AN IMPROVED METHOD OF MANUFACTURING VERDIGRIS, OF THE SAME QUALITY AS THAT KNOWN IN .COMMERCE BY THE NAME OF FRENCH VERDIGRIS
Year: 1814

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
BENECKE, of Deptford, in the County of Kent, Gentleman, send greeting.
WHEREAS His most Excellent Majesty King George the Third did, by
His Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twelfth day of Novem-
ber, in the fifty-fifth year of His reign, give and grant unto me, the said
William Benecke, my exors, adñiors, and assigns, His especial licence, full
power, sole privilege and authority that he, the said William Benecke, my
exors, adiñors, and assigns, should and lawfully might, during the term of
years herein. mentioned, make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, my Invention of "AN IMPROVED
METHOD OF MANUFACTURING VERDIGRIS, OF THE SAME QUALITY AS THAT KNOWN IN
.COMMERCE BY THE NAME OF FRENCH VERDIGRIS;" in which said Letters Patent
there is contained a proviso that if I, the said William Benecke, 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 recited Letters Patent, that then the said Letters
Patent, and all liberties and advantages whatsoever thereby granted, shall
utterly cease, determine, and become void, as in and by the same (relation
being thereunto had) may more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
William Benecke, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are particularly
described and ascertained as follows, that is to say:-
(1st.) Verdigris can be produced only by acetic acid, or all substances that
contain it in a free or even incipient state.
(2ndly.) The strongest kinds of acid appear to me the best adapted for the
manufacture. In this I include all vinegars or liquors containing the acetic
acid made from sugar; malt, grain, wood, or other vegetables.
(3rdly.) Vinegar, or the fluids containing the acetic acid, can produce ver-
digris only when applied in the state of vapour to copper; but in this state
it will have the desired effect whether it be sponges, woollen, cotton, linen,
or hair cloth, in fact by all substances that can retain the acetic fluid.
(4thly.) The particular art in making verdigris is, to contrive that the vapor
may be disengaged from the substances containing the acetic acid; that a
sufficient and not too great access be given to the air; and that the vapors
may be allowed to attach themselves to the surface of the copper, which is
*done by moderating the pressure by interposing hard substances between the
stratified copper and the containing substance, without, allowing the vapors
which are essential in the formation of verdigris to escape: My procedure is
as follows, viz, I lay copper plates alternately with woollen, cotton, linen,
felt, or hair cloth, or any other substance capable of holding acid (giving,
however, the preference to a substantial well-shorn woollen cloth, which cloth
or stuff is wetted before with acetic acid, made in any way by fermentation, dis-
tillation, decomposition, &c. Every real acetic acid will answer the purpose; tho'
I give the preference to distilled and highly purified acid. Between each stratifi-
cation some small pieces of wood, or of other hard substance, are put to prevent
too much pressure, to give access to the air, and to bring the vapors of acetic
acid into contact with the copper; so that a combined operation of the acid
(which now attaches itself as it were in a distilled state to the copper) and of
the oxigene of the atmospheric air takes placé: In this state I let it remain
undisturbed for some time, until an: efferescence of verdigris. has taken place,
which efferescence appears and ripens sooner or later, according to the place
where the sheets are kept; and to the temperature and co-operation of the
atmosphere. The verdigris is then either scraped off or fed before this
operation by sprinkling the plates or dipping them in water or other fluids, as
wine, deluted acid, &c. The verdigris is then cleaned as accurately as possible
from all foreign substances, and prepared in the usual way for the market.
The verdigris thus obtained will be at great perfection. The cloth and the

page_text: In witness whereof, I, the said William Benecke, have hereunto set my
hand and seal, this Fifth day of May, in the year of our Lord One
thousand eight hundred and fifteen.
Inrolled the Fifth day of May, in the year of our Lord One thousand
eight hundred and fifteen.