Draining for Profit, and Draining for Health Part 17

As the circ.u.mstances under which upland water reaches lands of the cla.s.s under consideration vary with every locality, no specific directions for the treatment of individual cases can be given within the limits of this chapter; but the problem will rarely be a difficult one.

*The removal of the rain-fall and water of filtration* is the next point to be considered.

So far as the drainage of the land, in detail, is concerned, it is only necessary to say that it may be accomplished, as in the case of any other level land which, from the slight fall that can be allowed the drains, requires close attention and great care in the adjustment of the grades.

The main difficulty is in providing an outlet for the drains. This can only be done by artificial means, as the water must be removed from a level lower than high-water mark,-sometimes lower than low-water.

If it is only required that the outlet be at a point somewhat above the level of ordinary low-water, it will be sufficient to provide a sufficient reservoir, (usually a large open ditch,) to contain the drainage water that is discharged while the tide stands above the floor of the outlet sluice-way, and to provide for its outflow while the level of the tide water is below the point of discharge. This is done by means of sluices having self-acting valves, (or tide-gates,) opening outward, which will be closed by the weight of the water when the tide rises against them, being opened again by the pressure of the water from within, as soon the tide falls below the level of the water inside of the bank.

The gates and sluices may be of wood or iron,-square or round. The best would be galvanized iron pipes and valves; but a square wooden trunk, closed with a heavy oak gate that fits closely against its outer end, and moves freely on its hinges, will answer capitally well, if carefully and strongly made. If the gate is of wood, it will be well to have it lie in a slightly slanting position, so that its own weight will tend to keep it closed when the tide first commences to rise above the floor, and might trickle in, before it had acquired sufficient head to press the gate against the end of the trunk.

As this outlet has to remove, in a short time, all of the water that is delivered by the drains and ditches during several hours, it should, of course, be considerably larger than would be required for a constantly flowing drain from the same area; but the immense gates,-large enough for a ca.n.a.l lock,-which are sometimes used for the drainage of a few acres of marsh, are absurd. Not only are they useless, they are really objectionable, inasmuch as the greater extent of their joints increases the risk of leakage at the time of high water.

The channel for the outflow of the water may sometimes, with advantage, be open to the top of the d.y.k.e or dam,-a ca.n.a.l instead of a trunk; but this is rarely the better plan, and is only admissible where the discharge is into a river or small bay, too small for the formation of high waves, as these would be best received on the face of a well sodded, sloping bank.

The height, above absolute low water, at which the outlet should be placed, will depend on the depth of the outlet of the land drain, and the depth of storage room required to receive the drainage water during the higher stages of the tide. Of course, it must not be higher than the floor of the land drain outlet, and, except for the purpose of affording storage room, it need not be lower, although all the drainage will discharge, not only while the tide water is below the bottom of the gate, but as long as it remains lower than the level of the water inside. It is well to place the mouth of the trunk nearly as low as ordinary low-water mark. This will frequently render it necessary to carry a covered drain, of wood or brick, through the mud, out as far as the tide usually recedes,-connected with the valve gate at the outlet of the trunk, by a covered box which will keep rubbish from obstructing it, or interfering with its action.

_When the outlet of the land-drains is below low-water mark_, it is of course necessary to pump out the drainage water. This is done by steam or by wind, the latter being economical only for small tracts which will not bear the cost of a steam pump. Formerly, this work was done entirely by windmills, but these afford only an uncertain power, and often cause the entire loss of crops which are ready for the harvest, by obstinately refusing to work for days after a heavy rain has deluged the land. In gra.s.s land they are tolerably reliable, and on _small_ tracts in cultivation, it is easy, by having a good proportion of open ditches, to afford storage room sufficient for general security; but in the reclaiming of large areas, (and it is with these that the work is most economical,) the steam pump may be regarded as indispensable. It is fast superseding the windmills which, a few years ago, were the sole dependence in Holland and on the English Fens. The magnitude of the pumping machinery on which the agriculture of a large part of Holland depends, is astonishing.

There are such immense areas of salt marsh in the United States which may be tolerably drained by the use of simple valve gates, discharging above low-water mark, that it is not very important to consider the question of pumping, except in cases where owners of small tracts, from which a sufficient tidal outlet could not be secured, (without the concurrence of adjoining proprietors who might refuse to unite in making the improvement,) may find it advisable to erect small pumps for their own use. In such cases, it would generally be most economical to use wind-power, especially if an accessory steam pump be provided for occasional use, in emergency. Certainly, the tidal drainage should first be resorted to, for when the land has once been brought into cultivation, the propriety of introducing steam pumps will become more apparent, and the outlay will be made with more confidence of profitable return, and, in all cases, the tidal outlet should be depended on for the outflow of all water above its level. It would be folly to raise water by expensive means, which can be removed, even periodically, by natural drainage.

When pumps are used, their discharge pipes should pa.s.s through the embankment, and deliver the water at low-water mark, so that the engine may have to operate only against the actual height of the tide water. If it delivered above high-water mark, it would work, even at low tide, against a constant head, equal to that of the highest tides.

CHAPTER X. - MALARIAL DISEASES.

So far as remote agricultural districts are concerned, it is not probable that the mere question of health would induce the undertaking of costly drainage operations, although this consideration may operate, in connection with the need for an improved condition of soil, as a strong argument in its favor. As a rule, "the chills" are accepted by farmers, especially at the West, as one of the slight inconveniences attending their residence on rich lands; and it is not proposed, in this work, to urge the evils of this terrible disease, and of "sun pain," or "day neuralgia," as a reason for draining the immense prairies over which they prevail. The diseases exist,-to the incalculable detriment of the people,-and thorough draining would remove them, and would doubtless bring a large average return on the investment;-but the question is, after all, one of capital; and the cost of such draining as would remove fever-and-ague from the bottom lands and prairies of the West, and from the infected agricultural districts at the East, would be more than the agricultural capital of those districts could spare for the purpose.

In the vicinity of cities and towns, however, where more wealth has acc.u.mulated, and where the number of persons subjected to the malarial influence is greater, there can be no question as to the propriety of draining, even if nothing but improved health be the object.

Then again, there are immense tracts near the large cities of this country which would be most desirable for residence, were it not that their occupancy, except with certain constant precautions, implies almost inevitable suffering from fever-and-ague, or neuralgia.

Very few neighborhoods within thirty miles of the city of New York are entirely free from these scourges, whose influence has greatly r.e.t.a.r.ded their occupation by those who are seeking country homes; while many, who have braved the dangers of disease in these localities, have had sad cause to regret their temerity.

Probably the most striking instance of the effect of malaria on the growth and settlement of suburban districts, is to be found on Staten Island.

Within five miles of the Battery; accessible by the most agreeable and best managed ferry from the city; practically, nearer to Wall street than Murray Hill is; with most charming views of land and water; with a beautifully diversified surface, and an excellent soil; and affording capital opportunities for sea bathing, it should be, (were it not for its sanitary reputation, it inevitably would be,) one vast residence-park.

Except on its extreme northern end, and along its higher ridges, it has,-and, unfortunately, it deserves,-a most unenviable reputation for insalubrity. Here and there, on the southern slope also, there are favored places which are unaccountably free from the pest, but, as a rule, it is, during the summer and autumn, unsafe to live there without having constant recourse to preventive medication, or exercising unusual and inconvenient precautions with regard to exposure to mid-day sun and evening dew. There are always to be found attractive residences, which are deserted by their owners, and are offered for sale at absurdly low prices. There are isolated instances of very thorough and very costly draining, which has failed of effect, because so extensive a malarial region cannot be reclaimed by anything short of a systematic improvement of the whole.

It has been estimated that the thorough drainage of the low lands, valleys and ponds of the eastern end of the island, including two miles of the south sh.o.r.e, would at once add $5,000,000 to the market value of the real estate of that section. There can be no question that any radical improvement in this respect would remove the only obstacle to the rapid settlement of the island by those who wish to live in the country, yet need to be near to the business portion of the city. The hope of such improvement being made, however, seems as remote as ever,-although any one at all acquainted with the sources of miasm, in country neighborhoods, can readily see the cause of the difficulty, and the means for its removal are as plainly suggested.

Staten Island is, by no means, alone in this respect. All who know the history of the settlement of the other suburbs of New York are very well aware that those places which are free from fever-and-ague and malarial neuralgia, are extremely rare.

The exact cause of fever-and-ague and other malarial diseases is unknown, but it is demonstrated that, whatever the cause is, it is originated under a combination of circ.u.mstances, one of which is undue moisture in the soil. It is not necessary that land should be absolutely marshy to produce the miasm, for this often arises on cold, springy uplands which are quite free from deposits of muck. Thus far, the attention of scientific investigators, given to the consideration of the origin of malarial diseases, has failed to discover any well established facts concerning it; but there have been developed certain theories, which seem to be sustained by such knowledge as exists on the subject.

Dr. Bartlett, in his work on the Fevers of the United States, says:-"The essential, efficient, producing cause of periodical fever,-the poison whose action on the system gives rise to the disease,-is a substance or agent which has received the names of _malaria_, or _marsh miasm_. The nature and composition of this poison are wholly unknown to us. Like most other a.n.a.logous agents, like the contagious principle of small-pox and of typhus, and like the epidemic poison of scarletina and cholera, they are too subtle to be recognized by any of our senses, they are too fugitive to be caught by any of our contrivances.

"As always happens in such cases and under similar circ.u.mstances, in the absence of positive knowledge, we have been abundantly supplied with conjecture and speculation; what observation has failed to discover, hypothesis has endeavored and professed to supply. It is quite unnecessary even to enumerate the different substances to which malaria has been referred. Amongst them are all of the chemical products and compounds possible in wet and marshy localities; moisture alone; the products of animal and vegetable decomposition; and invisible living organisms. * * *

* Inscrutable, however, as the intimate nature of the substances or agents may be, there are some few of its laws and relations which are very well ascertained. One of these consists in its connection with low, or wet, or marshy localities. This connection is not invariable and exclusive, that is, there are marshy localities which are not malarious, and there are malarious localities which are not marshy; but there is no doubt whatever that it generally exists."

In a report to the United States Sanitary Commission, Dr. Metcalfe states, that all hypotheses, even the most plausible, are entirely unsupported by positive knowledge, and he says:-

"This confession of ignorance still leaves us in possession of certain knowledge concerning malaria, from which much practical good may be derived.

"1st. It affects, by preference, low and moist localities.

"2d. It is almost never developed at a lower temperature than 60 Fahrenheit.

"3d. Its evolution or active agency is checked by a temperature of 32.

"4th. It is most abundant and most virulent as we approach the equator and the sea-coast.

"5th. It has an affinity for dense foliage, which has the power of acc.u.mulating it, when lying in the course of winds blowing from malarious localities.

"6th. Forests, or even woods, have the power of obstructing and preventing its transmission, under these circ.u.mstances.

"7th. By atmospheric currents it is capable of being transported to considerable distances-probably as far as five miles.

"8th. It may be developed, in previously healthy places, by turning up the soil; as in making excavations for foundations of houses, tracks for railroads, and beds for ca.n.a.ls.

"9th. In certain cases it seems to be attracted and absorbed by bodies of water lying in the course of such winds as waft it from the miasmatic source.

"10th. Experience alone can enable us to decide as to the presence or absence of malaria, in any given locality.

"11th. In proportion as countries, previously malarious, are cleared up and thickly settled, periodical fevers disappear-in many instances to be replaced by the typhoid or typhus."

La Roche, in a carefully prepared treatise on "Pneumonia; its Supposed Connection with Autumnal Fevers," recites various theories concerning the mode of action of marsh miasm, and finds them insufficient to account for the phenomena which they produce. He continues as follows:-

"All the above hypotheses failing to account for the effects in question, we are naturally led to the admission that they are produced by the morbific influence of some special agent; and when we take into consideration all the circ.u.mstances attending the appearance of febrile diseases, the circ.u.mscribed sphere of their prevalence, the suddenness of their attack, the character of their phenomena, etc., we may safely say that there is nothing left but to attribute them to the action of some poison dissolved or suspended in the air of the infected locality; which poison, while doubtless requiring for its development and dissemination a certain degree of heat, and terrestrial and atmospheric moisture, a certain amount of nightly condensation after evaporation, and the presence of fermenting or decomposing materials, cannot be produced by either of these agencies alone, and though indicated by the chemist, betrays its presence by producing on those exposed to its influence the peculiar morbid changes characterizing fever."

He quotes the following from the Researches of Dr. Chadwick:-

"In considering the circ.u.mstances external to the residence, which affect the sanitary condition of the population, the importance of a general land-drainage is developed by the inquiries as to the cause of the prevalent diseases, to be of a magnitude of which no conception had been formed at the commencement of the investigation. Its importance is manifested by the severe consequences of its neglect in every part of the country, as well as by its advantages in the increasing salubrity and productiveness wherever the drainage has been skillful and effectual."

La Roche calls attention to these facts:-That the acclimated residents of a malarious locality, while they are less subject than strangers to active fever, show, in their physical and even in their mental organization, evident indications of the ill effects of living in a poisonous atmosphere,-an evil which increases with successive generations, often resulting in a positive deterioration of the race; that the lower animals are affected, though in a less degree than man; that deposits of organic matter which are entirely covered with water, (as at the bottom of a pond,) are not productive of malaria; that this condition of saturation is infinitely preferable to imperfect drainage; that swamps which are shaded from the sun's heat by trees, are not supposed to produce disease; and that marshes which are exposed to constant winds are not especially deleterious to persons living in their immediate vicinity,-while winds frequently carry the emanations of miasmatic districts to points some miles distant, where they produce their worst effects. This latter statement is substantiated by the fact that houses situated some miles to the leeward of low, wet lands, have been especially insalubrious until the windows and doors on the side toward the source of the miasm were closed up, and openings made on the other side,-and thenceforth remained free from the disease, although other houses with openings on the exposed sides continued unhealthy.

The literature relating to periodical fevers contains nothing else so interesting as the very ingenious article of Dr. J. H. Salisbury, on the "Cause of Malarious Fevers," contributed to the "American Journal of Medical Science," for January, 1866. Unfortunately, while there is no evidence to controvert the statements of this article, they do not seem to be honored with the confidence of the profession,-not being regarded as sufficiently authenticated to form a basis for scientific deductions. Dr.

Salisbury claims to have discovered the cause of malarial fever in the spores of a very low order of plant, which spores he claims to have invariably detected in the saliva, and in the urine, of fever patients, and in those of no other persons, and which he collected on plates of gla.s.s suspended over all marshes and other lands of a malarious character, which he examined, and which he was never able to obtain from lands which were not malarious. Starting from this point, he proceeds, (with circ.u.mstantial statements that seem to the unprofessional mind to be sufficient,) to show that the plant producing these spores is always found, in the form of a whitish, green, or brick-colored incrustation, on the surface of fever producing lands; that the spores, when detached from the parent plant, are carried in suspension _only in the moist exhalations of wet lands_, never rising higher, (usually from 35 to 60 feet,) nor being carried farther, than the humid air itself; that they most acc.u.mulate in the upper strata of the fogs, producing more disease on lands slightly elevated above the level of the marsh than at its very edge; that fever-and-ague are never to be found where this plant does not grow; that it may be at once introduced into the healthiest locality by transporting moist earth on which the incrustation is forming; that the plant, being introduced into the human system through the lungs, continues to grow there and causes disease; and that _quinia_ arrests its growth, (as it checks the multiplication of yeast plants in fermentation,) and thus suspends the action of the disease.

Probably it would be impossible to prove that the foregoing theory is correct, though it is not improbable that it contains the germ from which a fuller knowledge of the disease and its causes will be obtained. It is sufficient for the purposes of this work to say that, so far as Dr.

Salisbury's opinion is valuable, it is,-like the opinion of all other writers on the subject,-fully in favor of perfect drainage as the one great preventive of all malarial diseases.

_The evidence of the effect of drainage_ in removing the cause of malarial diseases is complete and conclusive. Instances of such improvement in this country are not rare, but they are much less numerous and less conspicuous here than in England, where draining has been much more extensively carried out, and where greater pains have been taken to collect testimony as to its effects.

If there is any fact well established by satisfactory experience, it is that thorough and judicious draining will entirely remove the local source of the miasm which produces these diseases.