AN IMPROVED METHOD OR PROCESS OF MANUFACTURING OR PREPARING THE CHEMICAL SALTS CALLED ACETATES
Year: 1839

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
ADOLPHE ROEDERER, of Strasburg, but at present residing at Wellington Street,
in the City of London, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Ninth day of April, in the second year of Her reign, did, for Hei-
self, Her heirs and successors, give and grant unto me, the said Charles Adolphe
Roederer, Her especial licence, full power, sole privilege and authority, that I, the
said Charles Adolphe Roederer, my exors, adñors, and assigns, or such others
as I, the said Charles Adolphe Roederer, my exors, admors, or assigns, should
at any time agree with, and no others, from time to time and at all times during
the term of years therein expressed, should and lawfully might make, use,
exercise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, the Invention of "AN IMPROVED METHOD OR PROCESS OF MANUFACTURING
OR PREPARING THE CHEMICAL SALTS CALLED ACETATES," partly invented by myself
and partly communicated by a foreigner residing abroad; in which said
Letters Patent is contained a proviso, that I, the said Charles Adolphe
Roederer, shall cause a particular description of the nature of the said Inven-
tion, and in what manner the same is to be performed, to be inrolled in
Her said Majesty's High Court of Chancery within six calendar months next
and immediately after the date of the said in part recited Letters Patent,
as in and by the same, reference being thereunto had, will more fully and at
large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Charles Adolphe Roederer, do hereby declare that the nature of my Inven-
tion, and the manner in which the same is to be performed, are particularly
set forth and explained in the following description thereof:-
The various processes which have hitherto been employed for the formation of
the acetates, and in particular the acetate or sugar of lead, consisted in mixing
the base with liquid acetic acid either in a concentrated or weak state. But
this mode of operating is productive of many serious disadvantages, amongst
which may be mentioned the expence of fuel, of apparatus, of labour, and of
time, the loss of acid, and the difficulty of producing acetates capable of
perfect crystallization and of pure quality. Most of these disadvantages are
obviated, and the remainder considerably moderated by my improved process,
which consists in employing the acid in the state of vapour to act upon the
bases instead of using it in the liquid form. I provide a vessel of adequate
capacity for the quantity of acetate I wish to make at once, and constructed
of such material as will not be readily destroyed by, the acid. The top of this
vessel I close hermetically by a cover fastened down by any convenient means,
and in the lower part of the vessel I place either a minutely perforated false
bottom or a coiled tube of several convolutions minutely perforated to permit
vapour to pass through freely. To prevent the loss of acid, I also place at
different degrees of elevation several perforated diaphragms similar to the
false bottom just mentioned, on each of which I spread a layer of litharge (if
I am making the acetate or sugar of lead or a layer of other proper base
according to the acetate required), after which the cover of the vessel is to be
accurately closed. By means of an ordinary distillatory apparatus, I convert
liquid acetic acid (strong or weak, pure or impure,) into vapour, which vapour
I conduct by means of a pipe into the convoluted perforated pipe before
mentioned, or between the real bottom of the vessel and the perforated false
bottom; hence the vapour passing through the numerous perforations of the
false bottom and diaphragms diffuses itself throughout every part of the vessel,
its acid entering into combination with the base employed, and forming the
acetate, which falls to the bottom of the vessel, and in its descent meets with
the ascending streams of vapour, the acid of which renders it perfectly neuter.
Meanwhile the more aqueous parts of the vapour becoming liberated and
maintaining their temperature ascend, and in their passage through the
successive layers of the base are thereby deprived of their remaining acid.
The vapour thus reduced to simple steam is allowed to escape through one or
more pipes at the top of the vessel, and as this steam still maintains a boiling
temperature, I conduct it through a worm to evaporate the acetates or the

page_text: mother liquor by its heat. The distillation of the acid is continued until the
acetate in the vessel is arrived at the proper degree of concentration for
crystallization, which is easily ascertained by examining a small quantity drawn
off by a cock at the bottom of the vessel, by which cock the whole contents
are discharged, when the operation is completed.
As the operation draws to its close by nearly all the base having combined
with the acid, the vapour issues out of the vessel charged with a certain
portion of acid, and in order that no loss may be sustained by its escape into the
atmosphere, it is conducted into another vessel, prepared like the first mentioned,
but charged superabundantly with the base to take up every particle of the
acid issuing out of the first vessel, until the operation in that first vessel
is ended.
The great saving of fuel effected by my process is evident from these cir-
cumstances, that my operation finishes where the ordinary one begins, and
that the mother liquor is evaporated by the latent heat of the aqueous vapour
before it is discharged. The apparatus is extremely simple and cheap, being
also self-acting, much labour is avoided by it, and finally, as the temperature of
the solution or the acetate can never exceed that of the vapour, the crys-
talline product is of finer quality than ordinary.
In witness whereof, I, the said Charles Adolphe Roederer, have here-
unto set my hand and seal, this Twenty-seventh day of September, in
the year of our Lord One thousand eight hundred and thirty-nine.
CHARLES ADOLPHE (L.S.) ROEDERER.
Taken and acknowledged by Charles
Adolphe Roederer (party hereto) at
Paris, this 27th day of September
1839, before me,
THOMAS PICKFORD,
Her Britannic Majesty's Consul at Paris.
бего
me this first day
1859.
S. DUCKWORTH.
George Bain, of Parliament Street, Westminster, in the County of Middlesex,
Gentleman, maketh oath and saith that he is acquainted with the manner and
character of the handwriting of Thomas Pickford, Her Britannic Majesty's.
Consul at Paris, in the Kingdom of France. And this deponent further saith,

page_text: that the name or signature. "Thomas Pickford," with the addition of "Her
Britannic Majesty's Consul at Paris," set, subscribed, and written upon or
indorsed in the margin of the Specification marked A, hereunto annexed, and
dated the Twenty-seventh day of September now last past, and purporting to
be executed by Charles Adolphe Roederer, of Stratsburg, Gentleman, whereby
it is stated that the said Specification was acknowledged by the said Charles
Adolphe Roederer before the said Thomas Pickford on the said Twenty-seventh
day of September, is of the proper handwriting of the said Thomas Pickford;
and that the said Thomas Pickford, at the time of setting and subscribing
his name on the said Specification in manner above stated, was and now is
Her Britannic Majesty's Consul at Paris...