IMPROVEMENTS IN RENDERING CANVAS AND OTHER FABRICS AND LEATHER WATERPROOF
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
CONSTANTINE JENNINGS, of Great Tower Street, in the City of London,
Practical Chemist, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain and Ireland, bearing
date at Westminster, the Twenty-third day of July (One thousand eight hundred
and fifty), in the fourteenth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Henry Constantine Jennings, my
exors, admors, and assigns, Her especial licence, full power, sole privilege
and authority, that I, the said Henry Constantine Jennings, my exors, admors,
and assigns, or such others as I, the said Henry Constantine Jennings, my exors,
admors, or assigns, should at any time agree with, and no others, from time
to time and at all times during the terms of years therein expressed, should
and lawfully might make, use, exercise, and vend, within England, Wales,
and the Town of Berwick-upon-Tweed, my Invention of "IMPROVEMENTS IN
RENDERING CANVAS AND OTHER FABRICS AND LEATHER WATERPROOF;" in which
said Letters Patent is contained a proviso that I, the said Henry Constantine
Jennings, shall cause a particular description of the nature of my said
Invention, and in what manner the same is to be performed, by an instru-
ment in writing under my band and seal, 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 Henry Constantine Jennings, 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 in and by the following statement
thereof, that is to say :-
My Invention depends on the decomposition of mineral or metallic salts by
soap by double decomposition all kinds of soluble metallic salts, and all kinds
of soluble soaps will produce the results I desire to obtain, videlicet, a very
insoluble body or varnish. For example, I take one hundred and twelve
pounds of soft soap, well known in commerce; I dissolve this by heating
it in a copper with twenty-five to thirty gallons of water; when perfectly
dissolved and mixed, and at the boiling point, say two hundred and twelve
degrees of Fahrenheit, I add slowly or by degrees fifty-six to sixty-six pounds of
sulphate of zinc, a chrystallized white salt, well known in commerce under the
name of white vitriol. The solution of soap and the soap itself is decomposed,
and the whole of the metallic soap rises to the top, leaving its water, &c. at the
bottom of the copper. The alkali of the soap combines with the sulphuric acid
of the salt and the oxide of the salt (oxide of zinc) combines with the oil or
stearine of the soap, and is perfectly insoluble. This, when cold, becomes a
hard white mass, and is taken off the liquor (or solution or sulphate of
potassa or soda, as may be, when a hard soap is used). This is reboiled
in fresh water at the boiling heat, which heat will melt the metallic soap; and
it is necessary to remove any sulphate of soda or potassa that may be acci-
dently mixed or hang about the metallic soap, so as to render it pure, and
free from all soluble matter. I now take fifty gallons of raw linseed oil,
which should be as free from mucilage as possible, put this into a copper
with five pounds of American pearlash, or with carbonate of potassa, and one
gallon of water, boil these until the mass becomes white and opaque, and
appear to be perfectly combined into a liquid soapy mass. When the oil is
required to be white and colorless, 1 now add ten pounds per centum (of the
weight of the oil) of animal charcoal, and an equal quantity of water, boil
these together at two hundred and twelve degrees of Fahrenheit for one hour,
then separate and filter to remove some phosphoric acid and phosphate of
lime that is mechanically mixed with the oil and renders it opaque; after this
the oil is colorless and transparent, but this point of the process is only
necessary when a very light dressing is required; then add two pounds and a
balf of acetate of lead, called sugar of lead, and two pounds of litharge and
four pounds of red lead and twenty-one pounds of black rosin, boil the whole
together for, about one hour at a temperature not exceeding two hundred and

page_text: twelve degrees Fahrenheit, taking care to stir the whole from time to time to
mix the ingredients and prevent their falling to the bottom of the copper by
their superior weight. Now add thirty pounds of the metallic soap, and keep
mixing the whole until all the metallic soap is dissolved and amalgamated
with the oil, &c., taking care never to elevate the temperature beyond two
hundred and twelve degrees Fahrenheit. When the mixture is complete I
add two gallons of solution of caoutchouc, made by dissolving twenty-four
ounces of caoutchouc in one gallon of essence of turpentine; I stir this in
thoroughly to be certain of its perfect mixture and amalgamation; when this
dressing is about one hundred and fifty to one hundred and sixty degrees, it
must be employed by brushes to the canvas on one side first, which must
then be suspended to dry, which takes place in about from twenty-four to
thirty-six hours in ordinary weather; after this a second coat is applied, always
at the same temperature, and these two coats when dry will be found in
general to fill the fibre of the canvas and prevent the action or penetration
of water. A third coat may be applied after the second is perfectly dry, and
this last will have a perfect face or varnish, if desirable. For leather I
employ the following process or preparation :-I dissolve equal parts of
metallic soap in raw linseed oil at the temperature of two hundred and twenty-
five degrees of Fahrenheit, and I put the leather, whether sole leather or
thinner leather, into this solution, and keep it until all the water and air con-
tained in the leather is expelled, and leave the leather in the solution until it
is cold; the difference of temperature acts on the interstices from whence the
air and water has been expelled by the temperature as a vacuum, and as the
temperature falls the liquid enters into the pores of the leather and becomes a
part of it, and renders it perfectly waterproof or hydruretted without rendering
it hard or brittle. I now scrape and wipe off the excess of liquid and let the
leather dry by the atmospheric action; this process will not take more than
forty-eight hours, including the saturation, which takes about three hours. All
the soluble metallic salts have the property of decomposing solutions of soft or
hard soap, and each metal gives its own peculiar color to the soap; for
example, sulphate of copper will produce a splendid green soap, sulphate of
iron a dark brown or chocolate color, acetate of lead and zinc a fine white,
the salts of cobalt a blue, &c., &c., &c. The advantage of this process is that
any act of piracy will be detected immediately, since the metallic base is
readily produced in all cases, and, therefore, cannot be accomplished without
chemical detection.
I claim the use of metallic soaps, as above produced, or by any other
means of double decomposition or chemical agency combined with raw

page_text: linseed oil, or linseed oil prepared as I have above indicated, and its applica-
tion to textile fabrics of every kind, and also for rendering leather waterproof.
I claim also the use of animal charcoal, as described by the above process, for
decolorating drying oils by first combining the oil with ammonia or either of
the fixed alkalies. I also claim the mode of using raw oils mixed with
any of the alkalies, and afterwards neutralized by acetate of lead or any
other chemical agent of analogous affinity. I also claim the use of boiled
oils or varnishes in combination with metallic soaps, as above described, when
the smell, colour, or application of the same will permit thereof, as dressings
for canvas, &c.
In witness whereof, I, the said Henry Constantine Jennings, have here-
unto set my hand and seal, this Twenty-first day of January, in the
year of our Lord One thousand eight hundred and fifty-one.