A METHOD TO PREVENT OR PROTECT AGAINST FRAUD- ULENT PRACTICES UPON BANKERS' CHECKS, BILLS OF EXCHANGE, AND VARIOUS SPECIES OF MERCANTILE, COMMERCIAL, AND OTHER CORRESPONDENCE
Year: 1822

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBSON, of Saint Dunstan's Ilill, Tower Street, in the City of London, Printer
and Stationer, send greeting.
WHEREAS His most Excellent Majesty King George the Fourth did, by
His Letters Patent, under the Great Seal of His United Kingdom, bearing
date at Westminster, the Tenth day of December, 1822, in the third year
of His reign, give and grant unto me, the said William Robson, my exors,
adiors, and assigns, His especial licence, full power, sole privilege and autho-
rity, that I, the said William Robson, my exors, adiñiors, and assigns, during
the term of years therein mentioned, should and lawfully might make, use,
exercise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, my Invention of "A METHOD TO PREVENT OR PROTECT AGAINST FRAUD-
ULENT PRACTICES UPON BANKERS' CHECKS, BILLS OF EXCHANGE, AND VARIOUS
SPECIES OF MERCANTILE, COMMERCIAL, AND OTHER CORRESPONDENCE;" in which
said Letters Patent there is contained a proviso, that if I, the said William
Robson, shall not particularly describe and ascertain the nature of my
said Invention, and in what manner the same is to be performed, by an
instrument in writing under my hand and seal, and cause the same to be
inrolled in His Majesty's High Court of Chancery within six calendar months
next and immediately after the date of the said Letters Patent, that then the

page_text: said Letters Patent, and all liberties and advantages whatsoever thereby granted,
shall utterly cease, determine, and become void, as in and by the same (rela-
tion being thereunto had) will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Robson, do hereby declare that the nature and properties of my
Invention, and also the manner of performing the same most advantageously,
are herein set forth and explained; but in order to point out the use and
advantage of the same, I shall here observe, that the great ease with which
writing executed with common writing ink can be removed, discharged, or
obliterated by the application of oxalic and other acids has placed a dangerous
power in the hands of evil-disposed persons, and the frauds practised upon the
public by altering bankers' checks, bills of exchange, and various species of
mercantile correspondence by these means plainly shew the absolute necessity
of adopting some proper and efficient method to prevent so serious an evil.
Now, my Invention of a method to prevent or protect against fraudulent
practices upon bankers' checks, bills of exchange, and various species of
mercantile correspondence, consists in the application of any suitable vegetable
colour or colours, upon one or both sides of the paper or other article to
be written upon with common writing ink, for the purposes aforesaid, such
vegetable colour or colours being applied either by ruling any appropriate
lines with a pen, or any other convenient instrument or ruling machine, a
specimen of which is shewn, marked No. 1; or by mixing any proper vegetable
colour or colours with any suitable vehicle that will give it sufficient vicidity to
be used in a similar way, and as a printing ink, in which case any device or
form may be printed upon the paper or other article, either from wooden
blocks, types, composition, engraved or other plates, as shewn by the specimens
marked 2 and 3; and when the paper or other article is so imprinted or
prepared with such device, devices, or lines, then the writing with common
ink may be done or executed upon or over it in the usual way, and should any
attempt be made to remove, discharge, or obliterate the whole or any part
thereof, by using any acid, acids, or other chemical means that will remove,
discharge, or obliterate common writing ink, such acid, acids, or other chemical
means or process, it is well known, will produce such a change in the vegetable
colour as to prove, by mere inspection, that a fraud has been attempted, which,
by this method, will be prevented, if not detected; and I hereby declare, that
although a number of colours made from vegetable substances may be used
that will answer the purpose very well, yet I prefer an extract of saffron in
water, made of sufficient strength to tinge paper or any other suitable article

page_text: upon which it is used strongly; and in order to increase the brightness or
intensity of the colour, I add a very small quantity of the extract of Brazil
wood in water, and a few drops of pure ox gall to half a pint of the extract,
to make the liquid flow free from the pen or other instrument, which produces
an orange tint more suitable by its brightness to be applied on the front side
of any bankers' checks, bills of exchange, or other mercantile correspondence,
the writing done with common ink appearing very plain upon such a tint, when
applied in any device or form upon the front of any check, bill, or other article
of correspondence; but I prefer using an extract of log-wood for the back of
such paper or other article, because the brightness and intensity of the colour
is not of so much consequence, but the detecting properties of this extract,
when acids or other chemical processes are applied, will be found more effec-
tive. The extract of log-wood is made and applied by me in the following
manner-I boil any convenient quantity of chips or raspings of log-wood in
water, and evaporate it to the consistence of olive oil, when, by the addition of
a few drops of ox gall to half a pint of the extract, it will flow freely from a
pen or other convenient instrument with which any suitable device or lines
may be ruled or drawn upon the back of any check, bill, or other written
article of correspondence; and should any acid, acids, or other chemical process
be applied to discharge or obliterate the common writing ink, then the purple
tinge of the log-wood would be changed to a dull orange colour, which would
immediately expose the attempt, and thereby prevent the fraud. Where it is
desirable to use or apply the vegetable colour in the same manner as printing
ink, I prepare the extract of log-wood, as above described, without the ox gall;
I then use one pound of pure white chalk, one pound of Castile soap, and one
pound of powdered turmeric, mixed together and ground upon a marble slab,
adding as much of the extract of log-wood (before described) as will give it a
proper consistence, to be used as a printing ink. The thickness or consistence
of this composition may be encreased or diminished by adding to or lessening
the quantity of the several ingredients. And I hereby further declare, that
although I prefer the use of saffron, Brazil wood, log-wood, and tumeric, as
above described, yet any of the vegetable colours commonly used as chemical
tests will produce the same advantageous effects. And also a variety of liquids
may be added to the vegetable matters by way of menstrua, to extract their
colours, as, for instance, alcohol, brandy, or any other suitable kind of spirits,
and likewise a number of ingredients may be added to or mixed with the
vegetable colours, to give them a proper consistence to work freely, either as
fluids to be used with a pen or other instrument, or in the same manner as

page_text: printing ink, for instance, ox gall, treacle, soap, chalk, or flake white, either
seperately or mixed in such proportions as the judgment will dictate, or any
particular case or purpose may require.
In witness whereof, I, the said William Robson, have hereunto set my
hand and seal, this Seventh day of June, in the year of our Lord One
thousand eight hundred and twenty-three.