A NEW CHEMICAL PRODUCT FOR BLEACHING OR DECOLORIZING
Year: 1882

page_text: LETTERS PATENT to John Clayton Mewburn of 169 Fleet Street in the
City of London Patent Agent and Consulting Engineer for an Invention of
"A NEW CHEMICAL PRODUCT FOR BLEACHING OR DECOLORIZING." A com-
munication to him from abroad by Julien Vercruy-se-Degraeve of Bruges
Belgium.
PROVISIONAL SPECIFICATION left by the said John Clayton Mewburn at
the Office of the Commissioners of Patents on the 5th August 1882.
JOHN CLAYTON MEWBURN of 169 Fleet Street in the City of London Patent
Agent and Consulting Engineer "A NEW CHEMICAL PRODUCT FOR BLEACHING
OR DECOLORIZING " [A communication to him from abroad by Julien Vercruysse-
Degraeve of Bruges Belgium.]
The important part which the decolorizing hypochlorites and particularly
hypochlorite of lime (chloride of lime of commerce) and hypochlorite of soda
(sometimes called Javelle liquor) play in the art of bleaching is well known.
The low price of chloride of lime, its great richness in decolorizing product and
its easy carriage have led to its being adopted for most bleaching purposes such as
cotton, paper pulp and vegetable materials generally. It has however various
drawbacks and is far from offering the same advantages as an alkaline hypochlorite;
in fact it leaves in the pores of the material treated a white material from its
insoluble calcareous matters which gives it a disagreeable odour of chlorine and
considerably affects the fibres Alkaline hypochlorites contain a soluble base,
potass or soda, which does not lead to these drawbacks and it has been proved by
repeated experiments that by their use not only are the fibres not affected but they
acquire a much superior degree of whiteness.
Hitherto the relatively high price of the alkaline bypochlorites, the large volume
of water which they contain and consequently their inferior richness in decolorizing
property have caused them to be given up in large bleaching establishments.
It has therefore been a desideratum to obtain an alkaline hypochlorite which in
a small bulk shall possess considerable decolorizing power, be easily and cheaply
[Price 4d 1

page_text: carried and which in short without having the objections of chloride of lime and
Javelle liquor offers much more considerable advantages-Hitherto this has been
considered impracticable as it has been said that chlorine can only produce chlorates
and chlorides with the alkalies in concentrated solution. It has been proposed to
pass a current of gaseous chlorine through a bicarbonate of soda slightly
moistened with water but this has never gone beyond the laboratory. All other
attempts in the same direction have had uncertain and incomplete results.
Now by means of the present Invention alkaline hypochlorites can be made on
an economical scale at from 50 to 60 chlorometric degrees and even a crystallized
product possessing 400 degrees of decolorization-But this last product on account
of its great deliquescence is probably not of commercial value. These alkaline
hypochlorites are free from iron and are inade without chloride of lime; their
alkalinity makes them unctuous and greasy to the touch; they thus combine two
valuable properties, saponification and decolorization.
My new product is composed of a mixture of equal parts of hypochlorites of soda,
potass and magnesia, put in a solution with one thousandth of potassic permanganate.
It marks from 50 to 60 chlorometric degrees and from 25° to 30° of the acidometer.
By diluting it with from 50 to 60 times its volume of water, Javelle liquor is
obtained with economy of about 50 per cent.
The proportions before stated can be varied as experience may dictate.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Clayton Mewburn in the Great Seal Patent Office on
the 3rd February 1883.
°
JOHN CLAYTON MEWBURN of 169 Fleet Street in the City of London Patent
Agent and Consulting Engineer "A NEW CHEMICAL PRODUCT FOR BLEACHING
OR DECOLORIZING (A communication to me from abroad by Julien Vercruysse-
Degraeve of Bruges Belgium)
""
The important part which the decolorizing hypochlorites and particularly
hypochlorite of lime (chloride of lime of commerce) and hypochlorite of soda
(sometimes called Javelle liquor) play in the art of bleaching is well known.
The low price of chloride of lime, its great richness in decolorizing product and
its easy carriage have led to its being adopted for most bleaching purposes such as
cotton, paper pulp, and vegetable materials generally. It has however various
drawbacks and is far from offering the same advantages as an alkaline hypochlorite ;
in fact it leaves in the pores of the material treated a white material from its
insoluble calcareous matters which gives it a disagreeable odour of chlorine and
considerably affects the fibres.
Alkaline hypochlorites contain a soluble base, potass or soda, which does not
lead to these drawbacks and it has been proved by repeated experiments that by
their use not only are the fibres not affected but they acquire a much superior
degree of whiteness.
Hitherto the relatively high price of the alkaline hypochlorites, the large volume
of water which they contain and consequently their inferior richness in decolorizing
property have caused them to be given up in large bleaching establishments.
It has therefore, been a desideratum to obtain an alkaline hypochlorite which in
a small bulk shall possess considerable decolorizing power, be easily and cheaply
carried, and which in short without having the objections of chloride of lime and
Javelle liquor offers much more considerable advantages. Hitherto this has been
considered impracticable as it has been said that chlorine can only produce chlorates
and chlorides with the alkalies in concentrated solution. It has been proposed to
pass a current of gaseous chlorine through a bicarbonate of soda slightly moistened
with water but this has never gone beyond the laboratory. All other attemps in
the same direction have had uncertain and incomplete results.
Now by means of the present invention alkaline hypochlorites can be made on
an economical scale at from 50 to 60 chlorometric degrees and even a crystallized
product possessing 500 to 600 degrees of decolorization. But this last product on
account of its great deliquescense is probably not of commercial value. These
alkaline hypochlorites are free from iron and are made without chloride of lime;
their alkalinity makes them unctuous and greasy to the touch; they thus combine
two valuable properties, saponification and decolorization.
My new product is composed of a mixture of equal parts of hypochlorites of
soda, potass and magnesin, put in a solution with one thousandth of potassic
permanganate. It marks from 50 to 60 chlorometric degrees and from 25° to 30°
acid weight. By diluting it with from 50 to 60 times its volume of water, Javelle
liquor is obtained with economy of about 50 per cent.
The proportions before stated can be varied as experience may dictate.

page_text: Having now described the nature of the said Invention and in what manner the
same is to be performed as communicated to me I declare that I claim :-
The new chemical product for bleaching or decolorizing herein before described.
In witness whereof I the said John Clayton Mewburn have hereunto set my
hand and seal this third day of February One thousand eight hundred and
eighty three.
J. C. MEWBURN (L.S.)