cause they require time to pulverize them, before their salts can mix with the earth to impregnate it. ing. Sand, and the smaller kind of sea weeds, will The consequence of this is, that their manure is lastenrich land for six or seven years: and shells, coral, and other hard bodies, will continue many years long

er.

called, than any of the substances described under these bodies are hard, the improvement is not the first that name, in the foregoing quotations. This or second year after they are laid on the ground, bemanure is almost a pure calcareous earth, being formed of the remains of small fresh-water shells deposited on what were once the bottoms of lakes, but which have since become covered with bog or peat soil. If I may judge from our beds of muscle shells, (to which this manure seems to bear most resemblance,) much putrescent animal matter is combined with, and serves to give additional value to these bodies of shells. This kind of manure is sold in Scotland by the bushel, at such prices, as show that it is very highly prized. It seems to be found but in few situations, and though called a kind of marl, is never meant when that term alone is used generally.

"In some countries fossil shells have been used with success as manure; but they are not near so full of salts, as those shells which are taken from the sea shore; and therefore the latter are always to be preferred. Sea sand is much used as manure in Cornwall. The best is that which is intimately mixed with coral."-p. 21.

After stating the manner in which this "excellent ex-manure" is taken up from the bottom, in barges, its character is thus continued:

The opinions expressed in the foregoing tracts, prove sufficiently that it was not the ignorant cultivators only, who either did not know of, or attached no importance to the calcareous ingredient in marl: and it was impossible, that from any number of such authors, an American reader could learn that either the object, or the effect of marling, was to render a soil more calcareous or that our bodies of fossil shells resembled marl in character, or in operation, as a manure. Of this, the following quotation will furnish striking proof -and the more so, as the author refers frequently to the works of Anderson, and of Young, who treated of marl and calcareous manures, in a more scientific manner than had been usual. This author, Bordley, cannot be justly charged with inattention to the instruction to be gained from books: for his greatest fault, as an agriculturist, is his fondness for applying the practices of the most improved husbandry of England, to our lands and situations, however different and unsuitablewhich he carries to an extent that is ridiculous as theory, and would be ruinous to the farmer who should so shape his general practice.

6. "I farmed in a country [the Eastern Shore of Maryland] where habits are against a due attention to manures: but having read of the application of marl as a manure, I inquired where there was any in the peninsula of the Chesapeake, in vain. My own farm had a grayish clay, which to the eye was marl: but because it did not effervesce with acids, it was given up, when it ought to have been tried on the land, especially as it rapidly crumbled and fell to mud, in water, with some appearance of effervescence."-Bordley's Husbandry, 2nd ed. p. 55.

it [i. e. the sea sand mixed with coral, as it may happen,] gives the heat of lime, and the fatness of oil, to the land it is laid upon. Being more solid than shells, it conveys a greater quantity of fermenting earth in equal space. Besides, it does not dissolve in the ground so soon as shells, but decaying more gradually, continues longer to impart its warmth to the juices of the earth.”

Here are described manures which are known to be calcareous, which are strongly recommended

but solely for their supposed mechanical effect in separating the parts of close clays, and on account of the salts derived from sea water, which they contain. Indeed, no allusion is made to any supposed value, or even to the presence of calcareous earth, which forms so large a proportion of these manures: and the fossil shells, (in which that ingredient is more abundant, more finely reduced, and consequently more fit for both immediate and durable effects,) are considered as less efficacious than solid sea shells-and inferior to sea sand. All these substances, besides whatever service their salts may render, are precisely the same kind of calcareous manure, as our beds of Yet neifossil shells furnish in a different form. ther here nor elsewhere, does the author intimate that these manures and marl have similar powers for improving soils.

The foregoing quotations show what opinions have been expressed by English writers of reputation-and what opinion would be formed by a general reader of these and other agricultural works, of the nature of what is called marl, in That peninsula, through which Mr. Bordley in England, as well as what is so named in this part vain inquired for marl, has immense quantities of of our country. I do not mean that other authors the fossil shells which we so improperly call by have not thought more correctly, and sometimes that name. But as his search was directed to marl expressed themselves with precision on this subas described by English authors-and not to cal-ject. Mineralogists define marl, to be a calcareous careous earth simply-it is not to be wondered at that he should neither find the former substance, nor attach enough importance to the latter, to induce the slightest remark on its probable use as

manure.

7. The Practical Treatise on Husbandry, among the directions for improving clay land, has what follows.

"Sea sand and sea shells are used to great advantage as a manure, chiefly for cold strong [i. e. clay] land, and loam inclining to clay. They separate the parts; and the salts which are contained in them are a very great improvement to the land. Coral, and such kind of stony plants which grow on the rocks, are filled with salts, which are very beneficial to land. But as

clay-and in this correct sense, the term is used by Davy, and other chemical agriculturists. Such authors as Young, and Sinclair, also could not have been ignorant of the true composition of marl-yet even they have used so little precision or clearness, when speaking of the effects of marling, that their statements, (however correct they may be in the sense they intended them,) conv no exact information, and have not served to e move the erroneous impressions made by the great body of their predecessors. Knowines Young did [see first quotation] the confusion in

* Cleaveland's Mineralogy.

"It is extremely difficult to discover, from the knowledge at present possessed by the public, what ought to be the quantity of calcareous earth in a soil. The 10. The section on marl (page 402, of the by Bergman, 30 per cent.; by Dr. Fordyce, 2 per cent.; best specimen analyzed by Giobert, had 6 per cent.; same work) gives concise statements of its appli-a rich soil, quoted by Mr. Davy, in his lecture at the cation, with general notices of its effects, on near Royal Institution, 11 per cent. This is an inquiry, fifty different parishes, neighborhoods, or separate concerning which I have made many experiments, farms. Among all these, the only statements from which the calcareous nature of the manure may be gathered, are, (page 406) of a marl that "ferments strongly with acids"-another, (page 409,) that marling at a particular place destroys Sorel-and (page 410) that the marl is generally calcareous, and that that containing the most clay, at the least calcareous earth, is preferred by most persons, but not by all.

[i. e. vegetable or animal] matter; of that organic matter which is [partly] convertible into hydrogen gas. If the farmer finds, by experiment, that his soil has but a small quantity of organic matter, or knows by his practice that it is poor, and not worth more than 10s., 15s. or 20s. an acre, he may then conclude that there ought to be 20 per cent. of calcareous earth in it; but if, on the contrary, it abound with organic matter, and be worth in practice a much larger rent, in that case his marl cart will not be called for, though there be but five per cent. or even less, of calcareous matter."-Young's Essay on

Manures-Sect. 2.

renders the soil a caput mortuum, capable of neither corn nor grass; of which, there are too many examples in Scotland, &c. Gentleman Farmer, p. 378. 15. Yet the last writer (Lord Kames) elsewhere states, (at page 379) that as much clay marl as contains 1500 bolls, (on 9000 bushels) of pure calcareous earth to the acre, is not an overdose in Scotland.

16. "Marl. Of this substance, there are four sorts, rock-slate-clay-and shell marl. The three former are of so heavy a nature that they are seldom conveyed It is scarcely necessary to show, that the opin- to any distance; though useful when found below a ion of calcareous matter, being needed in larger lighter soil. But shell marl is specifically lighter, and quantities in proportion to the deficiency of pu- and partially decayed shells of fish,) which may be consists entirely of calcareous matter, (the broken trescent matter, is directly opposed to the reasoning applied as a top dressing to wheat and grass, when it of this essay. If a poor soil were made to contain would be less advantageous to use quicklime." [This twenty per cent. of calcareous matter, by applying is the kind of manure referred to in extract 5, and lime, chalk, or marl, the quantity and the expense there more particularly described.] "In Lancashire would be so enormous as not to be justified by any and Cheshire, clay, or red marl, is the great source possible return-and in truth, would lessen, rather of fertilization, &c."-"The quantity used is enormous; than increase, the product of a poor soil. The fact in many cases about three hundred middling cart loads named as strange, by Young, that some rich soils per acre, and the fields are sometimes so thickly covercontain very small, and others very large propor-ed as to have the appearance of a red soiled fallow, tions of calcareous earth, is easily explained. If a fresh ploughed."- -Sinclair's Code of Agriculture, natural soil contains any excess of calcareous earth, American Ed. (Hartford) p. 138. even though but one per cent., it shows that there is that much to spare after serving every purpose of neutralizing acids and combining with putrescent matter. If there were twenty per cent. more of calcareous matter, it would be useless, until met by an additional supply of putrescent matter. Young's statement that some poor soils agree precisely with other rich soils, in their contents of calcareous earth, does not necessarily contradict my doctrine that a proper proportion of calcareous earth will enable any soil to become rich, either in a state of nature, or under mild cultivationand for the following reasons:

This account of the Lancashire improvements made by red clay marl, closes with the statement that "the effects are represented to be beneficial in the highest degree"-which is fully as exact an account of profit, or increased production, as we can obtain of any other marling. Throughout, there is no hint as to the calcareous constituents of the soil, or the manure, or whether either rock, clay or slate marls generally, are valuable for that, or for other reasons; nor indeed could we guess that they contained any calcareous earth, but for their being classed, with many other substances, under the general head of calcareous manures.

chalky soils, are either by the application of clayey 17. "The means of ameliorating the texture of and sandy loams, pure clay, or marl."-"The chalk stratum sometimes lies upon a thick vein of black tenacious marl, of a rich quality, which ought to be dug up and mixed with the chalk."-Code of Agriculture, p. 19.

18. Dickson's Farmer's Companion.-The author recommends "argillaceous marl" for the improvement of chalky soils: and for sandy soils, "where the calcareous principle is in sufficient abundance, argillaceous marl, and clayey loams," are recommended as manures.

14. 1st. The correctness of Young's analyses may be well doubted--and if he used the then usual process for separating calcareous earth, he was obliged to be incorrect, on account of its unavoidable imperfection, as has been already explained at page 18. 2d. It cannot be known positively what was the original, state of fertility of most cultivated soils in England, nor whether they were subjected to exhausting or improving cultivation, for centuries before our information from history begins. 3d. Lime has been there used for a long time, and to great extent; and chalk and marl were applied as manures during the time of the Roman conquest, as stated by Pliny, (say 1700 years ago)-so that it cannot be always known whether a soil has received its calcareous ingredient from nature, or the industry of man. 4th. It is known that severe cropping after liming, and also excessive doses of calcareous earth, have render- The evident intention and effect of the marling ed land almost barren: of which the following ex-recommended in all the three last extracts, is to tracts offer sufficient proof:— diminish the proportion of calcareous earth in the soil.

19. "Chalky loam. The best manure for this soil is clay, or argillaceous marl, if clay cannot be had; because this soil is defective principally in the argillaceous ingredient.”—Kirwan on Manures, p. 80.

"Before 1778, [in East Lothian] the outfield did not receive any dung except what was left by the animals 20. In a Traveller's Notes of an agricultural grazed upon it. In many cases, outfield land was tour in England, in 1811, which is published in limed; and often with singular advantage. The after the third volume of the Edinburgh Farmer's management was uniformly bad; it being customary to Magazine, the following passages relate to Mr. crop the limed outfield with barley and oats successive-Coke's estate, Holkham, and to Norfolk ger ely, so long as the crop was worth cutting. In this way rally. numerous fields suffered so severely as to be rendered almost steril for half a century afterwards." Farmer's Magazine, p. 53, Vol. 12.

"An overdose of shell marl, laid perhaps an inch thick, produces for a time large crops. But at last it

"Holkham.-The soil here is naturally very poor, being a mixture of sand, chalk, and flint stones, with apparently little mixture of argillaceous earth—// « subsoil, chalk or limestone every where." Page 6.

"As the soil of the territory [of Norfolk generally] through which I passed, seems to have a sufficient mixture of calcareous earth naturally, I learn they do not often lime their lands; but clay marl has been found to have the most beneficial consequences on most of the Norfolk soils."-p. 487.

21. "In Norfolk, they seem to value clay more than marl, probably because their sandy soils already contain calcareous parts.”—Kirwan on Manures, p. 87.

From this and the preceding quotation it would follow, that the great and celebrated improvements in Norfolk, made by marling, had actually operated to lessen the calcareous proportion of the soil, instead of increasing it. Or, (as may be deduced from what will follow,) if so scientific and diligent an inquirer as Kirwan, was deceived on this very important point, it furnishes additional proof of the impossibility of drawing correct conclusions on this subject from European books-when it is left doubtful, whether the most extensive, the most profitable, and the most celebrated improvements by "marling," in Europe, have in fact served to

make the soil more or less calcareous.

Most of the extracts which I have presented, are from British agriculturists of high character and authority. If such writers as these, while giving long and (in some respects) minute statements of marl, and marling, omit to tell, or leave their readers to doubt, whether the manure or the soil is the most calcareous-or what proportions of calcareous earth, or whether any, is present in either-then have I fully established that the American reader who may attempt to draw instruction from such sources, as to the operation, effects and profits of either marl or calcareous manures, in general will be more apt to be deceived and misled, than enlightened.

Chalk marl of Thorp-market, contained,
Soft chalk of Thorp-next-Norwich,
Hard chalk of Swaffham, almost pure-
Clay marl of Hemsby,

85 100 98 100

43 100

22. Of these he spoke previously and in general terms, thus:

"The central and northern parts of the district abound, universally, with a whitish-colored chalk marl; while the Fleg Hundreds, and the eastern coast, are equally fortunate in a gray-colored clay marl.

"The first has, in all probability, been in use as a size now going to decay in pits which have obviously manure many centuries: there are oaks of considerable been heretofore in use, and which, perhaps, still remain in use, as marlpits.

"The use of clay marl, as a manure, seems to be a much later discovery; even yet, there are farmers who are blind to its good effect; because it is not marl, but "clay;" by which name it is universally known.

"The name, however, would be a thing of no import, were it not indiscriminately applied to unctuous earths in general whether they contain, or not, any portion of calcareous matter. Nothing is "marl" which is not white; largely indebted to its fertilizing quality, her husbandfor, notwithstanding the county has been so long and so men, even in this enlightened age, remain totally ig norant of its distinguishing properties: through which want of information much labor and expense is frequently thrown away.

"One man seeing the good effect of the Fleg clay, for instance, concludes that all clays are fertile, and finding a bed of strong brick earth upon his farm, falls to work, at a great expense, to "claying:"-while anall clays are unprofitable; and, in consequence, is at an other observing this man's miscarriage, concludes that expense, equally ill applied, of fetching "marl" from a great distance; while he has, perhaps, in his own farm, if judiciously sought after, an earth of a quality equally fertilizing with that he is throwing away his time and his money in fetching. Marshall's Norfolk Vol. I. p. 16.

I have now to refer to an author, whose works, well known as they may be to others, had not come under my view until after the publication of most of the foregoing extracts. Otherwise, Marshall would have intimated whether the Norfolk soils were Yet it is remarkable, that Marshall should not have been stated as an exception to the general naturally calcareous, (as the two writers just besilence of British authors as to the true and pre-fore quoted declare,) or not-and therefore we are cise nature of what they treated of as marl. But still left to guess whether these manures served to though he has not been, like others, so faulty as to leave in doubt what was the character and value increase the calcareous quality of soils already of the marls, of which he spoke, and the nature possessing that quality in a high degree or to of their operation on the soils to which they were give it to soils devoid of it before. applied-still no other writer furnishes stronger Other passages will now be quoted from the proof of the general ignorance and disregard of same, and from other similar works of Marshall's, the nature of marls and calcareous manures, and and operation of the marls sometimes prized, to show the prevailing ignorance of the ingredients, of their mode of operation; and even the author himself is not free from the same charge, as will be and sometimes contemned, with as little reason in shown. I shall quote more at length from Mar- the one case as the other, by farmers in various shall, because he presents the strongest opposition parts of England. to what I have stated as to the general purport of publications on marling: and also, because, whatever may be their character, there is much to interest the reader in his accounts of the opinions and practices of those who have used calcareous manures longest, and most extensively, although without knowing what they were doing.

a

much shallower soil, not deeper than the plough goes; 23. "The principal part of his estate, however, is of and its present very amazing fertility he ascribes in a great measure, to his having clayed it. Indeed to this species of improvement the fertility of the Fleg Hundred is allowed to be principally owing.

"Mr. F. gave me an opportunity of examining his clay pit, which is very commodious; the uncallow is trifling, and the depth of the bed or jam he has not been able to ascertain. It is worked, at present, about ten or twelve feet deep.

In his Rural Economy of Norfolk, the "marls" and "clays" most used in the celebrated improvements of that county are minutely described, and the chemical composition stated-showing that "The color of the fossil, when moist, is dark brown, both are highly calcareous. Of the "marls," or chalks, most used for manure in Norfolk, he analy-color lighter than that of fuller's earth; on being exinterspersed with specks of white; and dries to a zed three specimens, and one of clay, and found posed to the air, it breaks into small die-like pieces. the proportions of pure calcareous matter as follows:

"From Mr. F's. account of the manner of its acting, and more particularly from its appearance, I judged it

to be a brown marl, rather than a clay; and, on trying specimens analyzed, is an inmense excavation, out of it in acid, it proves to be strongly calcareous; effer- which many thousand loads have been taken. vescing, and hissing, more violently than most of the "And the marls of this neighborhood (which mostly white marls of this neighborhood: and what is still differ in appearance from those described, having genmore interesting, the Hemsby clay is equally turbu-erally that of a blood-red clay, interlayered, and somelent in acid as the Norwich marl, which is brought by times intermingled, with a white gritty substance) are water forty miles into this country, at the excessive equally poor in calcareosity. expense of four shillings a load upon the staith; besides the land carriage. [The strength of this Hemsby clay is stated above.]