IMPROVEMENTS IN PRESERVING BLOOD FOR USE AS FOOD
Year: 1868

page_text: LETTERS PATENT to James Dewar, Doctor of Medicine, residing in
Kirkcaldy, in the County of Fife, North Britain, for the Invention
of "IMPROVEMENTS IN PRESERVING BLOOD FOR USE AS FOOD."
Sealed the 28th April 1868, and dated the 3rd March 1868.
PROVISIONAL SPECIFICATION left by the said James Dewar at
the Office of the Commissioners of Patents, with his Petition, on
the 3rd March 1868.
I, JAMES DEWAR, Doctor of Medicine, residing in Kirkcaldy, in the
County of Fife, North Britain, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN PRESERVING BLOOD FOR USE AS FOOD," to
be as follows:--
Blood is a nutritious article of food both for man and for the lower
animals, but it quickly and readily becomes decomposed, in which con-
dition it is unsuitable for food.
My Invention consists in so treating and preserving blood as that
it shall remain for a lengthened period wholesome and suitable for
use as food for man and for horses, cattle, sheep, poultry, and other

page_text: lower animals. To effect this object I either subject the blood of newly
slaughtered animals to careful desiccation by exposure to a temperature
between sixty and one hundred and forty degrees of Fahrenheit so as
to expel the moisture while preserving and concentrating the nutritious
qualities of the blood. Or I mix such blood with meal, flour, seeds,
husks of seeds, grain, or other farinaceous matter or roots either in
their natural state or dried and chopped up, ground down or pulverized
(for the food of animals other than man I sometimes add powdered
oil cake to the mass). I next subject the mixture to careful desic-
cation as before described. Blood when treated as above specified will,
if carefully kept dry remain in a condition suitable for the food of
man and of horses, cattle, sheep, poultry, and other lower animals for
a length of time, but I use in preference when I wish to preserve
the blood for a considerable period, the following methods, viz.,-I either
mix the fresh blood with an aqueous solution of sulphurous acid, or
with sulphurous acid in combination with an alkali in the form of a
sulphite and then mix the blood so treated with any of the solid sub-
stances before mentioned and submit the mixture to desiccation as
before described; or I mix the fresh blood with the said aqueous solution
of sulphurous acid alone, or with sulphurous acid in combination with
an alkali in the form of a sulphite without mixing it with any solid
substance, and then keep the blood so treated either in a liquid state
until required for use, or I desiccate it as before described and
keep it dry.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Dewar in the Great Seal Patent Office on
the 20th August 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
DEWAR, Doctor of Medicine, residing in Kirkcaldy, in the County of
Fife, North Britain, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of March, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said James Dewar, Her special licence that I,

page_text: the said James Dewar, my executors, administrators, and assigns, or
such others as I, the said James Dewar, my executors, administrators,
and assigns, should at any time agree with, and no others, from time
to time, and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN PRESERVING BLOOD
FOR USE AS FOOD," upon the condition (amongst others) that I, the said
James Dewar, my executors or administrators, by an instrument in
writing, under my, or their, or one of their hands and seals, should par-
ticularly describe and ascertain the nature of the said Invention and
in what manner the same was to be performed, and 'cause the same to
be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said James Dewar, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement :-
Blood is a nutritious article of food, both for man and for the lower
animals, but it quickly and readily becomes decomposed, in which
condition it is unsuitable for food.
The nature of my Invention consists in treating and preserving blood
as herein-after described, so that it shall remain for a lengthened period
wholesome and suitable for food, for man and for horses, cattle and
sheep, poultry, and other lower animals.
The manner in which my Invention is to be performed is as follows:-
When I wish to secure preservation for a short period of time only, I
either subject the blood of newly slaughtered animals to careful
desiccation by evaporation at a temperature between eighty and one
hundred and forty degrees of Fahrenheit, (I prefer a temperature of about
one hundred and thirty-five degrees) so as to expel the moisture, while
preserving and concentrating the nutritious qualities of the blood; or I
first mix such blood with meal, flour, seeds, husks of seeds, grain, or
other farinaceous matter or roots, either in their natural state or dried
and chopped up, ground down or pulverized (for the food of cattle and
such like herbivorous animals, I sometimes add powdered oil cake to
the mass), and I then subject the mixture to careful desiccation as
before directed. Blood when treated as above described will if carefully

page_text: kept dry remain in a condition suitable for the food of man, and of
horses, cattle, sheep, dogs, poultry, and the other lower animals for a
certain length of time, and from experience I find that it can be so
preserved for six weeks, but I use in préference, when I wish to preserve
the blood for a considerable period, the following methods, viz., I
either mix the fresh blood with an aqueous solution of sulphurous acid
or with sulphurous acid in combination with an alkali in the form of a
sulphite or bi-sulphite, and then mix such blood so treated with any of
the vegetable substances before mentioned and submit the mixture to
desiccation as before described; or I mix the fresh blood with the said
aqueous solution of sulphurous acid or with sulphurous acid in com-
bination with an alkali in the form of a sulphite or bi-sulphite without
mixing it with any other substance, and then either keep the blood so
treated in a liquid state until required for use, or I desiccate it as before
described and keep it dry.
In regard to the quantities of sulphurous acid and sulphites or
bi-sulphites which I employ, I find that one ounce of the aqueous
solution of sulphurous acid of the ordinary commercial strength, say
of specific gravity 1.012, is sufficient for twelve ounces of fresh blood,
and that one ounce of the sulphite or bi-sulphite suffices for the same
quantity, that is for twelve ounces of fresh blood. I find that horses
and oxen most readily eat the preserved blood when boiled along with
turnips and hay seed, which is a convenient form in which to give it
them. For the use of man, the preserved blood can conveniently be
made into biscuits, by mixing it with wheaten or other flour, or into
cakes by mixing it with oatmeal or other meal. It can conveniently be
used in the form of soup, by mixing it with water and cooking it with
vegetables, and otherwise in the manner usual in preparing soup.
In witness whereof, I, the said James Dewar, have hereunto set
my hand and seal, this Eighteenth day of August, in the year
of our Lord One thousand eight hundred and sixty-eight.