IMPROVEMENTS IN THE MANUFACTURE OF PEARL- HARDENING, WHITE OF BABYTA, AND PRECIPITATED SULPHATE OF LIKE, AS WELL AS OF SUBSTITUTES FOR THISE
Year: 1871

page_text: LETTERS PATENT to Joseph Theodore Dann, of 14, Gloucester Place,
Cowley Road, Brixton, in the County of Surrey, Civil Engineer, for
the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF PEARL-
HARDENING, WHITE OF BABYTA, AND PRECIPITATED SULPHATE OF LIKE, AS
WELL AS OF SUBSTITUTES FOR THISE."-A communication from abroad
by Wilhelm Ahrens, residing at Hamburg, in the Empire of
Germany.
COMPLETE SPECIFICATION filed by the said Joseph Theodore Dann
at the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 25th August 1871, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
THEODORE DANN, of 14, Gloucester Place, Cowley Road, Brixton, in
the County of Surrey, Civil Engineer, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS
IN THE MANUFACTURE OF PEARL-HARDENING, WHITE OF BARYTA, AND PRECIPI–

page_text: '
TATED SULPHATE OF LIME, AS WELL AS OF SUBSTITUTES FOR THESE," and have
petitioned Her Majesty to grant unto me, my executors, administrators,
and assigns, Her Royal Letters Patent for the same, and have made
solemn Declaration that the same is a communication to me from abroad.
by Wilhelm Abrens, a person resident at Hamburg, in the Empire of 5
Germany.
.
NOW KNOW YE, that I, the said Joseph Theodore Dann, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed, in and by the following 1
statement :—
:
of
Instead of preparing white of baryta or blanc-fixe according to any
the methods at present in use, I prefer to add a solution of sulphate of
magnesia, derived from raw sulphate of magnesia, commonly called
kicserit, or of Epsom salt, to a solution of muriate of baryta, nitrate of 1
baryta, or other soluble salts of baryta, in suitable proportion. By
preference I use muriate of baryta in the precipitated solution, and the.
then remaining muriate of magnesia I utilize by employing it either
for preparing cements or artificial marble, for obtaining muriatic acid.
or caustic magnesia, for dressing spun fabrics, or for preparing muriate 2
of lime or hydrate of magnesia. The muriate of lime thus obtained I
préfer to use again in the preparation of muriate of baryta, in the
following manner, that is to say:-I precipitate the muriate of magnesia
by adding caustic lime thereto, so as to obtain muriate of lime, from
which I prepare muriate of baryta according to the methods generally 2
in use, and this muriate of baryta I again employ for manufacturing
white of baryta or blanc-fixe. The precipitated hydrate of magnesia
obtained by my method, as described, I either calcine and employ in
the preparation of magnesia cement, or I add the same to the pulp used
in making paper or papier mâché, or I use it for medicinal or other
chemical purposes.
In order to obtain pearl-hardening such as is required for the manu-
facture of paper or papier mâché, I mix a solution of Epsom salt or of
raw sulphate of magnesia, commonly called kieserit, in suitable pro-
- portions with pure caustic lime or with lime white, and the compound of
sulphate of lime and hydrate of magnesia resulting from this process
as a precipitate I submit to an ablution, whereby it is rendered suitable
for use as pearl-hardening in the manufacture of paper or papier mâché.

page_text: Instead of caustic lime I prefer in some cases to use or employ caustic
baryta or caustic strontia, and thus I realize mixed precipitates of
sulphate of baryta or of sulphate of strontia with magnesia.
'
By a modification of my process, I prepare a solution of muriate of
lime by adding hydrate of lime to a solution of muriate of magnesia, or
by dissolving limestone in muriatic acid, and this solution I mix with
a solution of sulphate of magnesia so as to obtain sulphate of lime as -
a precipitate, which, after a thorough previous ablution, may be used
as pearl-hardening, either by itself, or mixed with precipitated hydrate
of magnesia. The product thus obtained I not only use as pearl-
hardening for the manufacture of paper or papier mâché, and for mixing
colors for paper hangings, but also for any of the other purposes for
which precipitated or fine-ground sulphate of lime is usually employed.
For dressing or finishing spun or woven fabrics, I prefer either to pass
these through a solution of sulphate of magnesia, commonly called
kieserit, or Epsom salt, or else I apply to the fabrics thus steeped a
solution of muriate of lime, muriate of baryta, or muriate of strontia, or
lime white, hydrate of baryta, or hydrate of strontia, whereby additional
gloss and weight is given to these fabrics.
Having now described the nature of the said Invention, I wish it to
be understood that what I claim is :-.
:
First. The use of a solution of sulphate of magnesia added to soluble
salts of baryta, in the manner described, for preparing cements or
artificial marble, for dressing spun fabrics, or for precipitating muriate
of lime, to be used in making white of baryta or blanc-fixe, or for
precipitating hydrate of magnesia, to be either calcined and made into
magnesia cement, or to be added to paper pulp, or to be used for
medicinal or other chemical purposes.
Second. The use of a precipitate of kieserit or Epsom salt, mixed
with caustic lime, caustic baryta, or caustic strontia, in the manner
described, as pearl-hardening for paper or papier mâché making.
.
Third. The precipitating of sulphate of lime by mixing a solution of
muriate of lime, obtained in the manner described, with a solution of
sulphate of magnesia, and the use of this product, after ablution, either
by itself, or mixed with precipitated hydrate of magnesia, as pearl-
hardening for paper or papier mâché making, or for other kindred
purposes.

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Fourth. The dressing or finishing of spun or woven fabrics by
steeping the same in a solution of sulphate of magnesia derived from
kieserit or Epsom salt, or by applying to them thus steeped a solution
of muriate of lime, muriate of baryta, or muriate of strontia, or lime
white, hydrate of baryta, or hydrate of strontia, in the manner t
described.
In witness whereof, I, the said Joseph Theodore Dann, have here-
unto set my hand and seal, this Twenty-fifth day of August, in the
year of our Lord One thousand eight hundred and seventy-one.,