Marl. A letter addressed to the Agricultural Society of Jefferson County, Georgia

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MARL.

A LETTER ADDRESSED

TO

THE AGRICULTURAL SOCIETY

JEFFERSON COUNTY, GEORGIA.
BY J. HAMMOND.

(PUBLISHED BY REQUEST OF ©HE SOCIETY.)

Augusta:
PRINTED BY JAMES MeCAFFERTY.
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/ SILVER BLUFF, SO. CA.,
5th January, 1846.

Dear Sir,—

Iembrace the earliest opportunity my other engagements have
allowed me, of fulfilling my promise to comply witha the request of your
Society; to give them such iaformation as [ possess in regard to Marl. I
am happy to learn that an interest in this matter has been excited in your
County, and if in what I am about to say, i shall fail to meet all the inqui-
ries which might be mide, it will a.ford m2 great pleasure to communicate
more fully on particular points, at any time hereafter.

Aware of the strong prejudice existing too generally among Farmers
against every thing new in farming, it may not be amiss for me to begin by
saying, that however-new to us Marling may have been a few years ago,
it is in point of fact one of the very oldest agricultural operations of which
we have any authentic record. Pliny, who wrote during the first century
of our Era, mentions Marl as having been long in use among the Greeks

and also in Gaul and Brittain. He describes pretty accurately the appzar-

ance of all, or nearly all, the kinds of marl now known. He even specifies
the peculiar effects of each on soils, and states the length of time these
effects were supposed to last, which was from 10 to 80 years, according to
the quality of the marl and the land marled. Varro, who wrote a centu

before Pliny, mentions having seen fields in Gaul covered with a ‘white
fossil clay,’’ and also describes several varieties of marl as in common use.

Although these writers, because ignorant of the discoveries of modern
science, made great blunders in attempting to account for the extraordinary
influence exerted by this earth on vegetation, and to discriminate between
its varieties, still it is unquestionable that the “leucargillon’’ of the Greeks,
the ‘“fossicia creta’’ of Varro and the “marga’’ of Pliny, were no other
than the same kinds of marl we find here, and which at this day so many
enterprising farmers, both in Europe and America. are actively and exten-
sively engaged in spreading over their fi: lds, and which have been contin-
uously used for that purpose more or less from the remotest ages. Marl.
ing, then, is certainly no novelty—no untried experiment, that can for a
moment be classed among modern humbugs.

There is no question, however, that the wantof chemical knowledge hasin
time past led to great errors in its application and consequent failures—often to
serious injury from its use. When theelementin marl which vivesit its chief
virtue, and also its certain and its probable chemical action on the soil and its
growth, were all unknown, every new application of it was to some extent an
experiment which might or might not succeed. It is a great proof of its uni-
versal value, that so many succeeded as to maintain its reputation and conse-
quent use. Mr. Ruffin of Virginia, was the first in this country to explain on
scientific principles the true nature of marl, its mode of action, and the proper
manner of applying it, and to carry his theory through the ordeal of suc-
cessful experiment. He is the founder of the marling system among us, for

which he will be long and deservedly ranked among public benefactors. His

4

“ Essay on Calcareous Manure” contains every thing that it is important to
know about marl and marling. Throughout my operations, it has been my
guide, and it is still, I believe, far in advance of any thing that has yet been pub-
lished in any country, on the subject. IJfI thought every member of your
Society would procure a copy ofthat Essay, and peruse it carefully, I might
close my letter here, by earnestly recommending them to doso. It is with
the hope of inducing some of them to do it, as well as to testify my respect
for them, by responding to their inquiry, that I proceed.

Marl, as correctly defined by Mr. Ruifin, and now known in this country,
is Calcareous Earth: that is, earth containing lime. The lime found in
it is united for the most part with carbonic acid, and is therefore called
carbonate of lime. Jt sometimes contains lime in other combinations, as
sulphate and phosphate of lime. Azote, has been found in marl also, and
magnesia is not uncommon. Besides these, it contains sand and clay in
various proportions, and occasionally a green sand highly prized as a
manure on account of its being rich In potash. All of these constituents
are valuable to the farmer. But it is the quantity of carbonate of lime in
it which gives its character to Marl, and by which it is estimated when it is
called rich or poor. |

Nothing is more deceptive in appearance, and the most experienced are
liable to great mistakes, if they attempt to estimate its value by the eye, and
without employing the proper chemical test. There is a rock found in
abundanee in your county, and which is of great value for other purposes,
that has deccived many. It seems to be a mass of shells; but the fact is,
they are only effigies, or casts from which every particle of lime has been
long since washed away, and sand deposited in its place. There is also a
fine, soapy earth, usually ofa pale ash colour, though sometimes darker, that
many have regarded as very rich marl. Thisis what was formerly, and by
forsign writers is still, denominated clay marl. It seldom contains much
lime, and is generally wholly destitute of it even when found in marl beds.
This soapy feeling is a very uncertain indication of lime. Where it is
observed in marl, it is usually owing to something else, chiefly to magnesia or
alumina. A marl is found whiter and harder than the earth to which I refer,
but of the same lamellated structure and a somewhat soapy touch, that is
exceedingly rich in lime,—that at Shell Bluff containing 90 odd per cent.
of the carbonate. It yields readily to the knife, crumbles when exposed to
a severe freeze, and is altogether the most valuable marl we have. Unfor-
tunately, itis not met with in large quantities inour formation. In our marl
beds immense quantities of large shells are generally found. Inexperienced
marlers have been known to spread these on their land. But they are of
little or no value, unless burned or crushed. They were deposited where
they are found before the human race inhabited the earth, and being for
the most part sound yet, will yield Tittle or no lime to the soil in our day.
Even the masses of much smaller, conglomerated shells, though very rich
in lime, are not among the most valuable marls, unless broken up and pulv-
erised to a considerable extent. There is a marl abounding with us, which
to the naked eye seems to be mere sand. that is much more valuable, though
it does not contain two-thirds of the quantity of carbonate of lime: it mixes
at once with the soil and exerts its full influence in a comparatively short
period. The‘most valuable marl, practically speaking, that is found in any
quantity at Shell Bluff—and will be found in your marl-beds, for the forma-
tion is the same—is composed of very fine shells, scarcely discernable, which

5

are loosely cemented together and readily fall apart. It is of different co-
lors; mostly white, sometimes purplish, yellow, or light brown. The most
abundant marl found in our formation is hard and compact, of a grey color,
containing 50 to 60 per cent. of lime, and crumbles on exposure to the
seasons and in handling,

But, as I have said, the value of mar] cannot be estimated by its appear-
ance. Between earth which contains 75 per cent. of carb. of lime, and that
containing 20 per cent., or even none at all, the most experienced are far
oftener than o.herwise unable to distinguish without using the proper tests.
These are so readily to be procured, and in fact the analysis of marl, so far
as to ascertain the quantity of carbonate of lime, is so very simple an oper-
ation, that the marler should leave nothing to conjecture on this important
point. Earth containing any notable proportion of carbonate of lime, will
effervesce if thrown into vinegar or almost any acid. But the best test is
muriatic acid: a single drop of it will produce immediate effervescence
whenever there is carbonate of lime. To discover the precise quantity of
carbonate of lime in any marl, it is only necessary to have this acid, a
pair of common apothecaries’ scales with weights, and a wide mouthed
vial. Dry the marl thoroughly on a shovel, over the fire, and pound it in
a mortar, to a fine powder. Fill the vial about one-third with the muriatic
acid diluted with two parts of water toone of acid, and balance it exactly
in the scales, with weights of any kind. Then add, very slowly, 100 grains
of the powder previously weighed, taking care not to make it effervesce so
rapidly as to throw any of it out of the vial. When the effervescence has
completely ceased, blow gently into the mouth of the vial, with a common
bellows, to expel any of the carbonic acid gas which may have remained in
it in consequence of its being heavier than the atmospheric air. Weights to
the amount of 100 grains must now be put in the opposite scale to balance
the 100 grains of powdered marl put into the vial. It will be found that in
consequence of the escape of carbonic acid in a gaseous form, the scale with
the vial will rise: put weights into it then until the scales are once more
exactly balanced—the number of grains put in the seale with the vial will
of course indicate the weight of the carbonic acid that has escaped. Now
carbonate of lime contains in 100 parts very nearly 56 parts of lime and 44
of carb. acid. If then 44 grains have escaped in your analysis, the speci-
men is pure carbonate of lime. If only 22 grains have escaped, then it
contains but 50 per cent. of carbonate of lime. And so in proportion to any
quantity of carbonic acid which may have been expelled. In practice, it will
be found most convenient to use 50 grains of the powdered marl. A very few
trials will enable the most inexperienced farmer to ascertain in half an hour
with sufficient precision, the value of his marl. That value depending
mainly, as stated, on the quantity of carbonate lime which it contains.

The value of lime for agricultural purposes, is not only established by
the experience of all ages, and so far as we know, of all countries, but must
be obvious, when it is known that chemical analysis has detected it as a con-
stituent of every vegetable that grows on the surface of the earth. It is
also the chief element of the bones of every animal—even of those that feed
on grass only. It is therefore not only beneficial, but indispensable to the
growth of all kind of vegetation. The All-Bountiful Creator has diffused it
over the whole globe, as extensively as almost any known substance. But
like all His gifts, it has been, for wise and good purposes, no doubt, unequally
distributed. That it is placed, in some form and to some extent, within the

6

reach of all plants, is certain, since they all contain it. And a late scientific’
writer on Agricultural Chemistry in our country, has attempted to prove that
all—even the poorest soils, possess an ample supply of it to furnish heavy
crops of vegetation for countless years to come. If this were true, it would
be worse than useless to expend labour in spreading it over our lands; mil-
lions of farmers besides myself have acted very foolishly, and you would do
well tothink no more of marling. But this is plainly not the case. There
are a great many soils in which the chemical tests now known, have failed to
find a trace of it. Such is the fact with regard, I believe, to all the land I
cultivate. Such, I will venture to say, it is » with regard to most, if not all
of the lands in your county; though 1 am aware you have had pretended
analyses made, which exhibited large proportions of lime. The reasoning
of the writer alluded to, is this: All soils are formed by the disintegration
and crumbling of rocks. Most rocks contain lime, especially those which
disintegrate most readily and form soils. He calculates the amount of lime
in the quantum of rock necessary to create a soil of a certain depth, and
thence infers that there is so much lime in the land. There is no doubt
that the rocks from which your soil and mine were formed, contained lime
to the amount estimated. But it is equally certain that these rocks, in their
transition from one state to another, were subjected for an indefinite period to
the action of water. I am speaking particularly of our immediate section
of country. The ocean once undoubtedly covered it as high up as the Falls
of our rivers and the belt of Sand-hills which runs through the middle districts
of South Carolina and Georgia, and held it as permanent domain. During
this period, our mari beds were deposited—possibly also our present surface
of earth. But whether that be so or not, and whether the surface we now
cultivate belongs to the Eocene formation, as these marl deposits are supposed
to do, or to the Post Pliocene, or, as is most probable, to the Diluvial, it is
evident, from the irregular inter-stratification of different kinds of earth,
and the rounded pebbles on and in it, to a considerable depth, which could
have been rounded only by the action of water, that the whole of it, like the
sand and clay now constantly brought down our streams, has been at some
remote period, “drifted” from a higher region, and deposited by water here.
The lime in the rocks being soluble under circumstances which must have
attended the “‘drift,”’? was retained and carried away in the currents. Our
marl beds were probably deposited at a much earlier geological era, arid
have no connection with the soil on our present surface, but were upheaved
or denuded in some of those great convulsions to which our globe has been
every where subjected. That our lands are for the most part destitute of
lime is certain. That it has been taken from them in this way, is more
than probable. The masses of silicified shells to which I have already
alluded, and which are so abundant in your county, prove that the lime
may be entirely carried off by water.

But if there is no lime in the soil, from what source do the growing plants
derive this indispensable constituent may be well asked? It has been often
asked. Nature has not revealed, and science has as yet failed to discover an
answer satisfactory to all. Whether, as is conjectured by some, the unknown
vital action of the plant is sufficiently powerful and comprehensive to create
the requisite modicum—or whether it can, as others suppose, by some gal-
vanic agency,-extract it from sources where its existence has not yet been
detected by chemical re-agents, is yet a mystery. But this much experi-
ence has established and science demonstrated, that where lime cannot be

a

found in fair proportions in a soil, the health and vigour of the plants grow-
ing on it can always be materially improved by a judicious application of it.
And to this conclusion common sense, without experience or science, would
lead every one who was aware that it is invariably an element in all vegeta.
ble matter.

The precise rationale of the action of lime on the soil, and the manner in
which it benefits vegetation, has never been fully and minutely explained.
Nature still holds many of the secrets of her laboratory undisclosed. Many,
and many of the most important details of her wonderful processes of com-
position and decomposition and of the vast play of her chemical affinities,
yet await the persevering investigation and penetrating thought of man. [|
will endeavor to lay before you, succinctly, what is known or rationally
conjectured in regard to the operations and effects of lime, so far as may be
material to the present purpose.

It is applied to land, either directly or mixed, in compost heaps, and car-
ried out in manure. But for the additional labour the latter would always
be the best method. Where it is used in large quantities, it is much cheap.
er to spread it at once upon the land, and apply manure, &c. afterwards, as
circumstances may ‘dictate or permit. It is sometimes put on land in the
state in which it comes from the kiln, that is as quick or caustic lime.
Sometimes it is first slacked in water, when it becomes a hydrate of lime.
Most commonly it is slacked by mere exposure to the atmosphere, when it
assumes the form of carbonate or mild lime, that is lime combined with
carbonic acid, which it extracts from the air in the proportions I have al.
ready stated. It is in this form that it is found most abundantly in nature.
Sulphate and phosphate of lime are also found, but quick lime never. The
lime in shells, marble, limestone, marl, &c. is usually all of it the carbon-
ate. Its action, however, in the long run, is always the same, whether
applied in the mild or caustic state, being dependent on its intrinsic proper-
ties as lime. When caustic, it at first rapidly decomposes whatever of
vegetable fibre or animal matter it comes in contact with. But its caustic
quality is soon exhausted, or rather it soon becomes changed itself by the
action of the substances it meets with, and thus loses its causticity. On
lands containing a great excess of vegetable matter, such as peat and rich
beg, and where rapid decomposition is desirable, quick lime is the best form
of application, if equally cheap, as it saves time, and renders the soil produc-
tive much sooner than the carbonate will do it.

Although lime is found most commonly combined with earbonic acid, the
fact is owing more to the abundance of that acid which exists in the atmos-
phere, in water, and is continually arising from vegetable decay, than be-
cause it has any affinity for carbonic over other acids. On the contrary,
it will yield it up and combine in preference with almost any other. Not
only the strong mineral, but most vegetable acids, even vinegar, as I have
before mentioned, will drive it off. The effervescence which takes place
when carb. of lime is thrown into them, is caused by the carb. acid
escaping in the form of gas. From this great affinity of lime for all acids
results one of its primary and most important effects in soils. Acids are
antiseptic and arrest spontaneous, decay. Lime combines with them
wherever it finds them free from other combinations, and neutralizes their
injurious effect. Hence, on lands that we call sour—and on many that are
really sour without our knowledge of the fact—all land covered with broom
sedge for example—it is of inestimable value. It destroys the sourness,

8

end thereby promotes the decay of whatever matter may have been locked
‘up by acids, which is calculated to nourish useful vegetation. From this
quality of lime, it is denominated an Alkaline Earth—alkali being the
reverse and antagonist of acid. Whenever an alkali and acid meet, they
neutralize one another in certain proportions, and form what is called a salt.
For instance, our common salt is muriatic acid, and the alkali soda. So
carbonate of lime is in fact itself a salt.

These salts, and especially those of which lime is a component part, are
of the highest value in agriculture. Some of them are soluble in water,
and these are the most valuable. It is in fact only when they are thus dis-
solved that they afford any direct nourishment to growing plants which can
imbibe nothing by their roots but watery solutions, and are fed altogether in
this way from the ground. But the salts which are readily soluble in water
are soon exhausted. Every shower dissolves them, and whatever surplus
is left after the plants have absorbed the solution to the extent of their capa-
city, is liable to escape by evaporation, or to be carried by the water into the
earth below the reach of vegetation, or to run off with it into the streams.
Salts then that are not immediately soluble in water, if they can be made
soluble gradually, are in the long run the most useful to the farmer. Of this
class are most, if not all, of the salts formed by lime. Carbonate of lime is
indeed wholly insoluble in pure water, and if lime remained forever in that
state it would be of little value in the soil other than its mechanical influ-
ence on the texture of it. Butifcarbonic acid be added in excess—that is
more of it than 44 parts in 100 which are required to make the carbonate,
this salt becomes soluble. This excess is in point of fact constantly fur-
nished in small quantities by the air, by rain water, and by the decay of
vegetable substances in the ground, and hence, one advantage from keeping
lime near the surface. The lime thus dissolved enters into the plant and
feeds it. In this way, and this way only, is it a direct manure. All its
other influences are indirect, on which account it is most generally regarded
asastimulant rather thana manure. I am speaking, of course, of carb. of
lime as it exists in our marls, and not of the sulphate or phosphate of lime.

Its indirect action however is as important as itis varied. I have already
said it promotes decay by neutralizing acids. But while lime from its
neutralizing power promotes decay, by arresting the influence of acids and
giving efficiency to the legitimate agents which accomplish it, it is a watch-
ful guardian over their action, retarding their wasteful haste, and sometimes
wholly preventing further progress for atime. It expels, for instance, from
decomposing substances, ammonia, which is the most active and rapid con-
ductor of putrifying contagion, driving it into the air to descend in future
showers, or if they are at hand, into other substances less advanced in the
stages of decay,

The ultimate result of the vegetable decomposition thus judiciously for-
warded by lime, is a substance to which various names have been applied by
chemists, such as, ‘‘humus,’’ “geine,”’ “ulmin,’”’ &c., which, so far as agri-
culture is concerned,—their treatment and influence on the growth of vegeta-
tion, are one and the same thing; meaning, substantially, that residuum of
decomposition which is familiarly known to us as “ vegetable mould,” without
a sufficiency of which in our soils, we are all aware that compensating
crops cannot be made, In the progress of decay the most soluble portions
of this mould are exhausted and assume new forms, and what at last remains
apparently fixed in the soil is the undissolved sediment. This is said to be

wholly insoluble in water, but when plowed up and frequently exposed to
the action of the air, it becomes so, sparingly. Yet without aid from some
other source, than the atmosphere, water will not furnish it to plants in sufti-
cient quantities for their vigorous growth. Now the alkalies and alkaline
earths (jime being the most important of this last class) act directly on this
insoluble substance. ‘Their presence—and it is a singular but well known
principle in chemistry, that mere presence is a power called catalytic—induces
it to absorb oxygen from the atmosphere, and to produce what is called
humic acid. With this acid the alkalies immediately combine and form
salts, called humates, which are soluble in water, and afford nourishment to
plants. Jhus when lime is properly applied to land, it brings into fruitful
action the hitherto inert vegetable mould.

But it must be obvious that if no additional vegetable matter is given to
the soil, the effect of lime will be to exhaust it utterly, in a shorter time than
might otherwise be done by cropping. Hence the saying, that liming land
enriches the father but impoverishes the son. It must not be forgotien,
however, that the lime has enriched the father, by giving abundantly to his
crops food that would ctherwise have remained dead in his soil, or been
eliminated by other‘agents, through a series of years, in feeble proportions,
to scant, and therefore profitiess crops: while, if it impoverishes*the son, it
is because a wretched hushandry has taken all from the land, and given
nothing in return. The exhausting effect of lime is mitigated, however, by
another highly important intermediate condition of the process. As the
mould disappears, the proportion of lime to mould of course increases, and
the lime becomes excessive. When this is the case, the humate, which be-
fore was soluble, becomes wholly insoluble in water. ‘The process of de-
composition then ceases for a time. And such is the case very scon,
wherever lime or marl, in very large doses, is put on jand possessing but
little vegetable matter. It is called “marl burnt,” among the marlers—
many instances of which I can point out on my plantation. In course of cul-
tivation, however, the lime being constantly exposed to the atmosphere,
absorbs carbonic acid, which combining with a portion of it, converts it into
carbonate of lime again, and thus freeing the humate, or a part of it, of the
excess of lime, renders it soluble once more. But this is a very slow process,
and unless there are immense quantities of vegetable mould which have
been thus locked up by an extraordinary and injudicious application of lime,
and probably even then, the proper plan is to remedy the evil at once, by a
heavy coating of vegetable matter brought fresh from the woods. When
this cannot be effected, we should give the land a long and absolute
rest, allowing every particle of vegetation it produces to rot upon it, and if
it can be conveniently done to plow it in. ‘The best of all methods, however,
to restore the land, and not always the most expensive, would be to add a
sufficiency of compost manure. Besides the amount of decayed vegetation
which such manure would supply, the alkalies potash and soda are always
generated in compost heaps. ‘These act directly on the insoluble humate of
lime, decompose it by their greater affinity for the humic acid, and form new
salts which are quite soluble.

Instead of objecting to this action of lime in locking up the food of plants,
and its constant tendency to do so when that food is not made abundant by
good husbandry, we should rather regard it as one of its most valuable pro-
perties. . The vegetable mould was dead in the soil. It could not be carried
away, but it was of little value as it stood. ‘The lime by its presence per-

10

suades it to decompose in sufficient quantities to nourish a luxurious growth
of plants. So soon as the mould begins to become scarce, the lime confines
it in its embraces and preserves it from the wasteful influence of heat and
moisture. Yet to the industrious farmer whose constant furrows give ac-
cess to the atmosphere it yields up what a prudent economy would dictate
under existing circumstances, to promote the growth of vegetation. If that
vegetation is permitted to remain and decompose upon the land, ‘“ vegetable
mould,” in time, becomes abundant again, and the lime prepares it to fur-
nish ample food for heavy crops once more. If all the produce is taken off,
the lime, more provident than the farmer, and more generous too, still pre-
serves what remains in the soil, for the exclusive use of the crop, and doles
it out until all is gone.

The influence of lime upon the mineral substances of the earth is searce-
ly less powerful and important to the farmer, than on the vegetable. ‘The
chief mineral constituents of the soil are, as you know, sand and clay.—
They are usually resolved by agricultural chemists into what they call
silica and alumina, which are silicon and aluminum, their ultimate princi-
ples, with a little oxygen absorbed from the atmosphere. Of these two
silica is much the most abundant as well perhaps as most valuable. After
what we ¢all clay has been deprived of its sand by washing, in which state
it is usually denominated pure or agricultural clay, it still holds in chemical
combination from 59 to 60 per cent. of silica. The purest pipe clay we find,
is half silica; and the stiffest red lands of your county probably contain at least
70 per cent. of it, and not more than 15 per cent. of alumina. Lime and
alumina have a strong affinity, and from their combination and subsequent
decomposition results the important and well established fact, that the stiff. >
est clay lands are rendered light and mellow by liming. ‘The rationale of
this process has never been satisfactorily explained. ‘The effect is usually
referred to the mere mechanical operation of the lime. But this cannot be
so, since an hundred, or at most a few hundreds of bushels per acre of one
earth, could not materially alter the texture of another, to any depth. It is
probable that the crumbling of the clay, after liming, will be found to be owing
to the condensation by severe cold of the carbonic acid supplied by the lime,
and its extraordinary power of expansion under the influence of returning
heat, since this disinteration of stiff lands has never been observed until a
winter has elapsed after the application of lime or marl. Alumina will not
combine with carbonic acid; and it may be that clay lands are opened
partly by the incessant changes occasioned by the affinity of lime for both.
Being insoluble in water, alumina furnishes of itself little or no aliment to
the growing plant, though it has other indirect influences fully in proportio
to its conspicuous position as a constituent of soils. .

Silica, on the contrary, enters largely into the formation of the plant. It
has, as I have mentioned, acid properties, and combines with the alkalies
and alkaline earths and metals, forming salts of the greatest value in numer-
ous points of view, which are called silicates, It is the silicate of potash,
sometimes replaced by that of soda, and to some extent by that of lime, which
forms the outer coating of straw, stems, stalks, &c., giving both strength
and protection to the plant. These silicates are insoluble in water, so
much so that they constitute the chief ingredient of rocks. But that uni-
versal and inexhaustible agent, the carbonic acid of the atmosphere, acting
on the alkaline bases of the silicates, decomposes them: hence the gradual
breaking down of rocks under atmospheric infiuence. The presence of

11

lime is also known to influence the decomposition of the silicates of potash and
soda, and at the moment of decomposition, both the silica and alkali are solu-
ble. Thus, lime aids materially in supplying these essential elements to
plants. Whether it does so by its alkaline properties, or by concentrating
carbonic acid, or merely by its catalytic power, has not been settled. The
silicate of lime itself, when rendered soluble by the decomposing influence
of carbonic acid, sometimes, as I have stated, becomes, in their absence, a
substitute for the silicates of potash and soda. It is this combination also,
that renders light sandy lands more consistent, which 1s one of the most
important effects of lime on such lands—particularly on the light uplands
so extensively planted on this side of the Savannah, ‘and in your county.
The fact is unquestionable. It is usually referred, as is the opening
of stifflands, to the mechanical influence of the lime, but the cause assigned
here, as in that case, is not adequate to the effect.

The red and brown lands in your county are colored, as they are every
where else, by iron. You have no doubt observed that, after continued
cultivation, some of the best of them cease to become productive without
much apparent loss of vegetable mould, and are not rapidly restored either
by rest or manure. ‘Among other causes, this is owing, to a considerable
extent, to the excessive oxidation of the iron in consequence of its exposure,
from plowing, to the atmosphere, whence it extracts oxygen, a proccss you
see constantly exemplified by the rusting of old iron. It becomes what is
called a peroxide of iron, which is very injurious to vegetation. Lime neu-
tralizes all acids, and if put upon these lands in proper quantities, it will
neutralize a portion of the acid in the iron, and convert the peroxide into a
protoxide of iron, which, if not actually beneficial, is at least harmless to
plants. You have too, in some of your soils, the sulphuret of iron, so often
taken for gold ore. This, on exposure to air, absorbs oxygen, which produ-
ces sulphuric acid, and then forms the sulphate of iron or copperas, which is
poisonous to plants. If lime is put on the land it will arrest the accession of
the sulphuric acid, thus formed, to the iron, and prevent the formation of
copperas. But what is more, combining with the sulphuric acid itself, it forms
sulphate of lime, commonly called plaster of paris, one of the most highly
prized of all mineral manures, and an element in all, or nearly all plants.
Lime has also the power of forming plaster in the same way when it comes
in contact with sulphate of silicon, which is supposed to exist in all soils.
It combines also with sulphuric acid, arising from vegetable decomposition
or any other source, and produces this valuable salt. t.

The sulphate of lime, called also gypsum, as well as plaster of paris, must
exist to some extent in all soils, as it is found in almost all plants. But, like ~
the carbonate of lime, it is seldom to be detected by chemical tests. It may also
be eliminated from unknown combinations by the vital action of the growing
plant. But in the way I have mentioned, it will undoubtedly be formed in
greater abundance in all soils, by the application of lime. Sulphuric acid itself
is often used as a manure, but experience has fully established the fact, that it
is of little value except on calcareous soils ; and what is more remarkable, that
sulphate of lime will also act with far greater effect on limed lands. I tried
some of it myselfthe past year on marled land. T rolled the cotton seed init,
previously to planting them, and thus applied it at the rate of only one peck
of the plaster per acre. I am satisfied that the product, on the few acres to
which it was applied, was one third greater than on similar adjoining land,
marled also, but not plastered. I anticipate, therefore, the greatest benefit

12

from the use of plaster after marl. I should remark, however, that it has not
been found invariably beneficial even on limed lands. In England, and on
our coast, south of Long Island, little advantage has been derived from it.
‘Two probable causes have been assigned for this: the influence of sea air,
which has not been satisfactorily explained, and the probability that the lands
in the regions mentioned have derived a sufficiency of gypsum already from
the sulphuret of iron, or other sources, Very little is required for plants :
one peck per acre applied to the moistened seed will probably have as much
effect, for one year at least, as any other quantity. In the last dry season it
had, cn my land, double the eflect of a bushel sown broadcast. Five to ten
bushels are sometimes applied.

Phosphate of Lime is even more esteemed for a manure than the
Sulphate. It is sometimes called the “ Harth of Bones,” as bones contain
over 50 per cent. of this salt. Being less abundant than sulphate of lime,
it is much more costly. Bones are transported across the Atlantic to Eng-
land, to be used as manure. Several hundred vessels are now engaged
solely in transporting bones from various parts of the world to England.
This phosphate is also an essential constituent of plants, though rarely to
be detected in soils. But phosphoric acid, like sulphuric, arises from vege-
table decomposition, from phosphuret of silicon, and perhaps other sources.
If lime be present in the soil to fix it, not only is the vital action of the plant
relieved from producing it, but much is probably saved that would other-
wise be lost. The ash of cotton seed contains considerably more of this
acid than bones do, and hence the immense value of this seed as a manure.
But its effects are proverbially transient. With lime in the soil sufficiently
abundant to fix the phosphoric acid, cotton seed would be a manure almost
as permanent as bones. But to detail all the operations of lime in the
soil, in assisting to prepare food for plants out of the vegetable and min-
eral substances—which compose it—would require me to write a much
longer letter than you would read with patience. I have touched on the
most prominent only. The general consequences, however, which follow,
and which are regarded as arising peculiarly from its applications to land,
require to be glanced at. |

By opening stiff land, it renders it more permeable to the air, and more
subject to atmosperic influence, while its surplus water more readily escapes.
Quick-lime, when saturated, holds mere water than common clay, such as
yours, but yields it more readily to heat, and is therefore of great use in
drying damp lands and rendering them warmer. But it does not give up its
water so promptly as sand, and therefore renders that more retentive of
moisture. In fact, Marl containing 50 per cent. of carbonate of lime,
and the residue chiefly fine sand, will absorb more water than the com-
mon clay of your lands, and retain it as long. During the extreme
drought last year, at one time, the plow turned up dry dirt in a field of
mine marled that year at 100-bushels per acre, and not yet sufficieutly
mixed in the soil, while several days later, without intervening rain in
a soil equally sandy and having less vegetable matter, but marled four
years ago with 200 bushels per acre, earth quite moist was turned up at
the same depth. You will readily perceive and appreciate the value of
marl in this respect. :

By rapidly neutralizing the noxious, and vivifying the good properties of
the subsoil brought up in breaking land, lime enables the farmer to deepen
his soil more speedily and without risk. Mr. Ruffin’s experience confirm-

13

ing the theory, is decisive on this point; mine, so far as it goes, is to the
same effect. Lime undoubtedly hastens the maturity of crops. Writers
abroad state that it advances them a fortnight. Before seeing these state-
ments, my observation of my own crops had led me to the same conclusion.
Two weeks gained to the cotton plant is equivalent to a degree of latitude—
a very material gain to us.

It is also stated on good authority, that lime in land improves the
quality of every cultivated crop—and that it has the effect of increasing
the fruit in proportion to the weed. It is well known, that while the
straw, stalks, é&c. of plants, contain more of the carbonates, the seeds
contain more of the phosphates. If the application of carbonate of lime
increases the fruit more than it does the stalk, its indirect influence in
produeing phosphates is greater and more important than has been generally
supposed, and its value is enhanced in a corresponding degree. It is said
also to extirpate many noxious weeds. However this may be, I can testify
that it gives great luxuriance to the growth of all the grasses with which our
crops are infested. This, to the mere corn and cotton planter, may be no
recommendation ofit. I will state, however, that in a field planted in cotton
in 1844, and rested last year, which usually produces a heavy crop of hog-
weed, when turned out, there came up, although it had not been plowed at
all, an uncommonly fine growth of crow-foot; which I can only account
for from its having been marled. The part longest marled had the best crow-
foot.

Lime is thought in England to prevent smut in wheat—to destroy many
injurious insects—to preserve sheep pastured on land after its use from rot
and foot-rot—and it is every where regarded as improving the healthfulness
of drained lands. In short, it isnow generally agreed, not only by scientific
men, but by the best and most experienced farmers in every part of the world
where it has been properly tested, that ‘ Lime is the basis of all good hus-
-bandry,”’—in which opinion I fully and cordially concur.

In endeavouring to furnish you with something like a theory of the action
of Lime, I have stated some—perhaps many things—which are questioned
by men of great scientific attainment. Agricultural Chemistry—indeed
the whole science of chemistry—may be said to be yet in infancy. If it
is difficult to penetrate the arcana of passive nature, it is far more so to in-
vestigate those active operations which are conducted in the air and under
the ground, in the formation of plants, complicated as they are in addition
by the yet unknown vital agency of the plant itself. Although, on the
whole, the art of agriculture has been vastly advanced by the discoveries
and experiments of chemists, and he who shuts his eyes to the light they are
constantly shedding for the benefit of farmers, is now, and will soon be much
farther, behind his age ; still it is well known that great absurdities have
been put forward, and with the utmost confidence, by the most emi-
nent characters in modern science. In speaking, then, of the peculiar
action of any of the elements out of which plants are formed, and its
agency in the mysterious operations consummated in the production
of a full-grown, matured and fruit-bearing plant, it is not only becoming,
but necessary that every one, most especially a mere farmer like myself,
should express opinions with great diffidence and cau‘ion, and hesitate before
drawing even from established facts, inferences of important and extensive
bearing. In view of this, I ought not to omit to state to you, that within a
few years past, a sweeping theory has been suggested by one of the first

14

chemists and most popular writers of the age, that has found some able
supporters, and which if true apparently upsets every thing that has been said
of the effect of lime in furnishing food to growing plants out of decayed vege-
table matter. Dr. Liebig asserts that the decayed vegetable matter of the
soil called humus, or mould, affords no direct nourishment whatever to
plants. That they derive all their organic constituents from the atmosphere,
and only their inorganic from the earth. The organic constituents of plants
are those which are dissipated when they are burnt, and in most vegetables
amount to from 97 to 99 parts in 100. ‘The inorganic constituents compose
the ashes which are left by fire, amounting usually from 1 to 8 parts in 100, in
some rare cases toas much as 12 per cent. The only nourishment which,
according to this theory, the soil atfords to plants, being thus limited to from
1 to 3 parts in 100, the utmost direct influence of good or bad soils, of manure
of all kinds—of lime, alumina, silica, and all mineral elements, can reach
no further than to the modification of an hundredth or at most a thirty-third
part of the crops we cultivate. It follows that the world has all this time
laboured under a most important error in estimating at such vastly different
values, what we call rich and poor lands. That the effects of manure are ina
great measure fanciful, or at least that from 1 to 3 lbs. of ashes are equivalent
to 100 lbs. of vegetable matter, as an application to the soil, and that it is use-
less labour to put on manure in any other form. Knowing as we do that a
single drop of prussic acid will almost instantly extinguish life, it would not
be fair to deny very great influence to even the smallest proportion of inor-
ganic matter in the production of plants. And since Liebig concedes that
until the leaves are formed, the plant derives its carbonic acid from an arti-
ficial atmosphere generated by the contact of humus in the soil with the air,
it would not be safe to denounce this theory in the present state of science, as
absurd. It is admitted too on all sides that plants do assimilate carbon from the
atmosphere, and it seems established that ammonia descends in rain water.
However true this may be, and though Liebig’s theory was established as
perfectly so in all its parts, I should think it most prudent to hold on still to
what experience and rational deduction have taught us of the influence of
vegetable mould on crops, in the hope that further discoveries might harmo-
nize old facts and new truths, especially as none of us would set about improv-
ing the atmosphere, or desire to add more carbonic acid or nitrogen to it, since
any material increase of these elements would render it fatal to animal life.
Indeed, no scientific discoveries or force of logic can ever, I am convin-
ced, for an instant shake your confidence or that of any practical farmer,
in vegetable mould and compost manure; or lead you to doubt that the
amount of your crop, if properly tilled under fair seasons, depended in all
other respects wholly and solely on the quality of your land. Whether the .
soil furnishes 1 part or 99 parts in a hundred—you have too often seen plants
on the same acre subject to the same identical atmospheric influences
throughout, varying from good to worthless, according to the soil, to question
the inportant fact that by improving your land you improve your crop in
the same ratio precisely, and that by exhausting it you equally deteriorate
the crop.

In fact, depth of soil, by which we mean depth of decayed vegetable
mould, depth of decayed vegetable mould mixed with sand, clay, &c.,
has been with you, as with all the world, heretofore, a criterion, and a never
failing one, of the value of land, and so it will forever continue to be, I
venture toassert. If then, as I believe, and you will probably agree, plants

15

derive their most important constituents of all kinds from the soil and from
vegetable mould, the value of lime in the soil is by no means limited to its
action on the mineral or inorganic constituents of it, but extends to the pro-
duction also of those organic elements which preponderate so immensely in
all vegetation.

_ But your inquiry of me was in reference to Marl. I must therefore
remind you again, that all which has been said of lime is true of marl. Ifit
is slower than lime in its early operations, that is more than compensated
by many advantages which it possesses. This is becoming so well under-
stood, that wherever the same quantity of lime can be placed on land as
cheaply in the form of marl, it is rapidly superseding the use of it in all
other forms. Marl contains besides carbonate of lime other valuable con-
stituents. Its silex and alumina though fine in quality are not of much con-
sequence, since they are never thus applied in sufficient quantities to effect
the soil materially. But some marls—those in Virginia, for instance—con-
tain sometimes sulphate of lime and the valuable green sand of which I
have spoken. As the sulphate of lime exists there in Eocene Marl
it may be discovered in our formation. I have seen green sand in
specimens from several localities in this State. A deposit of green sand,
such as is found and used to an immense extent in New Jersey, would
be more valuable in your county than the richest gold mine in the
world. There is none of it at Shell Bluff. I have already spoken of
phosphate of lime. In marl from Ashley river, in this State, which
belongs to the same formation as our marls, 5 per cent. of this phosphate
has been discovered. From some crude experiments of my own, I
am inclined to believe it exists in some of the marls at Shell Bluff, and
probably in yours——to what extent I would not undertake to say. But
5 per cent. of it would give you the equivalent of 9 bushels of ground
bones in every hundred bushels of marl, which alone would be worth
more than the whole cost of applying that quantity of marl, though
the expense of it might be five dollars. We cannot, however, expect to
find it in such quantity in all the marls we use. Those will probably be richest
in it in which are found remains of bones and teeth. In the shell marls on
the Rhine, recent analysis has detected an important proportion of azote,
derived it is supposed from animal matter. This is the most powerful, as
you know, of all manures. There is every reason to believe that a
scrutiny equally rigid would disclose a valuable proportion of it in our shell
marls here.

The duration of marl in the soil, is undoubtedly greater than that of lime.
The question of the duration of calcareous earth applied to lands, is one of
great importance itself, and about which you will no doubt desire to be satis.
fied before attempting to use it. I have mentioned already, that the ancients
regarded marl as producing its effects from 10 to 80 years. Lord Kames
states an instance of their being observable for 120 years, and Mr. Ruffin
another of 60 years. Few or no records of such experiments have been
handed down from generation to generation. In those countries where lime
and marl have been used most extensively and for the longest period, it is
impossible to say how the land produced before they were applied at all, in
comparison with its production now. Of late years, more accurate accounts
have been kept. The peculiar effects first observed to follow the application
of lime, have been thought to disappear or materially diminish at various pe-
riods, reaching from 4 to 40 years, according to the amount applied and other

16

circumstances. It is supposed by writers and farmers abroad, that about 34
bushels of it are consumed per annum by the crop, and that in general the
influence of any quantity will cease in from 12 to 20 years. But these
conclusions are not to be relied on. It is certain that no crop will take off
so large an amount as 34 bushels, and the loss from other causes is altogether
indefinite. While though at the end of 20 years, the same precise effects
as at first may no longer be observable, it by no means follows that this may
not be owing to the want of proper applications of other manures that would
excite the lime again to its original action. Mr Ruffin thinks that marl once
placed on land, will endure as long as the clay and sand in it. Though we
might not indulge fully in this belief, 1 am of opinion that it will last for a
period which may be called indefinite, from its remoteness—particularly when
crops are grown such as we cultivate. Irish potatoes consume more lime
than any other crop, perhaps; nine tons, which are sometimes grown upon
an acre, though not with us, abstract about 266 lbs. or say 34 bushels—but
260 lbs. are contained in the tops, which we never take from the land. A
thousand bushels of turnips, tops and all, consume about 2 bushels of lime.
Wheat, the cultivation of which is extending among us, requires for a crop of
25 bushels, straw and all, about 9 lbs. ora half peck. Cotton and corn do
not require more. Seed cotton sufficient to make a bale of 400 lbs—that is
1400 lbs. in the seed will consume about 3 lbs., and most of that in the seed
which is invariably restored to the land. If we treble this amount for the
stalks and leaves, which however usually rot on the groond, the exhaustion
of lime by our heaviest cotton crops will not exceed half a peck when every
thing is taken off. Thirty-fewe bushels of'corn will consume only about 13 Ibs.
of lime; if we add six times this amount for the cob, shuck, blades and stalk,
it will not require more than cotton or wheat. I am not aware that our cot-
ton stalks, or our corn-cobs, shucks, stalks or blades, have ever been analyz-
ed; but I have, I think, fully allowed for the lime they may contain. And
at these rates of exhaustion, 30 bushels of lime, which is about the quantity
contained in 100 bushels of marl that has 60 per cent. of the carbonate, will
supply the wants of our usual crops, when much larger than we now aver-
age, for 240 years, if the land was cultivated so long without rest or restor-
ing any thing to it. The consumption of the crop then is next to nothing.
The loss arising from other causes is undoubtedly greater. Quick-lime dis-
solves in 750 parts of water. A fall of 44 inches of rain, which is less than
the annual average quantity that falls here, would afford water sufficient to
dissolve 170 bushels per acre. Quicklime when spread on land, however,
becomes a carbonate, and nearly insoluble, too soon to lose to this
extent. Still,a considerable amount might be lost in this way, by a heavy
rain immediately after liming. Lime after being burnt, falls into a powder.
Its minute particles are forced by showers, aided by deep plowing into the sub-
soil, and much may be thus carried off. When these things are considered,
it is obvious that all tie lime in land may in time be exhausted, as it has been
from our “drifted” soils. But the chances of its duration are greatly increased
by being applied in the form of mar!. Being a carbonate, it is soluble by the
carbonic acid in rain water only in small quantities, and ages must elapse
before it could dissolve and carry offany great amount; and not having been
reduced to a fine powder, its particles are too large to be readily driven down
into the subsoil, below the reach of the plow. Without, then, assigning any
precise limit for the duration of marl, I think it may be safely concluded,
that the effects of a sufficient application, under proper culture, will last for a

17

longer period than we can conceive ourselves to have any direct interest in
the land to which we may apply it. dh

With regard to what is a sufficient application, there is a great diversity
of opinion, and consequently of practice. Viewing it chiefly as a direct
manure, in many parts of Europe, lime is applied at the rate of 8 to 10 bush.
els per acre annually—in others, at 10 to 12 bushels every third year ; and
again, in other parts, at 40 to 50 bushels every twelve years. But as its
indirect effects are as important, and far more numerous than its direct, and
it is therefore an invaluable elementary constituent of soils, the true rule for
its application undoubtedly is to furnish the soil at once, if possible, with as
much as its constitution will bear, and to repeat the dose as frequently as the
improvement of that constitution will permit, since the more lime, every thing
else being in due proportion, the larger the crops. Acting on this principle,
many farmers in Europe put on 3 to 4U0 bushels of lime at once, and some-
times 1000. Such liming is probably excessive there, and in our climate
would be utterly destructive. Marl, however, containing from 50 to 70 per
cent. of carb. of lime, may be safely used in four times the quantity we can
use quick lime. The usual dose of marl of that quality in Virginia, varies
from 2 to 300 bushels. But more can be applied even in Virginia than here.
The hotter the climate, the more caution is necessary in the first dose at
least. Though this is greatly dependent on the condition of the land to be
marled. Inthe hot and dry climate of Egypt, the fruitful Delta of the Nile
contains 25 per cent. of carb. of lime, which is equivalent in one foot depth of
soil, to some 20,000 bushels per acre of marl containing 50 per cent.; but that
soil is much deeper, and its vegetable mould inexhaustible. Depth of soil,
and the amount of vegetable matter in it, must chiefly regulate the quantity
of marl. M. Puvis has given an interesting table in reference to this. He
thinks that we may give to a soil three inches deep, 40 bushels of marl, con-
taining 60 per ct. of carb. of lime, or 50 bushels containing 50 per ct.; and
to a soil six inches deep, 80 bushels at 60 perct., or 100 at 50 perct. He
does not refer to the vegetable matter, or other circumstances of the soil. I
presume that the depths ofthe soils you cultivate range between the extremes
stated, or at least that you seldom plow, and would not, therefore, mix the
marl deeper than six inches. I think the amounts he specifies are very safe.
As some of my Jands are similar to yours, and our climates the same, I will
give you my experience on this point. I began to marl by putting 200 bushels
per acre, that averaged about 60 per ct. carb. of lime. On old mulatto land,
with a soil about six inches deep, and containing about 4 per ct. of vegetable
matter, I have not yet, after four years, perceived any injury from it. On
lighter land, containing less vegetable matter, and a soil four to five inches
deep, I discovered marl burns the second year. Previously to this discovery,
however, I had taken the alarm, and reduced the quantity to 150 bushels, on
land similar to the last mentioned. On all the thin spots I perceived the
“marl burn” from this amount. I then further reduced the marl to 100
bushels per acre, from which I have as yet perceived no injury. Being now
about to finish the marling of all my open land, it is my intention to go over
it again, and to add 50 bushels per acre at a time, until I have given to all
200 bushels. I shall by no means, however, venture to do this until,
by resting and manuring, I have also furnished to it additional vegetable
matter, |

I think I may safely recommend you to apply 100 bushels per acre, of the
richest marl you have, to any land set now gives you remunerating crops,

18

and 200 bushels, or more, to your best lands. they are low and sour they
will bear still more. [am now putting 250 to 300 bushels on some swamps
I have drained, which have several feet of vegetable mould. I should
not be afraid to put 1000 bushels per acre on such land—though here I think
quick lime would-be the best application, as it would hasten decomposition. .

Itis always most convenient to apply mar! to resting lands, and it is also a
great advantage to secure, by this means, a new coat of decaying vegetation
to start with. So new grounds should be marled the first year: if marled
before clearing it would be better still, Very old and exhausted land should
be rested two years previously to marling ; and in all cases, thin knolls should,
if possible, be manured when mariled. But a little experience will furnish
you the best guides in this regard—you will soon discover all the dangers,
and learn to apply all the remedies.

Experience will also teach you in a very short time, the best and most
convenient methods of digging, carting, and spreading marl. There are
some difficulties connected with digging from marl pits, which, with the
means of overcoming them, are stated in Mr. Ruffin’s work. They arise
chiefly from water, which must be drained off, or pumped out, according to
circumstances. I have no experience on this point. My marl is cut from the
face of the cliff at Shell Bluff. It is estimated that if a strata of marl is 12 feet
thick, 12 feet of covering may be removed to procure it, without hazarding
too much. But should you find marl, you need not apprehend much danger
of working through it. The great formation of which it isa part, is of un-
known depth. Over 100 feet of it is exposed at Shell Bluff; it has been
penetrated more than 300 feet in Charleston.

In hauling out marl, the most economical method is to use carts with two
mules or horses. In a cart properly made, they will haul 18 bushels at a
load as easily as one mule will haul 6. The carts should be made with three
shafts, so as to divide the weight of the load equally between the mules, and
the tread of the wheels should be 4 inches—axle-trees of iron. In putting
on 100 bushels to the acre, the land should be divided by furrows into squares
28 yards each way. ‘This will give 6to the acre. A load of 18 bushels to
each square will rather exceed 100 bushels per acre, but some will always
be lost. The full effect of marl cannot be felt until it is thoroughly mixed
with the soil. Hence the first year, little is to be expected from it, and it sel-
dom reaches its maximum until the fourth crop—not always then. Its effects
may be hastened, and what is also important, rendered equal, by spreading it
with regularity over the land. It is best, therefore, to sow it broad-cast with
the hand. Each labourer should take his square and spread the pile, using a
tray or board to assist him. A hand will spread 9 piles, of 18 bushels each,
in a day.

The distance to which marl may be carted depends altogether upon cir.
cumstances—one of which is the quality of the marl—another, that of the
land—others, the facilities for digging, state of the roads, &c. Along the
coast of Scotland, it is transported by sea from 80 to 100 miles.. I have been
very recently informed, that at a single marl bank on James river, in Virginia,
10 rigged lighters are now engaged in delivering marl to a distance
of from 8 to 20 miles up and down the river, receiving 3 cents per bushel
for it, though it is much inferior to ours in quality. The marl I use, averages
about 60 per-cent. of carbonate of lime. I cut the whole of it down at
Shell Bluff, and boat it 12 miles up the Savannah river, re-land and cart it.
Ihave marled about 700 acres within a mile of my danding here—but I

19

have hauled some mar! 4 miles, and have spread it on about 500 acres, the
nearest part of which is over three miles from the river. This is of course
very expensive; but I think it profitable, notwithstanding. If I could lay
down any rule to regulate the cost of marling, it would be this: ‘That where
land is deficient in lime, it would be a safe operation to expend an amount
equal to the present value ofit, ifso much should be necessary to mar! it suffi-
ciently. This rule I suggest upon the principle, that it would be profitable to
pay twice for land, if you could thereby doubie its production without materi-
ally increasing the cost of cultivation. .

You will naturally inquire, whether any one might reasonably calculate
on doubling the production of his land by marling. 1 believe he may,
if the marl is judiciously applied and the proper system of after-cultivation
adopted. I have seen but few statements of the actual results of marling in
Europe. It is said in general terms to produce a great increase, though oc-
casionally it is mentioned that the crops were doubled. So perfectly estab.
lished is the use of lime and marl there, that every one who can procure
them, uses them as a matter of course. It is not considered an experiment,
and tables of results are not therefore given—at least, ] have seen none. A
few years ago, Mr. Ruffin addressed interrogatories touching the eflect of
marl as exhibited in the crops, to a number of the most respectable farmers
of Virginia, who had used it, and received answers from twenty-two, many
of whom had marled extensively and for a number of years past. These
answers were published in the Farmer’s Register and in Mr. Ruffin’s Report
of his Agricultural Survey of South Carolina. ‘Their marl was of various
qualities, applied in various amounts per acre, and on different kinds of land,
which had been subjected generally to very severe cropping before. No
one of these estimated the increase of his crops from marling at less than
double, and some of them rated it as high as 400 percent. I have no doubt,
that under favourable circumstances and good management, the last men-
tioned increase, enormous as it is, may be often realized. The prospect, how-
ever, of doubling the crop with reasonable certainty, is promise enough one
would think, to set every one to marling who can do it within the cost I have
mentioned. I have not myself, yet doubled my own crop by the use of marl,
nor might the practical results of it, which I ought to state, be so striking toa
careless observer as he might expect, after all I have said on the subject.
They satisfy me, however; and | feel perfectly certain that in a short time,
the crops on all the land I plant, will be at least doubled, from the effects of -
marl alone, and much more than doubled, in consequence of other additional
applications | am making. [commenced marling in November, 1841. I
marled only 175 acres for the crop of 1842, the results of which I reported
to our State Agricultural Society, as I did those of 1843, on the same land,
They were published, and some of you may have seen them—lI will therefore
only repeat the tabular statement of those years, and add to it that of the
past year. In 1844, these lands rested. ‘The experiment marked No. 1, was
made on mulatto land lying on the river bluff, which in appearance, and
perhaps in most other respects, is much the same as the best upland cotton
soils in your county which have been as long in cultivation. Experiment
No. 2, was on light, sandy soil,—the sand is very fine, but altogether, the
soil is as inferior as any probably that you plant in cotton. I could scarcely
have selected lands less calculated to give the marl a fair chance—both having
been cleared more than a century ago—badly scourged, and ofcourse greatly
exausted of vegetable matter.

%

20

Expertmment No.1. Muvrattro Lanp.

1842. ved Cotton. LoS eo halen ig More Se Pree
Acre not marled. 1111 lbs, .
Do. maried 100 bush. 846 * 265 lbs. 30.
Do... dos: 20005..4,,0h008. % 108 “6 10.7
Do. ~dos:: 300 #21818 |“ ; 207 lbs. Lit

1843. fs
Acre not marled. 493 lbs.
Do. marled 100 bush. 654 * 161 lbs. 32.6
Do. do 200 * Fog & 266 * 53.9
Do, 4.d0....c00.. . B41 348 §§ 70.

1844.

RESTED.

1846.
Acre not maried. 324 Ibs.
Do. marled 100 bush. 481 “« 157 lbs, 48 4
joo? “dey 260° FS 4 : 260 * 80.2
Doe, "do. "300°." 642 318 98,

Experiment No. 2. Sanpy Lanp.
* kat

1842. Fork, Les gain i Se spi ae Antigo >: iy oe
Acre not marled. 17 bush, .
Do, marled 100 bush. 21 * 4 bush. 23.5
Daiewerdoy:-200..4:° 21 A ae 23.5
Do. do. 300. 184 & 14 #4 8.8

1843. ‘

Seed. Cotton,

Acre not marled. 361 Ibs.
Do. marled 100 bush, 451 * 90 lbs, 24.9
Po, .do 200 * “384 23 % 6.3
Do, do. 300 “ 173 * 188 » 108.6

1844.

RESTED.

1815.
Acre not marled. 230 lbs.
Do. marled 100 bush. 317 « 88 lbs. 37.7
Do. do. 200 * 301 * Wi 30.8
Do. do 3800 * 159 *% 71 cs 44.6

The first thing that will strike you on looking at this table, will be, that
the crops have regularly and excessively diminished, from the time the land
was marled. It might be concluded that] had ruined my land by mazling.
Such I will candidly own would have been my own conclusion, if fortunately
I had not kept these unmarled acres to test the success of my operations.
Disastrous as have been the three last crop seasons in this section of coun-
try, I would not have believed it possible that there could have been such a
falling off from seasons alone, and I should have abandoned marl, in spite of
the experience of the rest of the world, as injurious, at least to my soil. But
great as has been the decrease of production on all the acres, it has been far
greatest on the unmaried ones. ‘bat ofthe others, has comparatively stead-
ily increased, except the 200 and 300 bushel acres in No. 2, both too heavily
marled, but both recovering again under the rest of 1844. In No. 1, the acre

21

with 100 bushels has increased from 30 per cent. below, to 48.4 per cent. above
the unmarled one—making an actual comparative increase of 78.4 per cent.
The acre with 200 bushels, has inthe same way increased 90.9 per cent.
Both these acres are decidedly inferior to the other two in No. 1, and have,
I do not doubt, produced this year double what they would have done without
marl. ‘The other two acres in No. 1, area pretty fair test of the influence
of marl, being as nearly equal in quality as could have been selected. ‘The
sandy land, in time and with proper management, will, I am certain, exhibit
results fully as favourable as the mulatto land. It was too far exhausted when
marled. [did not reserve test acres on any other fields, but I feel sure that
they have derived equal advantage from the marl, in proof of which I could
state many facts to one present on the spot, which it would be tedious to men-
tion and explain fully inthis letter. I will only state one: The unmarled acre
in No. 1, is one of the best acresI plant. In 1842, it yielded 1111 lbs. The
average of my whole crop that year, was 666 lbs. per acre. ‘The last year,
the same acre, after a rest, produced 324 lbs. The average of my crop was
391 lbs. peracre. Thus, the yield of the unmarled acre, was in one instance
66.8 per cent. above, and in the other, 20.6 per cent. below the general aver-
age—making a difference of 87.4 per cent. in favour of the marled lands.
Let me add that in 1842 the unmarled acre in No. 2 produced 8.8 per cent. less
than the average of the crop. In 1843 it fell to 37.6 per cent., and in 1845
to 70 per cent. below the general average. If these facts may be assumed
as data, on which to base a calculation, had the last year been as favourable
in all respects as 1842, the average of my cotton crop must have been over
1200 lbs. of seed cotton per acre, and of my corn crop over 28 bushels per
acre. This however is only a paper calculation, and 1842 was a fine crop
year. ‘lime will reveal the truth.

I cannot give you a better evidence ofthe firmness of my faith in the virtue
of marl, than to state, that notwithstanding the discouragements of the last
three extraordinary seasons, [ have, at great expense, brought up from Shell
Bluff, within four years, over 300,000 bushels, carted it out, and spread it
over about 2300 acres of land; and am at this moment as actively engaged
at it asever. NordoI look forward to a period whenI expect to cease using
it to a considerable extent every year, either on fresh lands, or in increasing
the dose on those already marled. It would be leading you into error, how-
ever, to leave you to suppose that I rely solely on the marl to improve my
lands. Rest, in connection with it, is indispensable, and manure becomes far
more beneficial. I have, accordingly, by opening more land, and reducing
my planting, enabled myself to rest, annually, one third of my fields. And I
have already hauled out and mixed together, for the coming crop, 96,000
bushels of muck, and 48,000 bushels of manure from stables and stable yards,
hog and ox pens, &c., haying yet about 20,000 bushels more to carry out before
planting. [ shall not only endeavour to increase this amount of manure
every year hereafter, but also, by clearing and reducing the land in cul-
tivation, to rest, as nearly as may be requisite, each field, every other
_ year. Indeed, the management of land, after it is marled, is of the utmost
consequence to the efficiency and profit of marl. Though lime is itself a
portion of the food of plants, and therefore a manure, this is perhaps the very
least of its virtues. Its indirect operations are far more important. It is the
‘grand agent that prepares for the crop nearly all the food which the earth
furnishes. It is the purveyor general—no—the Farmer must fill that office:
it is the “ chef de cuisine” that selects the ingredients, mixes, and seasons

22

almost every dish to suit the delicate appetite of the growing plant. It is
from the materials placed in the soil by nature, or the industrious husband-
man, that this skillful artist draws the rich repasts it furnishes; and it couldno
more furnish them without these materials, than your cook could make your
soup without joints and spices, ‘The larder of the marl must then be amply
supplied. ‘The means of doing it are rest and manure. ‘The great gain.
to the farmer is, that having once engaged in his service this powerful, un-
tiring, and almost universal agent, he may safely exert himself to the utmost
of his ability to supply it with every thing necessary to carry on its important
operations. Seizing on whatever is valuable, it preserves it from waste—
combining with the utmost generosity the wisest economy, it not only yields
to the plant all it requires, but stimulates it to ask more, while it is inaccessi-
ble to demands from all other quarters.

There is no fancy in this—Theory and experiment unite to prove it true.
And I trust that no great length of time will elapse before marl shall have
written its own eulogy in indelible characters over all the broad fields of your
county.

Permit me to conclude this letter, for the great length of which I owe you
an apology, by returning my acknowledgments for the honor you have done
me in electing me an honorary member of your Society, and by wishing
each member of it the utmost success in his agricultural pursuits.

I am, very respectfully,
Your ob’t. serv’t.
J. H. HAMMOND.

Hamitton Rarrorp, Esq,

Corresponding Secretary of the Agricultural
Society of Jefferson Co., Georgia.

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