IMPROVEMENTS IN THE PRODUCTION OF SULPHUROUS ACID GAS FOR MEDICINAL, SANITARY, AND ECONOMIC PURPOSES, AND IN THE APPLIANCES USED THEREFOR.
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by Francis Thomas Bond at the Office of
the Commissioners of Patents on the 8th December 1876.
FRANCIS THOMAS BOND, of Gloucester, in the County of Gloucester, Doctor of
Medicine. IMPROVEMENTS IN THE PRODUCTION OF SULPHUROUS ACID GAS FOR
MEDICINAL, SANITARY, AND ECONOMIC PURPOSES, AND IN THE APPLIANCES USED
THEREFOR.'
The object of this Invention is to provide a means for the rapid generation of
sulphurous acid gas, either in the free form or in solution, in order that it may be
supplied to the public in a more economical and convenient for than hitherto, and
thus facilitate its employment as an antiseptic agent for medicinal, sanitary, and
economic purposes.
Hitherto it has been the custom to supply this agent for such purposes in the
form of a solution, obtained by saturating water or a solution of some salt with the
gas, produced by any of the methods described in ordinary chemical works. The
disadvantage of this method is that the cost of supplying the gas to the public in
this form is rendered excessive in consequence of the large bulk of liquid with
which it is thus unavoidably associated.
In order to remedy this disadvantage I avail myself of the decomposing properties
possessed by certain acids and acid salts of the alkalies and alkaline earths to
decompose the salts of sulphurous and hyposulphurous acids when mixed in solution
with them, thus forming a solution of sulphurous acid in combination with the saline
elements of these salts. For this purpose I prefer to take the salt known as
common alum, consisting of the sulphate of aluminium combined with either the
sulphate of ammonium, sodium, or potassium, and the hyposulphate of sodium. If
these salts are introduced into water they will as they dissolve act upon one another,
the weakly combined acid of the alum attacking the byposulphate and liberating
sulphurous acid and free sulphur. In this way a solution of sulphurous acid may
be obtained of any required strength according to the amount of water and salts
used. Or if the acid be required in the free gaseous form it is only necessary to
mix the salts together in a pulverulent form and slightly moisten them, when it
commences at once to be evolved and will continue coming off for a considerable
time. This will be found a very convenient way of procuring it for the purpose of
disinfecting rooms.

page_text: In order to increase the decomposing power of the alum I combine with it a
certain additional amount of sulphuric, acid by reducing the salt to a fine powder
and then mechanically incorporating the acid with it in the proportion by weight
of one part of the strongest oil of vitriol of commerce to eight parts of the salt.
As it is impossible to keep the acidified sulphate thus prepared and the hypo-
sulphite mixed with one another even in the solid form without their acting upon
one another I prepare them for the use of the public in vessels so divided that the
two salts can be kept separately and can be easily extracted or discharged in the
proportions which are necessary in order to obtain the most satisfactory results.
These proportions are equal quantities of the hyposulphite and of the alum acidified
as above described.
I do not limit the method which I have thus described for the convenient pro-
duction of sulphurous acid for economic and other purposes to the use of the two
salts which I have specified above. Any alkaline or earthy hyposulphite or sulphite
may be employed in the place of hyposulphite of sodium, and instead of alum I
may use either of the alkaline sulphates, or the sulphate of aluminium, or any of
the vegetable acids which are available for use in the solid form, such as oxalic or
tartaric acids.
The essential features of my method are,-
First. That the salts employed are used in a dry form so that they can be applied
as sources of sulphurous acid by mixing them together in proper proportions in the
presence of water.
Second. The use of an artificially acidified salt or of a solid vegetable acid for the
purpose of decomposing the hyposulphite or sulphite employed.
And, Third. The supply to the public of the salts thus selected in vessels which
are so divided that they can be kept separate and thus stored in a portable form for
any length of time ready for immediate use without decomposition.