IMPROVEMENTS IN GALVANIC BATTERIES, AND IN OBTAINING CHEMICAL PRODUCTS THEREFROM
Year: 1852

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MARTIN
JOHN ROBERTS, of Woodbank, Gerrard's Cross, in the County of Buckingham,
Esquire, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Tenth day of February,
(in the year of our Lord One thousand eight hundred and fifty-two,) in
the fifteenth year of Her reign, did give and grant unto me, the said Martyn
John Roberts, my exors, admors, and assigns, Her especial licence, full power,
sole privilege and authority, that I, the said Martyn John Roberts, my exors,
adiñors, and assigns, and such others as I, the said Martyn John Roberts,
my exors, admors, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term of years therein
mentioned, should and lawfully might make, use, exercise, and vend, within
that part of the United Kingdom of Great Britain and Ireland called England,
the Dominion of Wales, and the Town of Berwick-upon-Tweed, in the Islands
of Jersey, Guernsey, Alderney, Sark, and Man, and in all Her said Majesty's
Colonies and Plantations abroad, my Invention of "IMPROVEMENTS IN GALVANIC
BATTERIES, AND IN OBTAINING CHEMICAL PRODUCTS THEREFROM;" in which said
Letters Patent there is, amongst others, contained a proviso that if I, the said
Martyn John Roberts, shall not particularly describe and ascertain the nature
of my said Invention, and in what manner the same is to be performed, by

page_text: an instrument in writing under my hand and seal, and cause the same 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 recited Letters
Patent, that then the said Letters Patent, and all liberties and advantages
whatsoever thereby granted, shall utterly cease, deterinine, and become void,
as by the said Letters Patent, reference being thereunto had, will more fully
and at large appear.
NOW KNOW YE, that in compliance with the said recited proviso, I, the
said Martyn John Roberts, do hereby declare the nature of my Invention,
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement, that is to say :--
My improvements consist, firstly, in employing tin as a positive plate in a
galvanic battery in conjunction with platinum, or any other substance being a
conductor of electricity which is electro negative with respect to tin, or which
will form with it a galvanic pair, or series of galvanic pairs, when duly
excited.
The exciting fluid which I use consists of an acid which acts powerfully
upon tin. The most efficient acids, which at the same time can be used
economically, are, I believe, nitric acid and nitro-muriatic acid.
The acid employed for the purpose of exciting the plates may be used either
in a free state or combined with any base which the acid will quit to unite
with the tin, and by quitting such base and uniting with some of the tin com-
posing the tin plate, will produce the chemical operation upon the tin plate
necessary for obtaining the desired electrical action.
The combinations of an acid with bases which I deem to be the most
efficient for this purpose are the nitrates of the metals which are electro
negative with respect to tin, and I prefer the nitrate of copper. When these
combinations are used to excite the plates they must of course be in a state of
solution. The exciting fluid I prefer to use is nitric acid, which may be
diluted more or less according to the electric energy which the batteries may
be required to exercise. By adopting this course I not only produce the
electric action which I desire, but I also obtain chemical products of commer-
cial value. For example, if I excite the tin and platinum in the battery by
nitric acid I obtain an oxide of tin (sometimes called stannic or meta-stannic
acid,) which is deposited in the cell containing the exciting solution. This
oxide of tin I combine by an easy and well-known process with soda, thus
forming stannate of soda, an article of great demand for dyeing and printing
textile fabrics. If the exciting fluid employed be nitro-muriatic acid the pro-
duct will be chloride or bichloride of tin, a salt also used in the same arts.

page_text: And in every case I select such an exciting fluid as will not only produce an
electric action of the desired energy, but also yield me a product which for
the time being I may find to be of the greatest commercial value; and I
select such one or more of the chemical agents above mentioned to compose.
my exciting fluid as will enable me to produce the above results (as far as
may be practical) in the manner which will be known to every chemist.
When I use nitric acid of specific gravity of not less than about 1.200 as
the exciting solution I obtain, as I have said, an oxide of tin. This product
is insoluble and precipitates to the bottom of the cell, and for the purpose of
preventing any impediment to the action of the plates in such cases I make
the cells of the battery deeper than the plates which are immersed in the
exciting liquid, so as to leave spaces in the bottoms of the cells in which the
oxides may be deposited. This oxide of tin falls down in the state of a
hydrate, thus carrying with it a considerable quantity of water. The forma-
tion of this hydrate has the effect therefore of preventing the strength of the
exciting fluid from being diminished so much as it otherwise would be.
When the action of the exciting solution on the tin plates evolves a con-
siderable quantity of heat, the chemical action, and consequently the electric
current, will become thereby much more powerful, and when desirable I
regulate or controul the action (if excessive) by surrounding the cells of the
battery with cold water, or employ any other efficient refrigerator, according
to the effect intended to be produced. And in order that the cooling body or
mixture may produce its cooling effect in the most rapid and efficient manner
on the exciting solution, and on the metals within the cells, I form the cells
of metal, as being the best conductor of heat, and I coat it with an enamel,
glaze, or other covering which will not be acted upon by the acid or other
chemical agent within the cell, in order to prevent the destruction of, or any
injurious action upon, the body of the cell itself.
Another part of my Invention consists in the employment of copper as a
positive metal in conjunction with platinum or other metal which is electro
negative with respect to copper, employing in this case as the exciting fluid
nitric acid or nitro-muriatic acid, more or less diluted according to the amount
of the electric action which may be desired.
The salts of copper resulting
from the working of a battery of this description are products which are
valuable in the arts, as, for example, in calico printing, and for other purposes,
and some of them may be used to excite a tin or zinc plate in another
battery.
By the above arrangements of galvanic batteries I am enabled to generate
electricity for useful purposes at a very small cost.

page_text: Having now described the nature of my Invention, and the manner in
which the same is to be performed, I claim as my Invention,-
First, the use of tin as a positive metal in a galvanic battery, and acted
upon by an acid or acids in manner and for the purposes herein-before de-
scribed.
And, secondly, I claim the use of copper as a positive metal in a galvanic
battery acted upon by an acid or acids in manner and for the purposes herein-
before described.
In witness whereof, I, the said Martyn John Roberts, have hereunto set
hand and seal, this Tenth day of August, in the year of our Lord
One thousand eight hundred and fifty-two.