees Fahrenheit, is placed in the tray and plunged into the
bath of electrified water which softens the gold, causing its fibres to become loosened
and granular and in a condition to secure greater coherence when compacted -into
fillings. By plunging the gold into the electrified bath not only is the gold changed
physically by the chilling effect but the polarity of the bath aids the ultimate particles
in assuming the form and relation best adapted to coherence and also keeps the surface
clean and bright and in a condition fit for close and permanent unification by the
dental tool. Instead of plunging the gold into an electrified bath of water, we may
simply give to it a polarity or shock from a battery or electrical machine in the open
air which acts to some extent as a cold chilling bath.
Dated this 28th day of July 1896
A. M. & WM. CLARK,
53, Chancery Lane, 'London, Chartered Patent Agents.
Method of Preparing Dentists" Gold.
We, CHAUNOEY ADELBERT FLOWER, Dentist, and EMMA "ADELLA FLOWER, Gentle
woman, both of 303, Broad Street, New Bethlehem, in the County of Clarion and
State of Pennsylvania, United States of America, 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 :-
Our invention is in the nature of a novel method of preparing gold for the use of
dentists in filling teeth, whereby it can be made to weld or cohere:-and thereby: be
made into a solid filling without the usual aid of a hand, electric, or any other form of

page_text: mallet; only requiring by an ordinary skilled dentist a slight manipulating pressure
with ordinary plugging instruments to be made into the most beautiful, tenacious and
durable contours as fillings in teeth.
In carrying out the method we take any form of dentists' gold either beaten into
sheets, rolled, or made into cylinders or pellets, or in the form of spongy precipitate,
and place it upon mats composed of asbestos or carbon sheets and then introduce it
into an electrical or other form of furnace and heat the gold to about 1562° Fahrenheit
at which temperature there will be presented upon the surface of the gold a grey or
frosty-like appearance.
The gold is then withdrawn from the furnace and immediately placed in a
refrigerator at a temperature of air at or below 35° Fahrenheit, or in the place
thereof it may be plunged into ice-water. When cold, the gold is placed on the
asbestos pads and put into a leering or annealing furnace and heated to 220° Fahrenheit
and retained there at such heat for thirty minutes and gradually allowed to cool.
This gives a grade of gold that is semi-cohesive. The heat is then again-raised to
350° Fahrenheit and maintained at that point for twenty, minutes which makes
it a good cohesive gold. For extra cohesive properties, the heat is raised to
550° Fahrenheit and held there for thirty minutes. The gold is then cooled and is
ready to be weighed and packed in marketable shape.
The gold prepared
as above described will cohere under a slight pressure with a
serrated hand plugging instrument in the hands of an ordinary skilled dentist and it
does not require a blow with a mallet as heretofore has been the case, and all that is
required with this gold is to add piece to piece, pressing each piece evenly and firmly
one on to the other until the cavity is full, when it will be found to be one solid piece
of gold that can be filed and finished to a good polish the same as with ordinary
dentists' gold after a mallet has been used. The first step of the process of running
the gold to a high heat and then cooling instantly, is to make the gold very soft and
pliable, and which is the opposite effect that would be the case with steel and other
metals of its class.
In gold the granules are formed near the melting point and a sudden chill expands
the granules of gold and it then is soft. When using beaten gold its grains have
been flattened out into thin and long fibres, but the hammer has compacted them very
close together. They are however ready to assume their natural granular shape again
as soon as released from their unnatural tension, which can only occur at a
certain temperature which is at a point near to melting or about the temperature
1562° Fahrenheit. Each grain then commences to loosen from its companion
preparatory to assuming its shape, and when suddenly chilled the grains are further
separated and the gold is brought into its softest condition with all its small and
delicate fibres loosened from their neighbours, and it is then in its best possible
condition to be interwoven with others of a similar character and become attached
together again, and by the least possible pressure to be compacted and held together
by cohesive attraction.
The last heating operation is slightly above the boiling point and serves to evaporate.
all moisture and to allow a better cohesion of the fibres which are still soft and too
delicate to handle roughly but as the heat increases the fibres become more compact
and tough, and by holding the heat at 350° the fibres become stiff and at the same
time tough and stronger.
The time (twenty minutes) during which it is held at this temperature increases the
cohesive properties to its natural limit, and a longer period does not increase it.
When the temperature is carried to the highest point (550°) Fahrenheit it further
hardens and stiffens the fibres, but does not increase the cohesive properties.
The only advantage of this higher temperature is that such gold is harder and
tougher, and when filed receives a higher polish than the gold at the three fifty point.
To increase the desired effect of softening the gold and loosening its particles, we
sometimes employ an electric current or give to the gold an electric shock or polarity,
and for this purpose the gold is plunged after it comes from the annealing or tempering
furnace into a bath of water charged with electricity whereby the fibres or ultimate

page_text: particles of the gold are better separated and loosened and freed from any oxide and
better adapted for interlacing or cohering when compacted into a filling as will be
hereinafter more fully described.
In carrying out this modification of the invention we use an apparatus similar to
that shown in the accompanying drawing, in which
Figure 1 is a vertical section and
Figure 2 a plan view of the electrical bath.
A is a pan of zine which has at its bottom a marginal flange a that is seated upon a
non-conducting and insulating base B which may be a plate of glass or a porcelain or
-earthern tile, or a plate of hard rubber.
Within this pan is arranged a tray C of copper having a woven wire bottom, which
tray is provided with handles 6 by which it may be suspended within the pan without
touching its sides or bottom, and he conveniently lifted into or out of the pan by
suitable suspending devices. To the zinc pan is attached the negative pole of a
battery D and to the tray C is attached the positive pole of the battery.
The pan now being filled with water, the gold after it comes from the furnace where
it has been heated to a temperature of not less than 600° F. is placed in the tray and
plunged into the bath of electrified water which softens the gold, causing its fibres to
become loosened and granular, and in a condition to secure greater coherence when
compacted into fillings. By plunging the gold into the electrified bath not only is the
gold changed physically by the chilling effect, but the polarity of the bath aids the
ultimate particles in assuming the form and relation best adapted to ccherence, and
also keeps the surface clean and bright and in a condition for close and permanent
unification by the dental tool.
Instead of plunging the gold into an electrified bath of water we may simply give
to it a polarity or shock from a battery or electrical machine in the open air which
acts to some extent as a cold chilling bath.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
-claim is :-
1. The method of preparing gold for dental purposes, consisting in heating it to a
temperature approximating the melting point, to establish its granular form, then
suddenly cooling it to expand the granules and render the gold soft and cohesive, then
again subjecting it to a heat of about 220° Fahrenheit and allowing it to remain at
that temperature for a period substantially as described to render it tough and
*tenacious.
2. The method of preparing gold for dental purposes, consisting in heating it to a
temperature approximating the melting point, to establish its granular form, then
suddenly cooling it to expand the granules and render the gold soft and cohesive, then
again subjecting it to a heat of about 220° Fahrenheit, allowing it to remain at that
temperature for a few minutes and to gradually cool, then running the temperature
up to 350° and afterwards to 550° Fahrenheit, holding it at that for a few minutes and
then allowing it to cool substantially as and for the purpose described.
3. The process of treating gold for the use of dentists which consists in first heating
it as described, and then subjecting it to a cooling effect in an electrified bath
substantially as and for the purpose described.
Dated this 28th day of April 1897
A. M. & WM. CLARK,
53 Chancery Lane, London, Chartered Patent Agents.