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main river, it is additionally necessary that the Bridgeport pumps be continuously operated.1

From causes already indicated, -namely, by the more perfect utilization of wastes and refuse which formerly added to soil and water contamination, and by thorough sanitary supervision and control, it is probable that the pollution of the Chicago River will be due mainly, in the future, to the sewage proper of the city. This, of course, will increase with the increase of population and the extension of the sewer system. But I estimate, that, at the present time, the river and its branches may be kept in a fair sanitary condition, and the sewage diluted so as to be inoffensive, by causing a flow of from forty-five to fifty thousand cubic feet per minute through the canal : sixty thousand cubic feet will probably be sufficient when the population has increased to seven hundred and fifty thousand. If, by the time the present capacity of the canal is reached, the proposed plan of converting it into a ship-canal has not been realized, it may be necessary to seek additional relief through the Des Plaines River. Pumping-works at the 'Ogden ditch,' discharging into the Des Plaines, may then be used to supplement the discharge into the canal; and for many years these two systems will be adequate to prevent any serious pollution of the Chicago River, will protect the water-supply from contamination, and will relieve neighboring communities along the canal and Illinois River from the nuisance heretofore frequently caused by the sewage-disposal of Chicago.

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THE soil, especially the first few inches or feet below the surface, is the ante-chamber of life, the laboratory in which operate incessantly the processes by which inert matter is prepared for the nourishment of life. It is this, because it is also the tomb of all terrestrial living matter. Here is the realization of the Phoenix-myth; the slow combustion of organic matter leaving a residuum, from which springs the new life of succeeding generations.

These processes of the transformation of matter are the work of the low forms of microscopic life which are known as bacteria, and are gifted with the capacity of enormous and immensely rapid multiplication. This world.

1 The Fullerton-Avenue conduit was constructed, and the pumping-works arranged, so as to discharge the contents of the north branch into the lake through the conduit, or to convey lake-water into the branch. The former method is contrary to the correct principles of the sewage-disposal of Chicago, and must ultimately be abandoned.

of microscopical life is vast as regards the distribution and number of its living entities. These minute organisms are known to be intimately connected with many of the fundamental processes of the organic world, and our knowledge of their range of activity is constantly increasing.

They may be considered practically to stand in close genetic relations to many diseases; but the question of absolute differentiation of forms with specific functions, or of the possibility of Protean functional characteristics among them, varying with their surroundings, is one of the present great problems of biology.

The great majority of pathologists now consider the infectious, and most of the contagious, diseases to be dependent on these low forms of life; and the tendency is, to consider that certain diseases or groups of diseases are produced only by specific forms of bacteria.

These organisms are wide-spread, especially the various forms that are associated with putrefaction and mould. Only on high mountains, and far from land on the ocean, is the air practically free from them. Elsewhere the air, water, and soil teem with them. Their abundance is necessarily proportionate to the amount of decomposing organic matter in the neighborhood, since they are themselves the scavengers, on which the processes of decomposition depend.

Few people realize what an important part the soil plays in our lives. The water we drink (unless from cisterns) has leached through it. The air we breathe is frequently loaded with its dust. It is in our food.

The soil is highly porous; and the interstices between the grains are filled with water or with air, ground-water' or 'ground-air.' The ground-air fluctuates with the varying barometric pressure, and with the rise and fall of the ground-water in rainy and dry seasons. The ground-water flows according to the common laws of hydrostatics, but with a movement retarded by friction.

A town on a river-flat is built over a continuous sheet of slowly moving subterranean water, and most houses are built where water is accessible within a few feet from the surface. In view of the fact that our wells and the cellars of our houses are in more or less close proximity to these centres of pollution, it was thought desirable to ascertain to what extent the different soils act as filters in arresting the spores of bacteria. This investigation,

which was carried out for the National board of health by the writer, assisted by Dr. Smyth, brought out very clearly three facts:

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I. All soils finer than very coarse sand have practically a continuous capacity for arresting the spores of bacteria from infected air filtering through them.

II. No soil, no matter how fine, can arrest and hold back the spores of bacteria contained in water. The experiment on which this statement rests consisted in filtering unsterilized water through one hundred feet of pipe filled with fine sand which had been sterilized

by heating to a red heat. This pipe was connected by an air-tight joint with a flask of sterilized beef-infusion, and the whole apparatus left for several weeks before use. The first drop of water that passed through these hundred feet of sand infected the beef-infusion, causing it to putrefy.

III. Neither bacteria nor their spores can detach themselves from a liquid or from a wet soil, and pass into the air, except through the conversion of the water into spray, or through the formation of dust by evaporation.

The chief practical inferences from these results are, that distances, even of hundreds of feet, between wells and cesspools, are no protection against infection, and that a dry or an alternately wet and dry cellar may be more dangerous than a permanently wet one.

These results emphasize the importance of an intelligent survey of the condition of the soil in selecting a home, and of a legislation prohibiting the pollution of the soil.

In many towns and cities, the privy-vaults and leaching cesspools of every house drain really into the sheet of ground-water: the soil arrests the coarse material, the grease and slime; but the swarming bacteria diffuse with ease, as much as the soluble chlorides and nitrates, and follow the flow wholly unobstructed. Into this same soil are sunk or driven the wells; and the water that is drawn for use is polluted in proportion to the number and proximity of the vaults and cesspools, on the one hand, and the thinness and sluggishness of the water-sheet, on the other. In the worst wells in daily use, the water is distinctly colored with sewage; but the most deadly water may carry only the germs of typhoid-fever or of dysentery, and be otherwise sparklingly clear, and so pure as to pass unchallenged through the most searching chemical analysis.

If the soil is polluted and very coarse gravel, this indraught, loaded with the spores of bacteria, will flow through the cellar to the warmer rooms. If the soil is polluted and fine, and the ground water-surface rises at any season to the level of the floor, or higher, it will

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evaporate as it oozes into the cellar, and leave an infected dust to be taken up into the circulation of the house-air. Similar results will follow from the leaching of the cesspool toward the cellar-wall, or from the filtration through the soil of sewage from a broken or leaky drain; which is very apt to exist in or just outside of the foundation-wall. The pollutions of soil and water already mentioned are of such a general character, that, with ordinary forethought, they can be guarded against; but there are others of a local character which are

not revealed to a general survey. In the growth of many of our cities, the natural topography is disregarded. Lowlands and marshes which are traversed by sewage-fed brooks are covered with a network of high-graded streets, which convert the blocks into sewage-basins, which come, in time, to underlie blocks of dwellings of all classes.

In other cases, low or marshy ground is made the dumping-ground of the city, and receives the sweepings of the street, the contents of the ash and garbage barrels, every thing, in fact, that cannot pass through the sewers or be sold. The entire material is loaded with organic matter which is kept in a state of very slow decomposition by moisture.

Some of the costliest dwellings of our cities rise upon such soil. We may take every precaution to avoid in our homes the dangers that arise from a polluted soil, and may yet fall victims to the filthy condition of remote places, over which we have no control.

Among many others there are two exceptionally frequent sources of danger of this kind. One of these is the farmer's well, which is rarely safe, and, when not used to adulterate milk, is used to rinse milk pans and cans, and leaves upon their surfaces a source of contamination. The other frequent instance is the use, by druggists, of water from wells or from cisterns, which are often any thing but sewage-proof. Throughout the country, and often in the cities, the use of only distilled water in compounding medicines is far from universal; and I have had analyses made of lime-water bought at a druggist's, which was highly contaminated with organic matter. The druggist's well, moreover, is the source of most of the soda-water throughout the country, as well as in many cities where the water-rates are high. A person having a harmless disturbance of the bowels, arising from a cold, is just in the condition to succumb to the dysentery or typhoid-fever lurking in the medicine or Vichy-water from the toomuch-trusted druggist.




AT a conference of state and municipal boards of health held at Washington last December, ten propositions were unanimously agreed to. The first of these is, that all surface-wells should be closed at the earliest possible moment.' This has special reference to the surface-wells in cities. Why do these wells deserve such sweeping condemnation? We have only to consider the conditions surrounding them, to have a reason suggested. In cities in which there are no sewers, it is well known that the discharges from the inhabitants are conveyed to cesspools, where they are allowed to remain indefinitely. Sometimes the contents of these cesspools are imperfectly removed sometimes they are not disturbed, a new cesspool being dug in the neighborhood of one which has become filled. They are rarely built carefully, but are usually merely holes in the ground, lined with sufficient stonework to prevent the earth from falling in. some cities they are dug in exactly the same way as the wells which are intended to supply drinking-water. The digging is in each case continued until water is reached. Communication is thus established with subterranean currents, and the refuse matter which finds its way into the cesspools is at least partly carried away. This saves some trouble; but what becomes of the refuse matter? Under very exceptional circumstances, it may find its way to some large body of water which is not used for drinking-purposes, and thus do no harm. If, however, there are wells in the neighborhood, the chances are in favor of the contents of the cesspools and of the wells becoming mixed. The larger the number of cesspools and of wells, the greater the danger of such a result. In a city not provided with sewers, therefore, the conditions are such as to lead almost certainly to contamination of the water of surface-wells with the contents of the cesspools. Besides this, there is the danger of contamination from surface-drainage, which cannot be avoided. The water which falls upon the ground, whether the ground be paved or not, sinks to a considerable extent below the surface, carrying with it such impurities as may be present. Such surface-water in cities, it is safe to say, is always contaminated. Some of it is sure to find its way into the wells.

This latter source of contamination is common to all cities, whether they are provided with sewers or not. While, however, the city which is provided with sewers is not subjected to exactly the same kind of danger as that first

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referred to above, the cases do not present as much difference as might at first be supposed." The sewers are generally leaky, and the soil in their vicinity becomes saturated with sewage. Thus they may contribute to the contamination of the well-waters. Of course, the danger of such contamination is not so great as when there are no sewers, but still it is quite sufficient to justify the condemnation of the surface-wells.

The waters of city wells have frequently been studied by chemists and biologists, and the results invariably show that contamination is the rule. In Brooklyn, N. Y., there were, in 1882, three hundred and sixteen wells. Chemical examination showed, "that, of this whole number, but seventeen furnished water fit for human consumption." Similar results have been reached in an examination of the water of the wells of Baltimore, where a few years ago there were between one and two hundred in use. The contamination of some of the waters examined was such as to show that very close connection must exist between the wells and cesspools. The testimony of all who have given special attention to the subject of the water of city wells is unanswerable. Not only does a consideration of the surrounding circumstances lead us to suspect that the water must be contaminated, but the most careful examinations, by those most capable of making the examinations, have shown that actually, and almost invariably, the water is badly contaminated.

It is an unfortunate fact, that, though the waters of city wells are generally impure, their external properties do not always reveal the impurity. Sometimes they do; and then it requires but a very slight hint as to the cause of the properties, to stop the further use of the water. Thus, for example, some years ago there was a spring in Baltimore, which, owing to its peculiar taste and odor, was regarded as a mineral spring. It was therefore fenced in, and covered, and generally treated like others of the class known as mineral springs.' It was afterwards found that very close connection existed between it and a neighboring cesspool; and the cause of the taste and odor which had given the water its reputation was thus revealed. It need not be added that the water ceased to be popular. More frequently these well-waters are clear, and without taste and odor, and, coming from greater depths than the service-water, they are generally cooler. Frequently, too, they are used for years, and many who use them continue in good health. There are, of course, in every community, many who are able to resist bad influences. They furnish

no evidence for or against the danger of using bad water. The influences are felt principally by the weaker members of a community.

As regards the specific objections which may be raised to using the water of city wells, it may be said, in the first place, that the evidence is pretty clear that water contaminated with sewage does at times give rise to low fevers. Though it is difficult to furnish satisfactory proof of the statement that the use of contaminated water tends to lower the general condition of health of those who habitually use it, those who have paid most attention to the subject unanimously agree that pure water is as important as pure air for the preservation of good health. One of the chief dangers in the use of water contaminated with sewage is, that, by establishing connection between the sick and the well, it contributes to the spread of some forms of epidemic disease. As is well known, it is now held by many of the highest authorities that in some diseases the organisms which are believed to be the active causes are given off from the patients with the alvine discharges. If, now, by any means, these organisms or their germs are introduced into the system of a well person, the diseased condition is set up. What more efficient method of distributing these organisms than drinking water which is contaminated with the contents of cesspools! Exactly what forms of disease may be spread in this way, it is difficult to say; but there is strong evidence in favor of the view that typhoid-fever and cholera are among them. Over and over again, outbreaks of typhoid-fever have been traced with practically absolute certainty to the use of water known to be contaminated by sewage. In regard to cholera, the evidence is quite sufficient to justify the destruction of all city wells. IRA REMSEN.


THE article by Mr. Hubbard, in Science of Nov. 4, 1884, on canal routes between the Atlantic and Pacific, discussed briefly the advantages of the three routes and methods proposed. The object of the present paper is to present the scientific and commercial reasons why the ship-railway across the Isthmus of Tehuantepec may be superior to either the Panama sea-level canal, or the Nicaragua lock canal.

It is estimated that $50,000,000 will be ample to put the ship-railway into operation for the transportation of vessels of 5,000 tons.

The estimated cost of the Nicaragua canal on a cash basis is $140,000,000, and of that at Panama, as high as $350,000,000.

The route via Panama, between Liverpool and San Francisco, is about 700 miles longer than by Tehuantepec; between New York and San Francisco, about 1,200 miles; and between New Orleans and San Francisco, about 2,000 miles. Probably 1,000 miles excess of distance would be a fair average.

The time in transit across the isthmus would be at least three days shorter at Tehuantepec than at Nicaragua for either a steamer or sailing-vessel. The Suez canal, which is 100 miles in length, delays a steamer 48 hours in transit, or her passage is at the rate of about two miles per hour: two-thirds of the distance is through the lakes, and there are no locks. At Nicaragua, about one-sixth of the distance only is through an open lake; and there will be from twelve to twenty locks, at each of which a vessel will be detained nearly an hour. The time required for passage, therefore, will be about four days; so that, although the total distance is shorter than at Panama, the time required for a steamer would be about the same.

In the article by Mr. Hubbard above referred to, reference has already been made to the favorable situation of Tehuantepec with reference to the trade-winds.


It is also hoped that the maintenance will cost much less per annum than that of either canal. The Panama canal being below the level of the sea, with the slopes of its enormous cuts exposed to the wash of the tropical rains, the difficulty of removing the material washed into its prism, and the controlling of the Chagres River, make the maintaining of the ship-channel difficult and expensive. Nicaragua the conditions are nearly similar. The ship-railway will not be subject at any point to the ravages of floods. It will be built over its entire length, on the solid ground, with excellent materials at hand for construction and maintenance. On either side is a natural harbor, which with small expense, by the construction of jetties, will give two excellent ports. The climate is remarkably healthy, and native labor abundant and cheap. It is located in a country which has a comparatively strong government.

The estimated total cost of maintenance and operation in lifting, hauling, and placing the vessel with its cargo in the water again, is less than thirty cents per ton of cargo carried.

The great doubt which must exist in the mind of the reader is in the practicability of lifting and hauling a loaded vessel. The method

proposed is very briefly this: to lift the vessel by an ordinary lifting-dock, distributing and equalizing completely the weight of the vessel by a system of hydraulic presses before the weight is brought upon the carriage which is to transport it. This is all done under the water, as the vessel rises out of it, and in such a manner as to be perfectly safe and easy for the vessel. The weight is finally placed upon the carriage in such a way that there is no more weight upon one wheel, or upon one part of the carriage in its length or width, than upon another. The weight upon no wheel will be over eight or nine tons, although they will be tested to twenty tons when manufactured. The whole load is transferred to the wheels by means of powerful springs, which will also be tested to twenty tons, and none of which will have imposed upon them in practice a weight of over eight and a half or nine tons. These springs not only give a perfect cushion for the vessel and carriage while being transported, but also serve to take up any slight irregularities there may be in the track. The system of supports designed, and shown in the working model, gives an area of support under the vessel from fifty to seventy-five times as great as that in the best lifting-dock in the world; and, moreover, these supports completely adjust themselves to the model of the vessel in each case. As it has been said frequently by practical experts in designing and building docks, and handling vessels in them, the desideratum is to have a sufficient number of adjustable supports, and this has been sought for in the plans for the work as shown in the model.

The railway road-bed will be about 50 feet in width; the width between the outer rails, about 30 feet. There will be six of these rails, weighing from 100 to 125 pounds per lineal yard. All six rails will be connected by a long steel-plated tie, set into two feet of broken stone ballast or concrete, as the case may be. The locomotive power as designed is to consist of engines of from 75 to 100 tons, each of which will haul at least 3,000 tons on a grade of as much as 40 feet to the mile; so that two, or at the most three, such locomotives will haul the maximum load. The grades are very light. Much of the line of railway is practically level. The maximum gradient, of which there is only one length of about 12 miles, is one per cent, or 52.8 feet per mile. The change between grades will be made by the ordinary vertical curve, but a very flat one,

one that will change from a straight line two inches in 400 feet. The railway is prac

tically straight, the minimum radius being 20 miles. The line as laid down on the isthmus has curves of from 20 to 53 miles radius. At five points on the line, in order to avoid heavy mountain cuttings or very high embankments, a change of direction will be made by floating turntables, - a simple and economical device in first cost and operation, on which the vessels will be turned about while resting on a cushion of water. The whole line has been very carefully surveyed, and is practically located. Careful examinations have been made to ascertain the character of the foundations, both for the road-bed and for the masonry structures. The result of these examinations shows that there is no bad or even questionable ground anywhere between the two termini. The accompanying map shows the topography of the country and the route of the railway, the river to be navigated and the harbors on the two sides.

It will be seen from the foregoing that the vessel, when lifted out of the water, is really water-borne on a system of columns of water under pressure, and that, in the position given by this hydraulic system, she is transported across the isthmus. It will also be seen and appreciated by every person who is accustomed to travel on the ocean, that the strain to the vessel by the methods proposed can never be so great as that which she must undergo every time she goes to sea. E. L. CORtHell.


THE results of Hulwa's numerous examinations of the waters of Breslau made during the years 1876-81, and which, up to that time, had appeared only in fragmentary official reports hardly obtainable even by specialists, were brought together into a single paper on the occasion of the German health exhibition in 1882-83. This paper, recently published, is of great value to all interested in water-supply.

As far as the well-waters are concerned, the numerical results are given only in selections and averages, and are, indeed, mainly of local interest. The story is essentially the same as may be told of any compactly built city, especially of the older parts, where the same houses have been occupied for hundreds of years. Of a hundred and fifty wells examined, less than ten per cent furnished water really good enough to use, and only two or three water which was above all suspicion.

Since the year 1871, Breslau has enjoyed a supply of water from the river Oder. The works are situated above the city, and the water is subjected to a thorough filtration through beds of sand and gravel.

Beiträge zur schwemmkanalisation und wasserversorgung der stadt Breslau. Von Dr. FRANZ HULWA. (Ergänzungshefte zum Centralblatt für allg. gesundheitspflege, I. ii. Bonn, 1884.)

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