IMPROVE- MENTS IN THE METHOD OF DETERMINING ORGANIC MATTERS CONTAINED IN. SOLUTIONS
Year: 1878

page_text: LETTERS PATENT to James Alfred Wanklyn, Professor of Chemistry, and
William John Cooper, Analytical Chemist, both of Westminster Chambers,
Westminster, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN THE METHOD OF DETERMINING ORGANIC MATTERS CONTAINED IN.
SOLUTIONS"
!
Sealed the 15th October 1878, and dated the 15th April 1878.
PROVISIONAL SPECIFICATION left by the said James Alfred Wanklyn and
William John Cooper at the Office of the Commissioners of Patents on the.
15th April-1878.
JAMES ALFRED WANKLYN, Professor of Chemistry, and WILLIAM JOHN COOPER,
Analytical Chemist, both of Westminster Chambers, Westminster, in the County of
Middlesex. "IMPROVEMENTS IN THE METHOD OF DETERMINING ORGANIC MATTERS
CONTAINED IN SOLUTIONS."
This Invention relates to an improved method of determining organic matters
contained in solution, and consists in effecting the measurement or determination of
the organic matters in solution.
In carrying out our Invention we proceeed as follows:-We employ a “standard”
solution of permanganate of potash as the oxydising agent, and we measure the
quantity of permanganate employed in the usual manner, but instead of simply
adding the permanganate to the acidified solution we render the solution alkaline
and then boil it with a known volume of the permanganate, and thereby oxidize
the organic matters at a boiling heat. We then allow the liquid to cool, acidify the
saine, and then ascertain by any of the ordinary processes how much permanganate
remains unconsumed.
The difference between the quantity of the permanganate added originally to the
solution before boiling, and that found afterwards, is the actual amount of perman-
ganate consumed by the organic matters in solution.
:

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Alfred Wanklyn and William John Cooper in the Great Seal
Patent Office on the 15th October 1878.
JAMES ALFRED WANKLYN; Professor of Chemistry, and WILLIAM JOHN COOPER,
Analytical Chemist, both of Westminster Chambers, Westminster, in the County of
Middlesex. " IMPROVEMENTS IN THE METHOD OF DETERMINING ORGANIC MATTERS
CONTAINED IN SOLUTIONS."
Our said Invention relates to an improved method of determining organic mat-
ters contained in solution, and consists in effecting the measurement or determina-
tion of the organic matters in solution.
In carrying out our said Invention we proceed as follows:-We employ a
"standard" solution of permanganate of potash as the oxydizing agent, and we
measure the quantity of permanganate employed in the usual manner, but in lieu
of simply adding the permanganate to the acidified solution we render the solution
alkaline, and then boil it with a known volume of the permanganate, and thereby
oxydize the organic matters at a boiling heat. We then allow the liquid to cool,
acidify the same, and then ascertain by any of the ordinary processes how much
permanganate remains unconsumed.
The difference between the quantity of the permanganate added originally to the
solution before boiling, and that found afterwards, is the actual amount of perman-
ganate consumed by the organic matters in solution. We find it convenient to make
the "standard" solution of permanganate of potash by dissolving sixteen parts, by
weight, of permanganate of potash in ten ten thousand parts, by weight, of water,
and to make the solution of alkali by dissolving five parts, by weight, of potash
in one hundred parts, by weight, of water.
We find it convenient to employ a weak solution of protosulphate of iron, rendered
strongly acid, with sulphuric acid for ascertaining the strength of the liquid to which
the permanganate has been added.
Our process is particularly useful for determining the amount of organic matter
present in different drinking waters; and in applying it for this purpose we
operate in the following manner-One pound of water is placed in a clean glass
retort; into the retort five ten-grain measures of the above-described solution of
caustic potash is placed, and then five ten-grain measures of the above-described
solution of permanganate are added. The contents of the retort are made to boil
by being heated in any convenient manner. If the colour of the permanganate
disappears a further addition of five ten-grain measures of the standard solution is
made, and this is repeated until the color of the permanganate ceases to be sensibly
weakened on boiling. That point having been reached, dilute sulphuric acid is
added, until the contents of the retort exhibit a strongly acid reaction. The standard
solution of iron is then dropped in, and the point is noted at which the color of the
permanganate disappears.
From this operation we arrive at this result, that a certain known quantity of the
above-described permanganate solution has been boiled with the water, and that
after the boiling a certain known quantity of the permanganate solution (represented
by the iron solution employed) remains unchanged after the action of the organic
matter. The difference between these two amounts is the amount of permanganate
solution consumed by the organic matter in the water. With impure drinking
water, especially peaty water, the quantity of permanganate consumed is very large;
but with pure water, and especially with deep spring water, the quantity consumed
is very small.
The process above described is specially applicable to measure the degree of
defilement of samples of water, whether that defilement be due to leakage of sewage
into the water or to the contact of the water with foul air. And by bringing foul
air into contact with water and our solution we are able to measure the degree of
defilement of the air by working our process as above described.

page_text: Having now described and particularly ascertained the nature of our said Inven-
tion, and the manner in which the same is or may be used or carried into effect, we
will observe in conclusion that what we consider to be novel and original, and
therefore claim as the Invention secured to us by the herein-before in part recited
Letters Patent is, determining or measuring organic matters contained in solutions
substantially in the manner herein-before described.
In witness whereof, we, the said James Alfred Wanklyn and William John
Cooper, have to this our Specification set our hands and seals, the Twelfth
day of October, One thousand eight hundred and seventy-eight.
JAMES ALFRED WANKLYN. (LS.)
WILLIAM JOHN COOPER.
(L.S.)