A NEW MATERIAL TO BE USED IN THE MANUFACTURE OF ARTED GENETTAD ",MEL OTHER SIMILARPRODUCT
Year: 1855

page_text: LETTERS PATENT to Charles Emile Paris, of Paris. in the Empire of
France, and of 4, South Street, Finsbury, London, Chemist, for the
Invention of "A NEW MATERIAL TO BE USED IN THE MANUFACTURE OF
ARTED GENETTAD
"
PROVISIONAL SPECIFICATION left by the said Charles Emile Paris at
the Office of the Commissioners of Patents, with his Petition, on the
28th July 1855.
1, CHARLES EMILE PARIS, of Paris, in the Empire of France, and of 4, South
Street, Finsbury, London, Chemist, do hereby declare the nature of my said
Invention for "A NEW MATERIAL TO BE USED IN THE MANUFACTURE OF CRYSTAL,
ENAMEL, AND OTHER SIMILAR PRODUCTS." to be as follows, that is to say :-
The Invention consists in the employment of sulphate of lead, for super-
seding in whole or in part the use of minium, or red lead, entering into the
composition of every kind of silicates having lead as its base, such as crystal,
enamel, and other similar products.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Emile Paris in the Great Seal Patent Office on the
28th January 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
EMILE PARIS, of Paris, in the Empire of France, and of 4, South Street,
Finsbury, London, Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of July, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself. Iler heirs and successors, give and grant unto me,
the said Charles Emile Paris, Her special license that I, the said Charles
Emile Paris, my executors, administrators, and assigns, or such others as I, the
said Charles Emile Paris, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times there-
after 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 "A NEW MATERIAL TO
BE USED IN THE MANUFACTURE OF CRYSTAL, ENAMEL, AND OTHER SIMILAR PRODUCTS,"
upon the condition (amongst others) that I, the said Charles Emile Paris,
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
Scal Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
"
NOW KNOW YE, that I, the said Charles Emile Paris, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement thereof, that is to say
My improvements consist in employing sulphate of lead as a substitute for
minium in the manufacture of glass and other vitreous products.
Besides the frequent presence of copper and iron in minium and the high
price of this product, its manufacture offers many difficulties and dangers to the
health of the workmen. By my Invention these defects are obviated, by
employing sulphate of lead in place of minium. Even when the lead from
which the sulphate is obtained contains copper or iron, this salt would be free
from them; the sulphates of iron and copper being soluble, and easily removed'
by washing.
Sulphate of lead is from its nature infusible, and is for this reason unsuitable

page_text: for the formation of silicates.
I therefore propose to decompose the sulphuric
a part of its
acid, which renders it infusible, so as to render available the oxide of lead
which it contains. In forming the mixture of the material, as herein-after
described, my object is to decompose the sulphate of lead by charcoal, for
instance, which takes from the sulphuric acid of the sulphate
oxygen for the formation of carbonic acid and of sulphurous acid gas. The
oxide of lead being thus set free, at once combines with the sand, forming
silicate of lead, which may then be employed for the formation of crystal,
enamel, &c.
Glass can be obtained by substituting sulphate of lead for minium in the
compound of materials generally used to produce this article.
I obtain,
however, a more favorable result by operating according to the frit method.
Up till now, when sulphate of soda has been substituted for the carbonate in
the manufacture of glass, it became necessary to add to it a proportion of
charcoal sufficient to decompose the sulphuric acid employed. The direction
of this operation gave rise to difficulties, owing to the coloration produced by
having the sulphuret of sodium or the charcoal in excess.
By the improved process this operation is now easily performed. In using
sulphate of lead, the charcoal requisite for the decomposition of the acid should
not exert its influence on the oxide (preserved besides by its combination with
the silica), because the lead reduced would remain partly divided in the glass.
An excess of charcoal is therefore to be avoided; but, on the other hand, as
it is burnt during the reaction, it is requisite to introduce into the mixture a
rather greater proportion of charcoal than the equivalent of oxygen of the acid
of the sulphate. A slight excess of sulphate does not offer any serious incon-
venience. This sulphate decomposes with difficulty by heat, but separates
freely with the small quantity of sulphate of potass contained even in purified
potass, and forms a kind of glass galls, which are easily removed.
MODE OF OPERATING.
I mix together about one hundred parts of sand, ninety parts of sulphate of
lead, and six parts of charcoal, which I place in the oven to make the frit.
When the frit is satisfactorily obtained, it is lifted up and turned over by
means of a wooden shovel, and when found to be uniform throughout, it is
removed from the fire, then pulverized, and the necessary quantity of purified
potass being added, it is melted as usual.
The glass being refined to the degree known to glass manufacturers, is
submitted to the ordinary working process. Crystal and other like products
may be obtained by following the process herein laid down.

page_text: I would observe, in conclusion, that although I mentioned charcoal as one of
the means to be employed in the decomposition of the sulphuric acid of the
sulphate of lead, I would have it understood that it is nevertheless possible to
employ any other substance capable of disoxigenating the sulphuric acid, so as
to transform it into sulphurous acid gas.
Having now described the nature of my said Invention, and the manner in
which the same is to be performed, I would have it understood that I do not
confine myself to the precise proportions herein laid down; but what I claim
is, the employment of sulphate of lead as a substitute in whole or in part for
minium, entering into the composition of all silicates having lead as a base,
for the manufacture of glass and other vitreous products.
In witness whereof, I, the said Charles Emile Paris, have hereunto set
my hand and seal, this Twenty-fifth day of January, in the
our Lord One thousand eight hundred and fifty-six.
year of
C. E. PARIS. (L.S.)