The Manufacture of Bromine Preparations for Sanitary and other Purposes.
Year: 1886

page_text: Date of Application, 7th May, 1886.
Complete Left, 7th Feb., 1887.
Complete Accepted, 8th Mar., 1887.
The Manufacture of Bromine Preparations for Sanitary and
other Purposes.
WILLIAM DALRYMPLE BORLAND, Consulting and Analytical Chemist, 35 Petherton
Road Highbury New Park London do hereby declare the nature of this invention
to be as follows-
The employment of Bromine for sanitary purposes has hitherto been very limited
owing to the danger and inconvenience attendant upon its application. This invention
provides means whereby bromine is brought into such a condition that in its application
it is safe and completely under the control of the user.
In carrying this invention into effect I may adopt two plans to regulate the action
of bromine. According to the one plan, I first prepare a mixture of a soluble bromide
with a soluble bromate, in the proportion of five molecules of the bromide to one
molecule of the bromate. I do not bind myself to employ the bromide and bromate
of any metal in particular, but I find that the bromide and bromate of sodium and of
potassium are very convenient, since it is possible to prepare a mixture of bromide and
bromate in the above molecular proportions by simply causing bromine to combine
with caustic or carbonated alkali best in solution, and then drying the mixed salts at a
temperature below that at which decomposition of the bromate takes place.
Having prepared the dry mixture of bromide and bromate in the above molecular
proportions, I next proceed to mix this intimately with an alkaline bisulphate, such for
example as sodium hydrogen sulphate, in the proportion of five molecules of the
bromide, one of the bromate, and six of the alkaline bisulphate, all being in the dry
and preferably finely granular condition.
This preparation only evolves bromine when moistened or heated, and is either
employed by itself or is combined by admixture with other substances valuable for
sanitary purposes, such for example as cupric sulphate, potassium chromate. potassium
permanganate, alum. boric acid, borax, in the dry condition.

page_text: I may also add a very small amount of a terpene or essential oil, since I have found
that such addition increases the keeping properties of the preparation and also imparts
to the bromine evolved a distinctly aromatic odour.
I may also mould the above bromine preparations by compression or otherwise into
cakes or pellets of various forms and sizes.
A cake or pellet may thus be made to contain a known amount of bromine, so that
the amount of bromine applied for any given purpose is regulated at will with the
maximum of ease, simplicity and certainty.
According to the other plan which I may adopt as a means of regulating the action
of bromine, I take solid paraffin wax and digest this in bromine until the latter is
saturated with the paraffin. I find by experiment that the point of saturation is
reached when one hundred parts of the solution of paraffin wax in bromine contain
about eleven paris of paraffin. I am not aware that this property which bromine
possesses of dissolving paraffin wax has ever been observed before, but whether this be
the case or not, the presence of this small amount of paraffin in solution exerts a
remarkable influence upon the rate of evaporation of the bromine. I have found by
experiment that this addition of paraffin renders the evaporation of the bromine
gradual and uniform, a property which I regard as of great value for the continued
disinfection of urinals, cesspools, sewers and the like. I have also found that in order
to obtain a rapid evolution of bromine, it is simply necessary to add to the solution of
paraffin in bromine, some finely divided substance such as sand, the increased rate of
volatilization being governed by the proportion of finely divided matter added.

page_text: COMPLETE SPECIFICATION.
The Manufacture of Bromine Preparations for Sanitary and
other Purposes.
I, WILLIAM DALRYMPLE BORLAND, Analytical and Consulting Chemist of 35
Petherton Road, Highbury New Park, London in the County of Middlesex do
hereby declare the nature of my invention for THE MANUFACTURE OF BROMINE
PREPARATIONS FOR SANITARY AND OTHER PURPOSES, and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement:-
The object of this invention is to provide preparations of bromine capable of evolving
that substance in the free state under convenient conditions and at the same time
devoid of the many disadvantages in respect of transport and application attendant
upon the employment of free bromine. In carrying this invention into effect, I first
prepare a mixture of a soluble bromide with a soluble bromate in the proportion of
five molecules of the bromide to one molecule of the bromate. I do not limit myself
to the employment of the bromide and bromate of any particular metal or base, but I
find the mixture of bromide and bromate of sodium, likewise of potassium to be very
convenient for my purpose, and I usually prepare the mixture of bromide and bromate
in the above molecular proportions by simply causing bromine to combine with the
caustic or carbonated alkali, best in solution, and then drying the mixed salts at
temperatures below that at which decomposition of the bromate takes place.
Having prepared the dry mixture of bromide and bromate in the above molecular
proportions, I next proceed to mix this intimately with an alkaline bisulphate such for
example as sodium hydrogen sulphate in the proportion of five molecules of the
bromide, one of the bromate and six of the alkaline bisulphate, all being in the dry
and preferably granular condition. Where it is necessary to use a concentrated form
of the bromine preparation, I take care that the alkaline bisulphate is approximately
free from neutral sulphate or other diluent. Where however an economical and some-
what less concentrated form of the preparation is required, I may conveniently employ
that residue from nitric acid manufacture called nitre-cake in the place of pure or
approximately pure bisulphate, and mix the powdered and granular nitre-cake with the
powdered and granular bromide and bromate in such proportions that the relation of
true bisulphate in the nitre-cake to the bromide and bromate is that of six molecules
of the bisulphate to five of the bromide and one of the bromate. I find good working
proportions to be as under :-
-
(1) For a strong preparation capable of evolving 34 per cent of bromine, I take
720 parts by weight of sodium hydrogen sulphate-Na HSO-, and 666 parts of sodium
bromide and bromate 5 Na Br + Na Br O₂.
(2) For a less concentrated preparation capable of evolving 6 per cent of bromine,
I take 7200 parts by weight of nitre-cake (with 10 per cent of actual bisulphate) and

page_text: 666 parts by weight of the molecular mixture of bromide and bromate represented by
the formula 5 Na Br + Na Br O₂.
The preparations of bromiue which I am enabled to make by the aid of this invention
only give off their bromine when moistened or strongly heated, and are intended to be
used as convenient sources of bromine for sanitary and other purposes such for example
as the extraction of gold from its ores.
I sometimes find it convenient especially when the preparations are to be employed
for sanitary purposes to combine the same by admixture with other substances of
value for such purposes, such as cupric sulphate, alum, boracic acid, borax, in the dry
condition.
I also find it of distinct advantage to add to the above bromine-evolving preparations,
a very small amount of a terpene, essential oil, camphor, phenol or hydrocarbon
separately or together, since such addition increases the keeping properties of the
preparations and also imparts to the bromine which is evolved a distinctly aromatic
odour. A good working proportion which I adopt is 10 drops of a solution of 1 part
of camphor in 2 of turpentine to one pound by weight of the bromine preparation.
I may also mould by compression or otherwise any of the bromine preparations
herein described into pellets or cakes of various forms and known weights so that it
becomes possible to regulate the amount of bromine applied to any given purpose with
a maximum of ease and certainty.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I declare that what I claim is :
(1) The manufacture of improved bromine-evolving preparations for sanitary and
other purposes substantially as set forth.
(2) The improved bromine-evolving preparations substantially as described.