IMPROVE- MENTS IN THE PREPARATION OF SOLLS, TO PROMOTE GENERAL VEGETATION AND PREVENT INSALUBRIOUS OR UNHEALTHY EXHALATIONS FROM MANURES PLACED THEREON
Year: 1866

page_text: LETTERS PATENT to Thomas Spencer, of Euston Square, in the County
of Middlesex, Chemical Engineer, for the Invention of "IMPROVE-
MENTS IN THE PREPARATION OF SOLLS, TO PROMOTE GENERAL VEGETATION AND
PREVENT INSALUBRIOUS OR UNHEALTHY EXHALATIONS FROM MANURES PLACED
THEREON."
Sealed the 3rd July 1866, and dated the 24th January 1866.
PROVISIONAL SPECIFICATION left by the said Thomas Spencer at the
Office of the Commissioners of Patents, with his Petition, on the
24th January 1866.
I, THOMAS SPENCER, of Euston Square, in the County of Middlesex,
Chemical Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE PREPARATION OF SOILS, TO PROMOTE GENERAL VEGETATION
AND PREVENT INSALUBRIOUS OR UNHEALTHY EXHALATIONS FROM MANURES PLACED
THEREON," to be as follows:-
This Invention consists in the application to soils of a ferruginous sub-
stance well known as magnetic oxide of iron, or mineral or artificial com-
pounds or mixtures of the same, for the purposes of promoting the growth
and improving the character of general vegetation, and also to prevent the
insalubrious exhalations arising from sewage or other such. foetid or offensive

page_text: manures when applied to the land. The conditions and proportions in
which this ferruginous substance ought to be applied to soils for the above
purposes I here give as derived from such experiments as I have been enabled
to make on a relatively limited scale during several
years.
For the purposes of this Invention I prefer to prepare the required
oxide directly from iron ores, or from such ores or substances as contain
iron, or from such refuse substances or mixtures as are derived therefrom.
In these I include the ferruginous refuse of spent pyritic ores, or ferru-
ginous clays, or iron or steel filings, or any ferruginous sand or refuse matter
which may be converted in whole or in part to the oxide required for the.
purposes of this Invention. In proceeding to its manufacture from
any of these substances it is necessary in the first place to mix along
with them certain proportions, herein-after to be named, of matter which
shall contain carbon. The mixture is then to be subjected to a low
red heat in a closed fire-brick chamber, oven, or retort until the preparation
of the oxide is considered to be complete. The door of the oven or
retort must be closed or luted up during the process, and it is requisite to
have a half or three-quarter inch aperture or pipe with a stop-cock in the
door or other convenient part of the oven or retort to permit of the escape
of any gases or steam arising from the mixture during the operation.
The matter to be mixed along with the ore may be such readily carbon-
ized substances as wood chips, peat, sawdust, granulated coke, or charcoal,
cach of which may be used together or separately; even ordinary coal, if
other carbonaceous matter cannot be conveniently had, may be used; but
to prevent the reduction of the oxide to the metallic state during the pro-
cess, that containing the smallest proportion of bitumen or sulphur, such as
anthracite, is preferable. The necessary quantity of carbonaceous matter
depends much on the nature of the ore or refuse from which it is intended
to prepare the oxide; but as a rule I prefer to use sawdust or peat in pro-
portions of from 10 to 14 per cent. of the weight of the peroxide or ferru-
ginous matter about to be treated. The raw ore or ferruginous matter
previous to being mixed with the carbonaceous matter ought to be broken
into pieces and granulated. The mixture is then to be gradually subjected
to as much heat in the before-mentioned oven or retort as shall be sufficient
to drive off that portion of its oxygen which prevents its being fully
attracted by the magnet. The retort containing the mixture of carbonaceous
and ferruginous matter is now to be brought to a dull "cherry red" heat,.
and kept at this temperature from 6 to 10 hours, the difference in time
depending on the original state or granulation of the ferruginous material;

page_text: state..
but care must be taken that the heat should not be so great at any stage
of the operation as to cause the reduction of the oxide to the metallic
When the heating operation shall be considered complete the newly
formed magnetic oxide must be suffered to cool before admitting air, or it
may be discharged into water whilst red hot. Before its application to the
soil it ought to be reduced by grinding to a state of powder, such as that
of fine gunpowder or coarsely ground flour. The proportions in which the
prepared oxide is to be spread over the land vary from, say, 5 cwt. to 3
or more tons per acre. The oxide after being spread over the soil ought to
be harrowed or raked into it (as practised on the sowing of seeds), though
not deeply. When the soil has received its full quantity, taking the nature of
the crop into consideration, no further addition of oxide will be necessary.
In addition to its quality of rotting vegetable substances and promotions
their formation into manure and thence to carbonic acid, this oxide also
promotes the formation of ammonia by causing atmospheric nitrogen to
combine with such hydrogen as is produced in the soil. Although I have
found the ferruginous oxide herein named to be the most powerful agent
to promote vegetation, kindred oxides of other metals, such as those
of nickel, cobalt, and manganese, I also find to possess similar properties,
but which from their greater cost and lower power are less likely to
be used for the purposes of this Invention than the ferruginous oxide I
herein name.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Spencer in the Great Seal Patent Office on the
24th July 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
SPENCER, of Euston Square, in the County of Middlesex, Chemical
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her. Letters
Patent, bearing date the Twenty-fourth day of January, in the year, of our
Lord One thousand eight hundred and sixty-six, in the twenty-ninth.
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. Thomas Spencer, my executors, administrators, and assigns, or such
others, as I, the said Thomas Spencer, my executors, administrators,, and

page_text: 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 "IMPROVEMENTS IN THE PREPARATION
OF SOILS, TO PROMOTE GENERAL VEGETATION AND PREVENT INSALUBRIOUS OR
UNHEALTHY EXHALATIONS FROM MANURES PLACED THEREON," upon the con-
dition (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
ent Office within six 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
performed, to be particularly described and ascertained in and by the
following statement (that is to say) :-
General objects and nature of this Invention. It has long been
observed that less manure is required by the soils of some districts than
others, but as the most remarkable instances are observed within or near
the tropics, the causes of this natural state of fertility are considered to be:
due more to high temperature and climate than to any inorganic peculiarity
of soil.
The most notable example of fertility unaided by manure is found
in Egypt, and although its continuance is generally attributed to organic
matter belonging to the mud brought by the Nile during its overflow, yet
from the analyses of numerous specimens of it taken at various points
during such periods (including some from above the junction of its
branches at Kartoum) I arrive at the conclusion that the great fertility of
this soil is not due to this cause, the organic matter in the water itself"
being less than is usually found in that supplied to this metropolis
(London), whilst a bare trace only is contained in its sedimentary mud.
It thus appeared evident that Egyptian fertility was not due to pre-existing
organic matter, whilst the same rendered it highly probable that the cause-
would be found in some unrecognised inorganic principle inherent to the
soil. This opinion was considerably strengthened on considering that a
state of things exists in several districts of other countries, but without any
connection with the overflow of a river. Even in Great Britain the soils

page_text: of several districts are essentially more fertile than others, irrespective of
the quality or quantity of the manure used on them. It may be necessary.
to observe that apart from organic matter the best soils are almost in-
variably composed of four mineral substances, viz., silica, alumina, lime,
and iron, each existing as oxides of their respective metals. Although
other bodies such as manganese and magnesia are found, they do not play
any very important part in the economy of vegetation, except where they
occasionally act as natural substitutes in the absence of either of the others.
On these grounds it seemed reasonable to expect that the principle of
fertility would be found among the pervading substances, especially as
phosphoric acid and potash are not found in unusual quantity in any of
the most fertile soils in question. It was whilst engaged in an enquiry in
another direction that I found that impure water was deprived of organic
matter by the action of magnetic oxide of iron, and that the said matter
became changed into carbonic acid by the same agency. Though both
facts were of great importance in reference to the object on which I
was then engaged, yet it appeared evident that the latter one would afford
a key to the problem as to the causes of their exceptional states of fertility.
The presence of this oxide in Egyptian soil might be accounted for by
the continued disintegration of trap and similarly constituted rocks which
are said to exist in the upper regions of Central Africa, and which usually
contain magnetic oxide of iron to the amount of eighteen or twenty per
cent. This, with the other disintegrated constituents of trap, would form
the mud held in suspension by the water, and so be brought down and
deposited on the level grounds during the periods of annual. overflow.
The existence of a similar oxide in other fertile districts, which are chiefly
volcanic, would be easily accounted for, as their soil is known to be com-
posed of disintegrated lava, the iron of which is chiefly in the state of
magnetic oxide. In accordance with these views several experiments were
made with soils artificially composed of washed sand and various propor-
tions of prepared magnetic oxide, but from which manure in the ordinary
sense was withheld. The results were so highly favorable as to lead me
to procure a number of specimens of soil from Egypt, which were. taken
from several places in that country and at various depths. Chemical
examination subsequently showed that all of them contained magnetic oxide
in very nearly the proportions known to belong to trap rock.or to lava. It
was remarked, however, that those specimens which were taken from the
greatest depths contained the largest proportions of this oxide, a fact which

page_text: renders it probable that in the earlier periods of the history of this country
its soil was even more productive than at present, and that the overflow of
the Nile formerly brought with it a larger per-centage of this oxide than
in our days.
Rationale of the action of this oxide in promoting vegetation.-When
seeds are placed in the earth. their inherent vital powers are called into
activity by moisture and heat. This, which may be termed the foetal state
of germination, is sustained at the expense of the matter of the seed itself,
though as soon as this matter is exhausted and the young roots are thrown
out the plant is then compelled to derive its food from such organic matter
'as may liappen to be present in the soil, but unless this matter is in that
decayed or rotten state which constitutes manure its subsequent conversion
into carbonic acid is not sufficiently rapid for the wants of the young
plant, as carbon can only be assimilated by it in the form of this acid. It
is therefore reasonable to conclude that any substance which shall thus
hasten the decay of dead matter, and at the same time shall be without
power to act similarly on the root itself so long as its vitality is sustained,
the presence of such a body in the soil will be of great manurial value.
Thus the decay of the cereal or other roots which it is the custom to leave
in the ground is hastened by the agency of this oxide as well as the ulti-
mate conversion of their matter into the carbonic acid necessary for the
growth of the next crop, whilst woody or other raw undecayed matter may
be put in the soil with the certainty of its being rapidly converted into
this acid. Such then is the theory of the action of this peculiar oxide of
iron, and which beyond all doubt plays an important part in most soils,
none being found in which a small proportion of it may not be detected
among the other but less active ferruginous matter. Its existence in
Egyptian soil will thus fully account for the general salubrity this country
has enjoyed at almost every period of its known history, as well as the com-
parative purity and "sweetness" of its river water, which is even celebrated
for these qualities in Holy Writ. It may be added that without the exis-
tence of this magnetic substance in its soil, constantly operating to change
decaying organic matter into carbonic acid, the exhalations arising from
the moist mud at the termination of the inundation would be pestilential.
Where, therefore, sewage or other foetid or offensive matters shall be
applied as manure to land in our own country the application of a similar
oxide will, in addition to its manure making value, be attended with equally
salubrious results.

page_text: mag:
Description of the Invention.-I hereby declare these improvements to
consist in the application to soils of a ferruginous substance known as "
netic oxide of iron," or other mineral or artificial compounds or mixtures of
the same, for the purposes of promoting the growth and improving the
character of vegetation generally, and also to prevent the insalubrious exha-
lations arising from sewage or. other such offensive manures when applied to
the land. The conditions and proportions in which this ferruginous sub-
stance ought to be applied to soils for the above purposes I here give as
derived from such experiments as I have been enabled to make on a rela
tively limited scale during several years.
For the purposes of this Invention I prefer to prepare the required
oxide directly from iron ores, or from such ores or clays as contain iron, or
from any refuse substances or mixtures derived therefrom and which shall
contain iron. In these I include the ferruginous refuse of spent pyritic
ores, or ferruginous clays, or iron or steel filings, or any ferruginous sand
or refuse matter which may be converted in whole or in part to the
oxide required for the purposes of this Invention. In proceeding to its
manufacture from any of these substances it is necessary in the first place
to mix along with them certain proportions, herein-after named, of matter
which shall contain carbon. The mixture is then to be subjected to a low
red heat in a closed fire-brick or iron chamber, oven, or retort, until the
preparation of the oxide is considered to be complete. Such retorts or
ovens may be used for this purpose as are commonly used in the manu-
facture of illuminating gas. The door of the oven or retort must be closed
or luted up during the process, as in the manufacture of gas, and it is
requisite to have a half or three-quarter inch, aperture or pipe with a
stop-cock in the door; or in other convenient part of the oven or retort to
permit of the escape of the gases or steam from moisture arising from the
mixture during the operation. The matter to be mixed along with the
ore may consist of such readily carbonized substance as wood chips, peat,
sawdust, granulated coke, or charcoal, each of which may be used together
or separately; even ordinary coal, if other carbonaceous matter cannot be
conveniently had, may be used; but to prevent the reduction of the oxide
to the metallic state during the process coal containing the smallest pro-
portion of bitumen or sulphur, such as anthracite, is preferable. The
necessary quantity of carbonaceous matter depends, much on the nature
of the ore or refuse from which it is intended to prepare the oxide, but as
a rule I prefer to use sawdust or peat in proportions of from ten to fourteen
per cent. of the weight of the peroxide or ferruginous matter about to be

page_text: treated. The raw ore or ferruginous matter previous to mixing with the
carbonaceous matter ought to be broken into pieces and granulated. The
mixture is then to be gradually subjected to as much heat in the oven or
retort as shall be sufficient to drive off that portion of its oxygen which
prevents its being fully attracted by the magnet. The retort containing
the mixture of carbonaceous and ferruginous matter is now to be brought
to a dull cherry red" heat and kept at the same from six to ten or
twelve hours; the difference in time depending on the original state or
granulation of the ferruginous material. Care must be taken that the heat
should at no stage of the operation be so great as to cause the reduction of
the oxide into the metallic state. When the heating process shall be con-
sidered complete, the newly formed magnetic oxide must be suffered to
cool before admitting air, or it may be discharged into water whilst red
hot in the manner practised at gas works in cooling the coke from the
retorts whilst in a state of redness; I find the best mode of ascertaining the
completeness of the change from ordinary inert peroxide into magnetic
oxide to be its perfect state of blackness, and that every particle shall be
attractable by the magnet. Before its application to the soil it ought to
be reduced by grinding to a state of powder, such as that of fine gunpowder
or coarsely ground flour. The proportions in which the prepared oxide is
to be spread over the land vary from five hundredweight to three or more
tons per acre (this difference arises from the variable nature of the soil or
the character of the crop intended to be grown in it). However the
necessary quantities are best determined by previous analyses of the soil,
but as my own practice does not extend to experiments made on very large
surfaces experience will easily determine these points with the requisite
exactitude. The oxide after being spread over the soil ought to be
harrowed or raked into it (as practiced in the sowing of seeds), though not
too deeply. When the soil has received its full quantity, taking the nature
of the crop into consideration, no further addition of oxide will be
necessary. In addition to its quality of rotting decayed vegetable sub-
stances and promoting their formation into manure, and hence to carbonic
acid, this oxide also promotes the formation of ammonia in the soil by
causing atmospheric nitrogen to combine with hydrogen. Although I
have found the ferruginous oxide herein named to be the most powerful
agent to promote vegetation, kindred oxides of other metals, such as those
of nickel, cobalt, and manganese, are also found to possess similar pro-
perties, but which from their greater cost and lower attractive power are
less likely to be of value-for the purposes of this Invention than the ferru-

page_text: ginous magnetic oxide. To prevent misapprehension it may be necessary
to state that natural magnetic oxide in its crystalline state is comparatively
inoperative. It is, therefore, not sufficient that it should be magnetic, but
that it should also be porous or cellular, to allow it to secrete the oxygen
necessary to the formation of carbonic acid.
Having to the best of my present knowledge thus described the nature
of my said Invention, I now state the extent of my claim in regard thereof
to be for this first application of the so-called magnetic oxide or ferroso-
ferric oxide, or indifferently protoxide of iron, alone or in mixture, or in
chemical combination with any other body, such as carbon or alumina, to
the agricultural or the sanitary purposes named herein.
In witness whereof, I, the said Thomas Spencer, have hereunto set my
hand and seal, the Twenty-third day of July, in the year of our
Lord One thousand eight hundred and sixty-six.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
THOMAS SPENCER. (L.s.)