IMPROVEMENTS IN UTILIZING A CERTAIN DESCRIPTION OF CLAY, AND A SUBSTANCE USUALLY POUND THERE- WITH
Year: 1867

page_text: LETTERS PATENT to Alexander McDougall, of Manchester, in the County
of Lancaster, Chemist, for the Invention of "IMPROVEMENTS IN UTILIZING
A CERTAIN DESCRIPTION OF CLAY, AND A SUBSTANCE USUALLY POUND THERE-
WITH
Sealed the 23rd August 1867, and dated the 27th February 1867.
PROVISIONAL SPECIFICATION left by the said Alexander McDougall
at the Office of the Commissioners of Patents, with his Petition, on the
27th February 1867.
I, ALEXANDER MCDOUGALL, of Manchester, in the County of Lancaster,
Chemist, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN UTILIZING A CERTAIN DESCRIPTION OF CLAY, AND A SUBSTANCE USUALLY
FOUND THEREWITH," to be as follows:-
My Invention consists in the utilization of a substance called by miners
"blue clay" or "chanel," which, when found in their workings, is cast to the
spoil bank as useless. I have ascertained that this substance is a mixture of
clay and crystals of iron pyrites or bisulphide of iron, and I find that I can
separate these substances by washing in water so as to detach the clay from
the bisulphide, which, being the heavier, subsides while the clay remains longer
in suspension. The water is made to flow through a series of vessels, the
bisulphide being deposited in the first while the clay subsides in the more
remote. According to another plan I dry the whole substance and separate

page_text: the component parts by agitation or winnowing, thereby allowing them to
assume positions according to their respective specific gravities. I find that
the bisulphide thus obtained can be beneficially employed in the manufacture
of sulphuric acid and other preparations of sulphur in the ordinary manner,
and the clay (which while mixed as found was useless) becomes when
separated available for several purposes to which clay is applied, especially for
the manufacture of sulphate of alumina which may then be used for the
production of alum. It may also be used as fire-clay or for the manufacture
of bricks.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alexander McDougall in the Great Seal Patent Office on
the 27th August 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MCDOUGALL, of Manchester, in the County of Lancaster, Chemist,' send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of February, in the year of our
Lord One thousand eight hundred and sixty-seven, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Alexander McDougall, Her special license that I, the said Alexander
McDougall, my executors, administrators, and assigns, or such others as I,
the said Alexander McDougall, my 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, should 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." In-
PROVEMENTS IN UTILIZING A CERTAIN DESCRIPTION OF CLAY, AND A SUBSTANCE
USUALLY FOUND THEREWITH," upon the condition, amongst others, that I,
the said Alexander McDougall, by an instrument in writing under my
hand and seal, 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.
NOW KNOW YE, that I, the said Alexander McDougall, do hereby
declare the nature of my said Invention, and in what manner the same is to be

page_text: performed, to be particularly described and ascertained in and by the following
statement (that is to say):-
My Invention consists in the utilization of a substance called by miners
"blue clay" or "chanel," and which, when found in their workings, is cast to
the spoil bank as useless. I have ascertained that this substance is mainly a
mixture of clay and crystals of iron pyrites or bisulphide of iron, there being,
however, occasionally a certain proportion of spar, and I find that I can
separate these substances so that the bisulphide can be beneficially employed
in the manufacture of sulphuric acid and other preparations of sulphur, and
the clay becomes when separated available for several purposes to which clay
is applied, especially for the manufacture of sulphate of alumina, which may
then be used for the production of alum or for other ordinary purposes. It
may also be used as fire-clay or for the manufacture of bricks.
In carrying out my Invention the course pursued will vary in some measure
according to the condition of the clay, for in some seams thereof it is found
in a softer state than in others, but it usually consists of plastic portions
combined with others of a harder character. Taking the clay as it is dug I
throw it upon a grid placed within a vessel, and cause water to fall upon the
mass, a vibratory motion being at the same time imparted to the grid, and
rakes or agitators may at the same time act upon the material, the object
being to expose it as much as possible to the action of the water, so that the
clay may be washed through the grid. If the clay is originally in a soft state
this operation may be sufficient to wash it from the bisulphide, which being
thus detached and being the heavier body sinks to the bottom of the vessel,
while the clay remains longer in suspension. The fluid is then caused to pass
through a series of vessels or pits and is gradually deposited, leaving the
bisulphide in the first or other vessel at the cominencing end of the series.
In some cases, however, the agitation in the first vessel may be repeated upon
a grid in another vessel, the workman removing it by a spade from the one grid
to the other, in that case the second grid may be furnished with bars or wires
sufficiently close together to arrest the bisulphide, so that it may not, as in the
first-mentioned case, pass into the fluid. If the material be in a condition to
resist the action of simple washing I in the first place submit it to the
action of rollers or other mechanical apparatus, by which it may be dis-
integrated, and then treat it with water as above mentioned. Rollers similar
to those which are called mortar mills may be used, and during this, rolling
water may be caused to flow through the pan. The clay and bisulphide
having been separated may be used for the purposes.above mentioned, or for
others to which they are ordinarily applied.

page_text: I have above spoken of separating the bisulphide from the clay, I do not,
however, wish it to be understood that a complete separation is necessary, as
the presence of some remaining clay would only be prejudicial in as much
as the cost of transport would be increased, and that of subsequent manu-
facture.
Having thus described and ascertained the nature of my said Invention,
and the manner in which the same is to be performed, I desire it to be under-
stood that I do not limit myself to the apparatus above described, but claim
as secured to me under the above in part recited Letters Patent, the utilization
of the substance above mentioned by separating the clay and other materials
from the bisulphide, or substantially so.
In witness whereof, I, the said Alexander M'Dougall, have hereunto set
my hand and seal, this Twenty-sixth day of August, in the year of our
Lord One thousand eight hundred and sixty-seven.