A NEW OR IMPROVED COMPOSITION OF LEAD FOR PENCILS, PARTICULARLY APPLICABLE TO MARKING LINEN, WHICH COMPOSITION MAY ALSO BE OTHERWISE APPLIED FOR MARKING
Year: 1877

page_text: LETTERS PATENT to Adolf Schroll, of No 2, Scott's Yard, Bush Lane, Cannon
Street, in the City of London, Merchant, for the Invention of "A NEW OR
IMPROVED COMPOSITION OF LEAD FOR PENCILS, PARTICULARLY APPLICABLE
TO MARKING LINEN, WHICH COMPOSITION MAY ALSO BE OTHERWISE APPLIED
FOR MARKING A communication from abroad by Fieduch Fioescheis, of
Nuremberg, Bavaria, Pencil Manufacturer
"
'
PROVISIONAL SPECIFICATION left by the said Adolf Schroll at the Office
of the Commissioners of Patents on the 29th January 1877
ADOLF SCHROLL, of No 2, Scott's Yard, Bush Lane, Cannon Street, in the City
of London, Merchant "A NEW OR IMPROVED COMPOSITION OF LEAD FOR PENCILS,
PARTICULARLY APPLICABLE TO MARKING LINEN, WHICH COMPOSITION MAY ALSO BE
OTHERWISE APPLIED FOR MARKING" .A communication from abroad by Friedrich
Fioescheis, of Nuremberg, Bavaria, Pencil Manufacturer
The composition, the subject of this Invention, is intended to produce a mark
which will neither rub nor wash out It consists of a combination of, firstly,
clay earth suitable for the purpose, such as potter's clay well ground, secondly,
nitrate of silver or silver salt soluble in watei, thudly, black lead carefully freed
from impurity by washing, or other coloring material, which will cause no dissolu-
tion of the silver salt employed
These substances are treated in the following manner and in the following pro-
portions One part of nitrate of silver dissolved in as little water as possible, to
this I add 8 to 12 parts of clay earth and one part of black lead or other coloring
matter, after properly mixing it together sufficient water is added in order to
procure a substance that may be shaped, and then pencils are formed and pressed in
a manner similar to that which is customary in making lead pencils
This composition may be placed in wooden holders like ordinary lead pencils,
or into any suitable propelling or other pencil case of wood or of metal, or it may
be used in the form of a powder to be rubbed over stencil plates, or it may be
appled in any other manner which may be found suitable
In writing upon linen with a pencil of this Invention the fabric should first be
damped and immediately after the marking be died with a hot non or otherwise,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Adolf Schioll in the Great Seal Patent Office on the 24th July 1877
ADOLF SCHROLL, of No 2, Scott's Yard, Bush Lane, Cannon Street, in the City
of London, Merchant "A NEW OR IMPROVED COMPOSITION OF LEAD FOR PENCILS,
PARTICULARLY APPLICABLE TO MARKING LINEN, WHICH COMPOSITION MAY ALSO BE
OTHERWISE APPLIED FOR MARKING" A communication from abroad by Friedrich
Froescheis, of Nuremberg, Bavaria, Pencil Manufacture:
The composition, the subject of this Invention, is intended to produce a mark
which will neither rub noi wash out It consists of a combination of,-1°, clay
earth, such as potter's clay, specially prepared for the purpose, 2°, nitrate of silver
or silver salt soluble in water, 3°, black lead or other coloring material which will
not cause any dissolution of the nitrate of silver employed
These substances are ticated and combined in the following manner - One part
of the nitrate of silver is dissolved in water, and to this solution, which must be
just sufficient to moisten the whole mass so that it is fit for pressing, there are
added three and a half (31/3) parts of the clay earth and one-half part (1/2) of the
black lead or other dye stuff or coloring material, the two latter materials must first
be very carefully ground, washed, mixed, and then moistened with the solution of
nitrate of silver in small parcels, and in order to secure a very equal distribution
of the solution the mass thus moistened must be ground and pressed. The com-
position thus formed is then pressed into pencils or into any suitable shapes, as in
the ordinary manufacture of lead pencils
The finished pencils may either be enclosed in wood or be placed in wood or
metal cases or holders, or they may be left uncovered in the form of leads or in
cakes.
The nitrate of silver, which by reason of its easy reduction in contact with
organic substances causes the marking to be indelible, is present in the finished
pencils in such a manner that it cannot dissolve, the nature of the substances with
which it is in combination being such that they aro and remain without any
chemical effect upon the nitrate of silver.
In using pencils made according to this Invention the linen is first slightly
damped, it is then written upon as with an ordinary pencil, whereby a small
quantity of the nitrate of silver contained in the pencil is dissolved and is thus
applied duect to the threads or fibre of the fabric, whilst the black lead or other
dyeing or coloring material selected in its stead serves only to render the writing at
once visible to the water and to facilitate a correct inscription. The parts of the fabric
which have been written upon should then be ironed with a hot iron or otherwise
heated, whereby the nitrate of silver is for the greater part reduced and unites
After the termination of
itself chemically with the fibie or thi cad of the fabric
this operation the writing appears upon the fabric of a dark brown color, and is not
changed by being washed or boiled either at onco or at any future time with soap
or soda, by washing with soda the black lead or other colouring matter, which
adheres only mechanically, is completely removed and the nitrate of silver is
perfectly fixed on the fibre or thread of the textile or other fabric, the acids which
might be liberated are at the same time chemically united by the alkalı of the soda
or soap mixture, and thus the possibly destructive effect thereof upon the fabric is
obviated
1 would here observe that the improved marking composition I have above
described is very suitable for stencilling, and may be applied to the marking of any
kind of fabric or material in any manner which may be found most suitable
Having now described and ascertained the nature of the Invention communicated
to me as aforesaid, and in what manner the same is or may be performed, I would
have it understood that the proportions above given are only approximative, and
may be varied to suit the quality of the substances used and other circumstances,
and that I'claim as secured to me by the herein-before in part recited Letters

page_text: Patent, the use of a composition consisting of nitrate of silver in combination with
a suitable clay and with black lead or other coloring matter, substantially as and
for the purposes specified
In witness whereof, I, the said Adolf Schroll, have hereunto set my hand and
seal, this Fourteenth day of July, in the year of our Lord One thousand
eight hundred and seventy-seven
ADOLF SCHROLL. (LS.)