IMPROVEMENTS IN THE PREPARATION OF A DECOLOURISING MATERIAL SUITABLE FOR THE TREATMENT OF ACID, ALKALINE, AND NEUTRAL SOLUTIONS
Year: 1856

page_text: LETTERS PATENT to John Stenhouse, of 15, Upper Barnsbury Street,
Islington, for the Invention of "IMPROVEMENTS IN THE PREPARATION OF A
DECOLOURISING MATERIAL SUITABLE FOR THE TREATMENT OF ACID, ALKALINE,
AND NEUTRAL SOLUTIONS."
Sealed the 12th September 1856, and dated the 12th June 1856.
PROVISIONAL SPECIFICATION left by the said John Stenhouse at the
Office of the Commissioners of Patents, with, his Petition, on the
12th June 1856...
I, JOHN STENHOUSE, of 15, Upper Barnsbury Street, Islington, do hereby.
declare the nature of the Invention for "IMPROVEMENTS IN THE PREPARATION
OF A DECOLOURISING MATERIAL SUITABLE FOR THE TREATMENT OF ACID, ALKALINE;
AND NEUTRAL SOLUTIONS," to be as follows:-
My Invention consists in producing a highly porous vegetable charcoal,
capable of being employed as a decolourising agent in neutral alkaline and
strongly acid solutions; it, may, therefore be used as a substitute in neutral
and alkaline solutions for common bone black, and in acid solutions for what
is called purified animal charcoal; purified animal charcoal, as is well known,
consists of the porous charcoal, which is obtained by digesting, bone or ivory
black in an excess of hydrochloric acid, till all the lime salts, consisting of car-
bonate and phosphate of lime, contained in the bone black, are dissolved out, and
removed by edulcoration with water. The way in which I produce my porous.
vegetable charcoal is chiefly as follows:-I forn a very intimate mixture of.

page_text: either bydrate of lime, unslacked line in the state of the finest powder, calcined
magnesia, or the light subcarbonate of magnesia of the shops, with certain
vegetable substances, such as maize, wheat, and other kinds of flour, common
resin, or colophonium, pitch, wood tar, asphalte, or bitumen, coal tar, and coal
tar pitch. This mixture of lime or magnesia and vegetable matter is then
heated to redness in close vessels, that is, in ordinary covered crucibles, or in
cast-iron retorts, until the vegetable matter is entirely carbonised. The
mixture, when cold; is then digested with hydrochloric or sulphuric acids,
according as lime or magnesia has been employed, and repeatedly edulcorated
with water on a filter until everything soluble has been removed. The porous
charcoal remaining on the filter is the decolourising agent.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Stenhouse in the Great Seal Patent Office on the
5th December 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
STENHOUSE, of 15, Upper Barnsbury Street, Islington, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of June, in the year of our Lord Ono
thousand eight hundred and fifty-six, in the nineteenth year of Her reign
did, for Herself; Her beirs and successors, give and grant unto me, the said
John Stenhouse, Her special licence that I, the said John Stenhouse, my
executors, administrators, and assigns, or such others as I; the said John
Stenhouse, iny executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at, all times thereafter during
the term therein expressed, shoukl and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE
PREPARATION OF A DECOLORIZING MATERIAL SUITABLE FOR THE TREATMENT; OF ACID,
ALKALINE, AND NEUTRAL SOLUTIONS," upon the condition (amongst others). that
I; the said John. Stenhouse, my exécutors or administrators, by an instrument
in writing under my, or their, or one of their hands and seals, should particularly,
describe and ascertain the nature of the said. Invention, and in what manner the
same. was to be performed, and cause the same to be filed in the Great Seal;
Patent Office within six calendar months next, and immediately after the:
date of the said Letters, Patent:

page_text: NOW KNOW YE, that I the said John Stenhouse, do hereby declare
the nature of the said Invention, and in what manner the same is to bo
performed, to be particularly described and ascertained-in and by the following
statement thereof, that is to say:
My Invention .consists in producing a highly porous vegetable charcoal,
capable of being employed as a decolorizing agent. in neutral. alkaline and
istrongly acid solutions; it may, therefore, be used as a substitute in neutral
and alkaline solutions for common bone black, and in acid solutions for what is
called purified animal charcoal; purified animal charcoal, as is well known,
consists of the porous charcoal, which is obtained by digesting bone or ivory
black in an excess of hydrochloric acid, till all the lime salts, consisting of
carbonate and phosplíate of lime, contained in the bone black, are dissolved out,
and removed by edulcoration with water. The way in. which I produce my
porous vegetable charcoal is chiefly. as follows:-I form a very intimate mixture
of either hydrate of lime, unslacked lime in the state of the finest powder,
calcined magnesia, or the light subcarbonate of magnesia of the shops, with
certain vegetable substances, such as maize, wheat, and other kinds of flour,
common resin, or calophonium, pitch, wood tar, asphalte, or bitumen, coal tar,
and coal tar pitch. This mixture of lime or magnesia. and vegetable-matter-is
then heated to redness in close vessels, that is, in ordinary covered crucibles, or
in cast-iron retorts, until the vegetable matter is entirely carbonized. The
mixture when cold is then digested with hydrochloric or sulphuric acids,
according as lime or magnesia has been employed, and repeatedly edulcorated
with water on a filter until everything soluble has been removed. The porous
charcoal. remaining on the filter is the decolorizing agent.
a
Having thus given general description of my process, I will now proceed
to narrate the special details required to be attended to for carrying it.out
successfully. If, for example, I employ hydrate of lime and coal tar pitch
and coal tar, my mode of proceeding is the following:-I take one pound by
weight of coal tar pitch, and gently heat it in an iron pot till it melts; I then
add two pounds of fluid coal tar and mix the liquids; seven pounds of hydrate
of lime in very fine powder are next gradually stirred into the mass, which
soon becomes thick and pasty. It is then gently roasted, the stirring being
kept up during the whole time till it is reduced to the state of very fine
powder. The great object of the stirring and roasting is to incorporate the
lime with the vegetable matter as intimately as possible. The dark colored
powder obtained in this way is then introduced into ordinary covered crucibles
or iron retorts, and is ignited until the vegetable matter is entirely carbonized.
The mixture when cold is then digested with dilute hydrochloric acid, washed

page_text: .by decantation, thrown upon a filter, and again washed by, decantation thrown
upon a filter and again washed until everything soluble is removed. The
porous charcoal remaining on the filter is the decolorizing agent.
I do not confine myself strictly to the precise quantities of coal tar pitch,
coal tar, and hydrate of lime, mentioned above, for very good decolorising
charcoal may be made by employing variable quantities of these substances.
As already stated, I sometimes likewise employ quick lime in powder instead
of hydrate of lime; I occasionally also employ calcined magnesia, or the light
subcarbonate of magnesia of the shops, with certain vegetable substances, such
as maize, wheat, and other kinds of flour; common resin, or calophonium, pitch,
wood tar, asphalte, or bitumen.
In witness. whereof, I, the said John Stenhouse, have hereunto set my
hand and seal, this Eleventh day of November, in the year of our Lord
One thousand eight hundred and fifty-six.
Witness,
S. CARPMAEL.
JOHN STENHOUSE. (L.S.)