CERTAIN IMPROVEMENTS IN THE PURIFICATION OF WATER AND OTHER FLUID AND GASEOUS BODIES
Year: 1857

page_text: LETTERS PATENT to Thomas Spencer, Analytical Chemist, of 21, South-
ampton Place, Euston Square, London, for the Invention of "CERTAIN
IMPROVEMENTS IN THE PURIFICATION OF WATER AND OTHER FLUID AND
GASEOUS BODIES."
Sealed the 18th December 1857, and dated the 19th June 1857.
PROVISIONAL SPECIFICATION left by the said Thomas Spencer at the
Office of the Commissioners of Patents, with his Petition, on the
19th June 1857.
I, THOMAS SPENCER, Analytical Chemist, of 21, Southampton Place, Euston
Square, London, do hereby declare the nature of the said Invention for
"CERTAIN IMPROVEMENTS IN THE PURIFICATION OF WATER AND OTHER FLUID AND
GASEOUS BODIES," to be as follows:-
For the purification of water or other fluid or gaseous body I use certain
iron. ores containing protoxide of iron. These may be applied alone, or in
a crushed or powdered state along with sand, gravel, or other commonly
known filtering material, the water or other fluid or gaseous body being made
to pass over or percolate through the same.
.
The ores to which I give preference are those which contain the largest
proportions of protoxide of iron, that known as the spathose iron ore being
thereby most available.
This ore may be used in its natural state, being that of a carbonate of this
protoxide, but in ordinary cases I prefer to use it after the carbonic acid is
driven off by heat.

page_text: For the above purposes of purification I also use the iron ores known
in their native state as "magnetic ores," and which contain protoxide of
iron, preference being given to those which contain the largest proportions
of protoxide.
For the above purposes of purification I also use the substance known to -
mineralogists as chlorite, and which contains variable proportions of protoxide
of iron. This substance is found naturally as "compact amorphous chlorite,"
'chlorite slate," and "earthy chlorite," in any of which states it may be used
either alone or along with the ordinary and well-known materials used in
filtration.
This Patent is for this first application of protoxide of iron to the above
purposes of purification, and for the application to the same of any of the
substances herein named which contain the same oxide.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Spencer in the Great Seal Patent Office on the
19th December 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
SPENCER, Analytical Chemist, of 21, Southampton Place, Euston Square,
London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of June, in the year of our Lord One
thousand eight hundred and fifty-seven, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Spencer, Her special licence that I, the said Thoms Spencer, my
executors, administrators, and assigns, or such others as I, the said Thomas
Spencer, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "CERTAIN IMPROVEMENTS IN THE
PURIFICATION OF WATER AND OTHER FLUID AND GASEOUS BODIES," upon the
condition (amongst others) that I, the said Thomas Spencer, my executors
or administrators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within six

page_text: calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Thomas Spencer, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
The said Invention consists in a method of effecting the purification of
water and rendering it wholesome, and fitted for all domestic and manu-
facturing purposes, and, also for depriving alcoholic fluids of certain impurities
which are incident to them in the process of distillation. For the better
understanding the nature and character of the improvements embodied in
the first part of my said Invention the following preliminary statement is
necessary:-
Improved drainage, and increasing urban population, have in a number
of cases caused the inhabitants of large towns in these kingdoms, as well
as persons connected with manufactures, which require colorless water to
collect for their supply, that which has fallen on the surface of rural districts,
or that of streams issuing therefrom. As the purest water under these
circumstances is obtained from districts the least cultivated, those which are
covered with bare moorland vegetation are generally resorted to. It is
known, however, that water so obtained, though in other respects pure and
soft, is more or less colored by the juices of the vegetation on which it has
previously fallen as rain. This tinge of color, together with that derived from
the peat, on from patches of peaty earth which are often found in such districts,
operates as an objection to its use for many domestic and some manufacturing
purposes. It is also known that water after its employment in several
manufacturing and other operations becomes thereby so much impregnated
with coloring matter as to render it unfit for further use. It is also known
that by the decomposition of organic matters water becomes tainted with
deleterious gases, such as those known to chemists as sulphide and phosphide
of hydrogen, or perhaps the same are better known as sulphuretted and
phosphoretted hydrogen. These, as well as ammoniacal combinations arising
from similar causes, are often found in water where no tinge of color is
observed.
The first part of this Invention is for the purification of such waters from
any tinge of organic color or deleterious gaseous body. To effect such
purification I use an oxide of iron, either in lumps or granulated by crushing
to the state of ordinary sand, though the same may be used in a state of
powder. It is to be remembered, however, that the rapidity of the mere

page_text: filtering operation depends much on the relative coarseness of the oxide
employed. This substance may be used in the above states by itself, but I
prefer to use it when mixed with variable proportions of sand or gravel, or
with any material through which water is ordinarily passed, to deprive it of
suspended matters. To remove from water, therefore, any of the above-
named impurities, or all of them, I proceed, in the first place, as if mechanical
filtration alone were to be effected. For example, the purifying operation is
performed in a filtering vessel, a filtering tank, or "filtering bed," either of
which is made to receive the ordinary filtering media of sand and gravel, the
only difference being, that in my Invention I mingle with every twenty parts
of the top layer of sand from one to two and a half parts by measure of
oxide of iron, the quantity of the latter depending on the relative impurity or
color of the water to be treated, as well as the quality of the oxide itself;
besides which, should the particles of a given quantity of oxide be in a
relatively finer state than ordinary sand, less of the former is necessary,
though it must be remembered that the process of enfiltration will then proceed
with less rapidity than if the particles of oxidé were in a coarser state. I am
of opinion, however, that the exact quantity of oxide requisite to be employed
in these operations cannot be practically laid down with greater precision;
inasmuch as the purifying quality. of this substance in its natural state is in
itself subject to variation. A given quantity, for example, of that derived
from the mines of one district will operate more effectually than a similar
bulk from another. Indeed a slight variation is in this respect found in
different parcels derived from the same mine; as one of them may contain a
larger proportion of inert peroxide or carthy matter than the other; pre-
liminary trials, therefore, will in some cases be necessary. In all ordinary
ones, however, quantities ranging within the above limits (though I do not
confine myself to them) will render impure water instantaneously colorless
and free from all odour.
Where the extent of the operations are commensurate with the supply of a
town or manufactory, the top layer of mixed filtering sand and oxide ought to
be from twelve to eighteen inches in thickness, all beneath may then consist
of the usual layers of coarser sand, gravel, or shingle, the thickness of which,
being indifferent to this Invention, may be regulated at pleasure. It will thus
be seen that the only alteration proposed to be made in the ordinary filtering
media is the addition of the above proportions of oxide to the sand or
substance usually employed in mechanical filtration.
In respect to domestic filters, or those on a relatively small scale, the
proportions of oxide to sand may be advantageously increased, as a thickness,

page_text: of twelve or eighteen inches of filtering media in such cases is inconveniently
large. If in these cases, therefore, the proportions of oxide to sand be
increased to a third, or to equal parts of each, four or five inces of filtering
media will be found to effect as perfect purification as if a thicker media
containing less oxide were used. It will, however, be sufficiently obvious
that intermediate proportions of the oxide may be employed, varying, if
necessary, with the size of the filtering vessel and the state of the water
to be purified.
Though I have named sand or gravel to be mixed with the oxide as being
readily procured, yet the said oxide may be used in combination with other
filtering media, such as charcoal, coke, or porous stone, whether the latter be
natural or artificial. Such stone may be used in a crushed state, or in slabs,
or it may be hollowed into vessels, and the purifying oxide placed within the
same, or exteriorly thereto. Should the oxide whilst in use become in any
degree inert by reason of filthy matters in very foul water, the same may
be cleansed by washing, or it may be revivified by calcination. According
to my experience, however, inertness from such a cause is seldom likely
to happen. In proof of which I may state, that during the preceding six
months experiments have been made with very impure and highly colored
water almost daily, whilst other experiments have been continued for more.
lengthened periods, but in none of them has any renewal of the ferruginous
filtering media taken place, nor in any case have I been able to observe a
diminution of its powers of purification. In a legal document, designed as a
guide for practice only, it may be considered in some degree out of place to
occupy any part of it in defining theoretical causes of phenomena; but as the
explanation I have to offer of the physical cause of this process of purification
will render its practice much better understood, the following few words on
the subject may not be unnecessary.
Observation and experiment have led me to the conclusion that oxide of
iron containing less oxygen than the per or sesqui-oxide possesses a physical
power to attract atmospheric oxygen to its surface. Such oxide is generally
known as the "magnetic oxide, from the power exercised over it by the
magnet. This oxide, when found in combination with other substances, as
in the spathose ore, consists of one equivalent of oxygen to one of iron.
but when found uncombined, the mass is said to possess four equivalents of
oxygen to three of iron. The sesqui or per-oxide, on the other hand, which
is not magnetic, consists of three equivalents of oxygen to two equivalents of
iron; this latter oxide, however, is not available in this Invention. Although
as I have stated the former oxide thus attracts oxygen to its surface, yet at

page_text: ordinary temperatures, or while moist, it does not possess the power possessed
by iron under similar circumstances of entering into chemical combination
with this atmospheric gas. Though thus unable to combine with any addi-
tional oxygen, yet, in common with a few other substances possessed of similar
properties in relation to this gas, this oxide possesses another, or it may be an
extension of the same attractive power, which has the effect of inducing the.
oxygen, in contact with its surface, to enter into chemical combination with
certain other bodies with which it is brought into contact.
It is well known that organic coloring matter, as well as most gaseous
impurities, when in water, or in a state of moisture, are rendered perfectly
neutral on combining with atmospheric oxygen; in other words, they become
bleached and purified by the combination. It is well known, however, that in
the absence of an inducing force, such as that possessed by this oxide, the
atmospheric process is in practice a slow one, just as the analogous process of
natural bleaching is slow as compared with modern processes. When, there-
fore, impure water is made to pass through filtering media containing this
oxide, the atmospheric oxygen clinging to its surface is, in virtue of this
peculiar power, induced to enter into instantaneous chemical combination
with the impurities found in the water. Although known to belong to some
other bodies, this peculiar property, as far as I know, has not hitherto been
recognised as appertaining to oxide of iron. By chemists the property is
termed "catalysis," which conveys the fact of chemical combination being in-
duced in two bodies by reason of contact with a third, which third is not itself
acted on. I may mention that I find the protoxides of manganese, nickel, and
cobalt to possess similar purifying properties, though they are not exercised
nearly so powerfully as in the case of the ferrugineous oxide. Without
binding myself in all respects to its correctness, this explanation of the
process is strongly corroborated by the conditions necessary to be observed
in practice. For example, should the top layer of moist sand and oxide, in the
course of the process, be exposed to the atmosphere for a few seconds only,
purification will proceed subsequently with greater rapidity than before. An
interval of no longer duration, therefore, is amply sufficient to re-cover the
surface of the oxide with a fresh coating of oxygen. On the other hand,
should the top layer be submerged to a considerable depth, and the oxide
become thereby unable to attract a fresh supply from the atmosphere,
purification is then less perfect. In such a case no other oxygen is
available but that belonging to the air contained in the water. Under
these circumstances, should the water be very impure, the oxygen contained
in it will scarcely be found sufficient for its purification. At the same time;

page_text: with water of no great impurity, the oxygen mingled with its intersticial
air will be found sufficient to effect its purification, especially should the
top layer of sand and oxide be of the greater thickness above named.
For these reasons I prefer, as a general rule, that the water which enters the
filtering tank should not be permitted to accumulate to a greater height than
two or three inches above the purifying media; this condition may be easily
regulated on any required scale by keeping the aperture of discharge rela-
tively largely than that admitting the water to be purified. At the same time
no claim is here made for any mode of filtration, but only for the application
of the new material to the purifying purposes herein named. Though it is
probable that further experience may arrive at improved methods of producing
the same effects by means of this oxide, the mode here described, however,
which differs little from that practised in ordinary filtration, I at present
believe to be the best. By following the process here described very impure
and highly-colored water becomes instantaneously possessed of all the purity
and freshness of spring water. Moreover, there can be little doubt that it is
to the agency of the same ferruginous oxide we are so much indebted for 'the
natural process, whereby impure water from the surface becomes converted
into the spring water of the well.
:
In the second place, with respect to the purification of other fluids. It is
well known that newly distilled spirituous liquors, as whiskey, rum, brandy,
or such other alcoholic fluids, are, when drank in such a state of newness;
especially injurious to the human system. This arises because of the presence
of certain essential bodies in a semi-gaseous state, which are made or less
incidental to the distillatory process, though especially so when the spirit is
distilled from inferior materials. Chemists have not yet strictly determined
the composition of these deleterious compounds, but it is known their effects
are neutralised by oxidation. In practice the oxidising process is virtually
performed by storeing the spirits for indefinite periods in wooden casks or
other vessels; which are not beyond the influence of atmospheric oxygen. 'For
the purpose of correcting these injurious properties in shorter periods, I cause
by my Invention the newly distilled spirits to be passed or filtered through a
layer of the before-mentioned oxide of iron, which may or not be mixed with
any other filtering media, as in the general manner described as regards water:
In the purification of spirits, however, I find, as a rule, that the best effects are
produced when the filtering media is composed of equal parts of the oxide and
the purest sand, though pounded glass or charcoal may be substituted for the
two latter. The thickness of the media in these cases may vary from one to
three or four feet, but which will altogether depend on the amount of impurity

page_text: to be discharged from the spirit, or the spirits may be passed through the
media a second or even a third time. .
I further recommend that the spirit to be purified should be allowed to pass
through the filter at intervals, (that is to say) as soon as the filtering media
becomes saturated with the fluid to be purified no addition should be made
until the first charge has reached within about an inch of the bottom of the
filtering layer, and so to continue during the process. The required depth in
this case may be readily ascertained by having a glass gage attached to the
outside of the filtering vessel, which will communicate with the fluid within.
The increased thickness of the layer of filtering media now recommended is to
prevent the necessity for having a large surface, which would promote the
wasteful evaporation of the spirit to be purified. This process, however, is
best conducted in covered vessels. The oxide of iron which I prefer to use
for the purposes of purification herein enumerated is that obtained by cal-
cining the natural protocarbonate of iron, which substance is known to
mineralogists as the "spathose ore." "Whilst in combination with its carbonic
acid, the oxide in this ore is composed of one equivalent of oxygen to one of
iron. After the gaseous acid is driven off by heat a black oxide remains,
which by subsequent experiment indicates a somewhat higher degree of
oxygenation in the whole mass, but whether the calcined oxide consists of the.
protoxide with some peroxide in a state of combination, or merely in a state of
mixture, is, a question of little practical moment as regards this Invention.
Though I prefer to use the oxide obtained from the spathose ore as being the
purest, that fund naturally as "magnetic iron ore is also available. Available
oxide for the same purpose is also obtained by calcining the well-known
hematite ore. This operation is best performed by previously reducing the ore
to a granular state and mingling it with carbonaceous matter, such as coke or
charcoal; when calcined sufficiently it becomes magnetic. By a smilar pro-
cess of calcination ferruginous sands are likewise made available. Those
sands, however, which contain oxide of iron in the magnetic state do not
require to be calcined. The smithy scales derived from the forging of iron
are in like manner available, as they chiefly consist of an oxide which is
attracted by the magnet. The loam or sand which has been used for mould-
ing cast iron is in like manner available as a purifying media for the purposes
of this Invention. This substance after use contains a large proportion of
oxide of iron, of the character required for purification; it is best cleansed
from previous impurity by calcination. The mineral substance known as
cholorite, which contains a large per-centage of protoxide of iron in combination,
is also available for the same purposes of purification. This substance is found

page_text: as a greenish slate as well as in amorphous masses; it is also found granular
as in "the green sand;" its purifying power is in several instances consider-
ably increased by calcination. It may be scarcely necessary to mention, that
where oxide from the spathose ore cannot be conveniently procured, the other
substances herein named containing the same oxide may be severally or
collectively substituted, and also that the spathose ore before calcination
possess considerable powers of purification, though inferior to its oxide alone.
The ore in this state, therefore, if the water is not of a very impure character,
may be used for its purification. Oxide for the purposes of this Invention may
be obtained artificially, that is, by precipatation from a ferruginous salt in the
first place, and subsequently by calcination, though from its extreme state of
cimminution oxide of this character is not preferred. The value of the oxide
for this Invention is best determined by the magnet. As a rule, a mass of
oxide which is the most attracted by the magnet is the best. The oxide of
iron which in the mass contains less oxygen than the peroxide is indifferently
termed the protoxide and the magnetic oxide, but were this a strictly correct
chemical distinction, which is doubtful, yet as the mass is magnetic and con-
tains less than the per on sesqui-oxide (which is not available), I prefer in
this Patent to speak of this oxide as magnetic protoxide of iron, which,
independently of any considerations of theoretical composition, alike designates
its most remarkable physical property, and, according to chemical nomen-
clature, sufficiently indicates the relation it bears to the peroxide, which is the
only other oxide known to practice.
Having thus described the nature and character of my Invention, I wish it
to be understood that what I claim in this Patent is the purification of water
aud the other fluids herein-before mentioned by means of the ferruginous
oxide just described. I further claim the same oxide, if used for the same
purposes, alone or in combination with any other filtering media. I also claim
the same oxide for these purposes as found combined in the mineral or arti-
ficial substances herein named.
In witness whereof, I, the said Thomas Spencer, have hereunto set my
hand and seal, this Nineteenth day of December, in the year of our
Lord One thousand eight hundred and fifty-seven.
THOMAS SPENCER. (L.S.)