IMPROVEMENTS IN THE TREATMENT OF BONE, VEGETABLE IVORY, AND OTHER POROUS SUBSTANCES, AND IN APPARATUS EMPLOYED THEREIN."
Year: 1877

page_text: LETTERS PATENT to George Hand Smith, of South Kensington, in the County
of Middlesex, Doctor of Medicino, for the Invention of "IMPROVEMENTS IN THE
TREATMENT OF BONE, VEGETABLE IVORY, AND OTHER POROUS SUBSTANCES,
AND IN APPARATUS EMPLOYED THEREIN."
PROVISIONAL SPECIFICATION left by the said George Hand Smith at the
Office of the Commissioners of Patents on the 4th December 1877.
GEORGE HAND SMITH, of South Kensington, in the County of Middlesex, Doctor
of Medicine. "IMPROVEMENTS IN THE TREATMENT OF BONE, VEGETABLE IVORY, AND
OTHER POROUS SUBSTANCES, AND IN APPARATUS EMPLOYED THEREIN."
My Invention relates chiefly to an improved process whereby color, lustre, and
translucency or some of these qualities are imparted to certain substances or are
increased in bodies of a translucent nature.
The Invention is applicable to bone, vegetable ivory, and other porous substances,
but for the purpose of explaining its nature, I shall describe as an example of its
application, the treatment of articles made of vegetable ivory. I provide a vessel
or chamber of a convenient size and shape so constructed as to be gas-tight, and
capable of being heated on its exterior. The vessel is fitted with movable frames
or cylinders of wire gauze, so arranged as that they may be made to revolve at will
without opening the vessel in which the articles to be treated are laid. Into this
vessel there is introduced a mixture of caoutchouc, translucent gum, and gum
resins, or any one or more of these, with bisulphide of carbon or other like volatile
solvents in sufficient quantity to cause the articles placed in the vessel to be sub-
merged in the solution (the supply being controlled by means of a valve or cock).
The bisulphide of carbon or its equivalent, as before mentioned, penetrates the
articles under treatment, and carries in with it the translucent or other mixture.
When the articles have been subjected to the action of the solution for the
requisite period (which will vary with the size of the articles under treatment), a

page_text: sufficient quantity of the solution to reduce the level of the liquid to below that of
the articles is drawn off through a valve or cock at the bottom of the vessel into a
second vessel, so that it may be used again. After the articles have thus been fully
charged with the solution and part of the latter has been drawn off, as above men-
tioned, the frames or cylinders are occasionally revolved, subjecting the surfaces of
the articles to the action of the volatile bisulphide of carbon, gas, or other equivalent
with which the vessel is charged If necessary a gentle heat may be applied to
the exterior of the vessel or chamber. The gas given off from the residue of the
solution left in the vessel or chamber is made available for clearing the surfaces of
the articles from the solution which adheres thereto, as the volatile bisulphide gas
or other equivalent dissolves this solution or compound and gradually renders the
surfaces clean. The remainder of the solution is then drawn off, and heat or a
higher heat, as the caso may be, is applied to the vessel or chamber for a
sufficient period, whereby the bisulphide of carbon or other equivalent remaining
in the articles treated is driven off to be collected in a condensing or other con-
venient vessel.
On removing the articles from the vessel or chamber they will be found if
originally opaque, to have become translucent, or to have acquired some other
imparted quality; and if translucent, to have had their translucency increased
with a higher lustre and greater density.
The articles under treatment may be colored by the process described in the
Provisional Specification filed by inc, with my application for Letters Patent dated
the 29th September 1877, No. 3640, previously to their being subjected to the
improved process, which forms the subject of my present Invention, or color may
be added to the solution before mentioned or otherwise applied to the articles,
previously to or during their treatment by the present process.
When it is desired to impart colour to objects intended to be treated by my
improved process, herein referred to, it will be found advantageous to apply the
colour to the objects beforehand, and to remove by washing or otherwise all excess
of colour from their surfaces before they are introduced into the closed chamber or
vessel, and treated as above described. The solution employed will thereby be
retained comparatively free from any imparted colour.
Although I have described the above mode of carrying my process into practical
operation as being the most simple and effectual the mode of proceeding may in
some respects and in its details be varied.
It will be seen that the employment of my improved process enables me to
manufacture a material of a new character possessing properties of great com-
mercial value.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Hand Smith in the Great Seal Patent Office on the 4th
June 1878.
GEORGE HAND SMITH, of South Kensington, in the County of Middlesex, Doctor
of Medicine. "IMPROVEMENTS IN THE TREATMENT OF BONE, VEGETABLE IVORY, AND
OTHER POROUS SUBSTANCES, AND IN APPARATUS EMPLOYED THEREIN."
My said Invention has reference to the treatment of bone, vegetable ivory, and
other porous substances, and relates chiefly to an improved process and apparatus
whereby color, lustre, and translucency, or some of these qualities are imparted to
certain of these substances and increased in others of a lustrous and translucent
nature.
In carrying out my said process I find it advantageous to employ apparatus
constructed in the manner shewn on the accompanying Drawings, or equivalent
apparatus operating in a similar manner for a like purpose.
In my Drawings I have shewn two modifications of apparatus which will be
practically successful, and the description of which will enable any further modi-
fications to be made by persons skilled in treating substances analagous to those
herein referred, or in using apparatus of the character hercin-after described in
order to adapt the apparatus to the special requirements of particular cases.
Figure 1 of my Drawings represent a side clevation of an apparatus constructed
according to one modification, used by me for the purpose of carrying out my
process. Figure 2 is a corresponding plan, aud Figure 3 a transverse vertical section
of the same, both corresponding to Figure 1.
Figures 4, 5, and 6 are similar views to Figures 1, 2, and 3, illustrating another
modification.
The same letters indicate corresponding parts in all the Figures.
A is a vessel or chamber (herein-after designated the holder) made of tinned iron,
copper, or other suitable material, and of a convenient size and shape for the
reception and treatment of the articles to be operated upon. This holder is so
constructed as to be gas-tight, and capable of being heated on its exterior by means
of a gas burner B or otherwise. It is connected by a pipe C with another vessel D
(herein-after designated the reservoir), whence the holder A is charged, as herein-
after explained, and the said reservoir is also capable of being heated either by
The holder A is
means of a gas burner E or in any other convenient manner.
provided with a man-hole, closed by a door or cover F, and with a guage G for indi-
cating pressure, and a safety valve H or a cock for the relief of any excess of
pressure, and also with a pipo I leading to or capable of being connected with a
condenser. The pipe I is fitted with a cock a, and similar cocks b, b³, are provided
in the pipe C, communicating between the holder A and the reservoir D.
In the interior of the holder A I arrange one or more frames or cylinders K of
wire gauze or perforated metal, and which are intended to contain the articles to be
operated upon. The said articles being introduced into the frame or frames through
the man-hole at F and through a door or doors c, with which the frames are pro-
vided. When necessary any convenient means of holding the articles may be
employed, such as shelves, or, when required, separate holders or frames.
It is requisite at a certain stage of the operation that the articles under treatment
should be so moved or tilted or inclined as to enable the mixtures, herein-after
mentioned, to be drained from them. Provision is made for enabling this to be
effected, either by mounting the frame or frames K in the holder A, so that they
shall be free to rotate, as in the arrangement shewn in Figures 1, 2, and 3, or by
making the holder itself moveable on axes, as in the modification illustrated in
Figures 4, 5, and 6. In the former case (Figures 1, 2, and 3) the frames are
operated from the exterior at d by means of bevel gearing L and spur gearing H,
whilst in the modification shewn in Figures 4, 5, and 6, the holder A is mounted

page_text: on axes e, e, in a gimbal M, which in its turn is free to rotate on axes f, f, carried
in bearings in the framing N of the apparatus.
In carrying out my process with the aid of apparatus, such, for example, as that
shewn in Figures 1, 2, and 3, or in Figures 4, 5, and 6, I proceed in the following
manner, videlicit:-The cocks b, 61, in the connecting pipe C being closed I intro-
duce into the reservoir D through the funnel O a mixture (herein-after termed the
agent or converting agent) of translucent or transparent materials, such as gum,
gum resins, caoutchouc, or any or more of these or similar materials combined
with bisulphate of carbon or other like volatile solvents, such as ether, chloroform,
or other matters possessing liko desired properties. I then close the cock a with
which the said funnel is provided, and I place the articles to be operated upon
the frame or frames K of the holder A, by introducing them through the man-hole
at F and through the cover door or doors c, and then close the said doors and the
man-hole doo F. I then open the cocks b, b', and, if necessary, apply heat to the
under side of the reservoir D so as to cause the agent to pass from the reservoir D
into the holder A, whereby the articles contained in the frame or frames K of the
holder will be submerged in the agent, and the cocks b, b¹, are then closed.
in
The bisulphide of carbon or its equivalent as before mentioned penetrates the
articles under treatment, and carries in with it the translucent or other material with
which it is combined This treatment may be carried out at the ordinary temper-1
ature, especially when bisulphide of carbon is used, or when desired it may be
accelerated and facilitated by the application of heat, the vaporized bisulphide or its
equivalent being confined so as to generate pressure and acelerate the action of the
bisulphide or equivalent mixture.
In some cases the agent may be first made thin to assist penetration, and afterwards
thickened by adding more gum or its equivalent, so as to increase translucency and
lustre.
When the articles have been subjected to the action of the agent for the requisite
period (which will vary according to the size of the articles under treatment, and
the mixtures used and the temperature applied) a sufficient quantity of the agent to
reduce the level of the liquid to below that of the articles operated upon, is drawn
off' either by gravitation, or by means of a pump or of the pressure of the vapors
evolved into the reservoir D, so that the said agent may be used again. After the
articles have thus been fully charged with the agent, and a portion of the latter has
been drawn off from the holder A as above mentioned, the articles are if necessary
tilted or inclined, or are moved in any convenient manner to admit of the excess
of the agent upon their surfaces being drained off, and to facilitate the action of
the bisulphide of carbon or its equivalent, the latter becomes vaporized from tho
residue of the agent remaining in the holder, and is thus made available for
cleansing the surfaces of the said articles by dissolving the excess of the gum or
its equivalent adhering to them, and enabling it to flow off.
The tilting or inclining or otherwise moving the position of the articles for this
purpose is effected in the case of the arrangement of apparatus shewn in Figures 1,
2, and 3, by imparting rotary motion to the frames K in the manner herein-before
described, and in the case of the modification illustrated by Figures 4, 5, and 6, by
turning the holder A. itself upon its axis, having previously disconnected the pipe C
at b¹
In Figure 4 I have represented in dotted lines the holder A as thus inclined, and
in Figure 6 I have represented in dotted lines the holder A in another inclined
position, the object being to turn the articles into various successive positions, so as
to facilitate the separation of the excess of the agent adhering to their surfaces,
and of the action thereon of the bisulphide of carbon, or its equivalent employed.
If necessary a gentle heat may be applied to the under side of the holder for the
purpose of facilitating this stage of the process, provided that sufficient heat is not
retained when heat is employed in the first stage as above indicated. The remainder
of the agent is then drawn off into the reservoir D.
In the case of the apparatus shewn in Figures 4, 5, and 6, the pipe C should be

page_text: previously connected at b. A gentle heat is continued to be applied to the holder A
for a sufficient period, whereby the bisulphide of carbon or its equivalent
remaining in the articles treated is driven off through the pipe I into a condenser or
other convenient vessel for further use.
In some cases the articles after having been treated with the converting agent and
cleansed may be removed and dried in a drying chamber.
The employment of heat which is advantageous in assisting the action of the
converting agent, and the cleansing of the articles may be some cases be dispensed
with. For instance, when bisulphide of carbon is the solvent used the operations
may be conducted at ordinary temperatures, and when heat is used to accelerate them
only low heats should be used, as will be readily understood by those who are
familiar with the character of this solvent.
.
In some cases fresh bisulphide of carbon or its equivalent may be introduced
into the holder for the purpose of washing and cleansing the articles in the cleansing
stage, or the cleansing may be effected by immersion in the bisulphide of carbon or
its equivalent, with the addition of a small quantity of gum if necessary. It will
thus be understood that bisulphide of carbon will in all cases be found a very
efficient agent for effecting or completing the cleansing operation.
After cleansing and drying slowly, so as not to disturb the materials taken up,
other or other solvent may be advantageously used to remove any film if any be
present. This may in some cases be effected by hand; or the articles may in soine
cases be finished by rubbing then with a revolving brush or buffer.
In some cases it may be found advantageous, say, for example, when resin is
employed as a constituent of the mixture used as the converting agent to improve
the finish of the articles after the treatment indicated. This may be done by im-
inersion for a short period in a solution of caoutchouc in bisulphide of carbon or
of gun lac in alcohol, or in some other analogous solution or liquid.
If desirable paraffin may be employed in place of bisulphide of carbon and gums
in the first stage of the process where the articles are impregnated with the con-
verting agent. The articles after the superfluous paraffin has been removed or
drained off are allowed to cool, and are then treated with solutions of gum lac, or
caoutchouc, or other like gums used to complete the process.
It order to effect this conveniently, additional reservoirs containing different
solutions of the gums, or their equivalents employed, are provided, the same
being so arranged as to be capable of being placed in communication with the
holder by means of suitable pipes from the bottom of the respective vessels fitted
with cocks and union joints in order that they may be filled or emptied at will, and
disconnected when motion is to be given to the holder; or any other convenient
apparatus may be employed for effecting the desired object.
When articles have been treated in the manner herein-before described, on re-
moving then from the holder they will be found, if originally opaque, to have
become translucent, or to have acquired some other imparted quality, such as increased
hardness or density, and if translucency, to have had their translucency increased
with a higher lustre and greater density.
The articles under treatment may be colored by the process described in the
Specifiction to Letters Patent granted to me, dated the 29th September, 1877,
No. 3640, previously to their being subjected to the improved process, which forms
the subject of my present Invention, or color may be added to the solution before
mentioned, or otherwise applied or supplied to the articles previously to or during
their treatment by the present process.
When it is desired to impart colour to articles intended to be treated by my im-
proved process, herein referred to, it will be found advantageous to apply the colour
to the articles before hand, and to remove by washing or otherwise all excess of
colour from their surfaces before they are introduced into the holder, and treated as
above described. The solution employed will thereby be retained comparatively
free from any imparted colour.
Although I have described the above method of carrying my process into practical

page_text: operation, as being the most simple and effectual mode of proceeding with which I
am acquainted, it will be obvious that it may in some respects be varied, and that
the details of the operations and apparatus employed may be readily modified, as ex-
perience in conducting the operations may shew to be necessary.
It will be seen that the employment of my improved process enables me to manu-
facture a material of a new character, possessing properties of great commercial
value.
Having now described and particularly ascertained the nature of my said Inven-
tion, and the manner in which the same is or may be used or carried into effect, I
would observe in conclusion that what I consider to be novel and original, and
therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,―
First. Effecting the treatment of bone, vegetable ivory, and other porous
substances by the employment of a converting agent or agents, substantially as and
for the purposes herein set forth.
Second. The use for the purpose of treating porous substances, in the manner
above set forth, of apparatus constructed and arranged so as to operate sub-
stantially in the manner herein-before described.
Third. Effecting the cleansing of the articles or materials operated upon, by the
process herein-before referred to, by using vaporised solvents to remove the superfluous
converting agent, substantially in the manner herein-before described.
Fourth. The manufacture of articles of the new material produced by the process,
substantially as herein described.
In witness whereof, I, the said George Hand Smith, have to this my Specifica-
tion set my hand and seal, the First day of June, One thousand eight
hundred and seventy-eight.