Improvements in the Manufacture of Sheep-dipping Powders.
Year: 1895

page_text: Date of Application, 19th June, 1895
Complete Specification Left, 2nd Oct., 1895-Accepted, 18th July, 1896
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Sheep-dipping Powders.
We, FRANCIS WILLIAM PASSMORE, Analytical and Consulting Chemist, of
63 Queen Victoria Street, London, E.C. and JEYES' SANITARY COMPOUNDS
COMPANY, LIMITED, of 64 Cannon Street, London, Manufacturing Chemists, do
hereby declare the nature of this invention to be as follows:-
Sulphur and arsenic in various forms are largely used in sheep washes for the
purpose of preventing the attacks of insects, flys, etc., and to kill and arrest the
development of eggs deposited in the skin and wool of the sheep.
Flowers of sulphur, white arsenic, sulphide of arsenic and the usual mixtures
employed all possess the great disadvantage that they are powders insoluble in
water, which renders it impossible to effect an even distribution of the ingredients
throughout the bath, and necessitates the contents of the dipping tank being
continually stirred in order to prevent the powder settling.
Moreover the
antiseptics being deposited in the fleece in lumps are apt to cause sores.
The boiling of arsenic with alkalies to render it soluble, or the use of ready-made
soluble prepartions which are usually strongly alkaline, is on the other hand
strongly condemned because the strong alkali dissolves the yolk from the fleece,
and damages the fibre of the wool and renders it harsh, whilst the antiseptic being
in a soluble state is easily washed out again by rain, losing its permanent effect,
and also becoming a source of danger from poisoning the grass.
By our invention we have provided a means of adding sulphur or sulphur and
arsenic to the dipping-bath in the form of a soluble powder, so that a perfectly
uniform and even distribution of the antiseptic in the wash is first obtained, from
which the sulphur or sulphur and arsenic precipitate in the course of a few
minutes or hours, according to temperature and concentration of the solution, but
in such a finely divided state that the particles remain suspended in the solution
for a number of hours without stirring, forming a whitish or yellowish milky
emulsion. In this manner the thorough impregnation of the fleece with sulphur or
arsenic is ensured as well as their even distribution throughout the wool & skin in
an impalpably fine state of division, so that the particles adhere to the wool and
are not washed out by rain. Moreover the antiseptics deposited in the wool in a
nascent state are much more active and efficient and a very much smaller amount
of arsenic or of sulphur is therefore required.
These results are arrived at by employing mixtures of soluble sulphuretted
sulphates with solid acid substances that in the presence of water cause the
decomposition of the above sulphur compounds and deposition of sulphur. If
soluble arsenical compounds are present arsenic is also precipitated together with
sulphur as sulphide of arsenic.
In order to prepare a soluble sulphur powder we take, for example, thiosulphate
of sodium and mix it together with an excess of oxalic acid, taking care that no
water or moisture enters the mixture. To make an arsenical powder we further
add arsenic acid or a soluble salt of arsenic to the foregoing mixture, varying the
proportions of the ingredients accordingly as more or less sulphur or sulphide of
arsenic is desired in the insoluble precipitate that results from the addition of water
to the powder.
The sulphur or arsenical dipping powder is dissolved in water, when the wash

page_text: is ready for immediate use and remains efficient for a considerable length of
time.
These sulphur or arsenical sheep dips are suitable for employment with
coal-tar sheep dips.
Dated this 19th d 2005
improvements in the Manufacture of Sheep-dipping Powders.
We, FRANCIS WILLIAM PASSMORE, Analytical and Consulting Chemist, of
63 Queen Victoria Street, London, E.C. and JEYES' SANITARY COMPOUNDS
COMPANY LIMITED of 64 Cannon Street, London, Manufacturing Chemists, do
hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
Sulphur and arsenic in various forms are largely used in sheep washes for the
purpose of preventing the attacks of insects, flys, etc., and to kill and arrest the
development of eggs deposited in the skin and wool of the sheep.
Flowers of sulphur, white arsenic, sulphide of arsenic and the usual mixtures
employed all possess the great disadvantage that they are powders insoluble in water,
which renders it impossible to effect an even distribution of the ingredients through-
out the bath, and necessitates the contents of the dipping tank being continually
stirred in order to prevent the powder settling. Moreover the antiseptics being
deposited in the fleece in lumps are apt to cause sores.
The boiling of arsenic with alkalies to render it soluble or the use of readymade
soluble preparations which are usually strongly alkaline, is on the other hand strongly
condemned because the strong alkali dissolves the yolk from the fleece and damages
the fibre of the wool and renders it harsh, whilst the antiseptic dressing being in a
soluble state is easily washed out again by rain, losing its permanent effect, and
also becoming a source of danger from poisoning the grass.
By our invention we have provided a means of adding sulphur or sulphur and
arsenic to the dipping-bath in the form of a soluble powder, so that a perfectly
uniform and even distribution of the antiseptic in the wash is first obtained, from
which the sulphur or sulphur and arsenic precipitate in the course of a few minutes
or hours, according to temperature and concentration of the solution, but in such a
finely divided state that the particles remain suspended in the solution for a
number of hours without stirring, forming a whitish or yellowish milky emulsion.
In this manner the thorough impregnation of the fleece with sulphur or arsenic is
ensured, as well as their even distribution throughout the wool and skin in an
impalpably fine state of division, so that the particles adhere to the wool and are
not washed out by rain. Moreover the antiseptics deposited in the wool in the
nascent state are much more active and efficient and a very much smaller amount
of arsenic or of sulphur is therefore required.
These results are obtained by employing mixtures of soluble sulphuretted
sulphates with solid acid substances that in the presence of water cause the
decomposition of the above sulphur compounds and deposition of sulphur. If
soluble arsenical compounds are present arsenic is also precipitated together with
sulphur as sulphide of arsenic. It is essential that no water should enter into the
composition of these mixtures even as water of crystallisation, otherwise reaction
takes place between the ingredients in the solid state, with liberation of sulphur, or
sulphur and arsenic, in an insoluble condition.
In order to prepare a soluble sulphur powder we take for example 158 parts of
thiosulphate of sodium Na,S,O,, or 248 parts of ordinary hyposulphite of soda
(which latter is then deprived of its water of crystallisation by heating at a

page_text: temperature of above 100° C. until dry), and mix it intimately with 90 parts of
oxalic acid from which all water of crystallisation bas also been removed.
To make a bulkier or cheaper preparation we prefer to use in place of oxalic
acid the acid sulphate of soda or potash, or a mixture of the neutral and acid
sulphates of soda or potash such as is obtained as a bye-product of the manufacture
of nitric acid from salpetre. The proportions of the ingredients that we find most
advantageous are 210 parts of acid sulphate of soda or 240 parts of acid sulphate
of potash to 158 parts of thiosulphate of sodium. Or we may employ cream of
tartar and other solid acid substances in place of those above mentioned.
To prepare an arsenical powder we further add to any one of the foregoing
mixtures arsenic acid or a soluble salt of arsenic, varying the proportions
accordingly as more or less sulphur or sulphide of arsenic is desired in the insoluble
precipitate that results from the addition of water to the powder. For preference
we employ arsenate of soda, adding one part of arsenate to two parts of sodium
thiosulphate in the mixture. In all these operations it is equally necessary to
provide against the incorporation of water in any form into the mixture, if necessary
by carefully drying the several ingredients beforehand.
The sulphur or arsenical dipping powders so prepared may be kept for a
considerable length of time without deteriorating or losing their solubility if
ordinary precautions against damp are taken. When dissolved in water the wash
is ready for immediate use and remains efficient for several hours. These
sulphur or arsenical sheep-dips are suitable for employment with coal-tar
sheep-dips.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what we
claim is:
1. The manufacture of soluble sulphur or arsenical powders substantially as above
described by mixing together thiosulphate of sodium, Na,S,O,, or other soluble
sulphuretted sulphates, with solid acid substances such as oxalic acid, acid sulphate
of soda or potash, or cream of tartar, which in the presence of water cause the
decomposition of the above sulphur compounds and deposition of sulphur, with or
without the addition of arsenic acid or soluble salts of arsenic, but all of which
ingredients are before admixture free from moisture or water in any form
whatsoever, including eveu water of crystallisation, substantially as above
described.
2. As novel products sulphur or arsenical powders prepared substantially as
above described which are soluble in water, but the solutions of which after a
longer or shorter time, according to the temperature or concentration of the
solutions, liberate sulphur or sulphide of arsenic, or a mixture of sulphur and
sulphide of arsenic, in a finely divided insoluble condition, substantially as above.
described.