aqueducts, which bring it from pure sources at a distance beyond their contaminating influences, is of course much better than that from city wells. This last, we believe, is a fruitful source of disease and death; its relation to the epidemic and endemic diseases is of the closest character. We shall, as briefly as possible, treat upon the well-water of great cities; and, for the purpose of showing the manner in which well-water may be contaminated, we will speak of that which is supplied by the wells in the city of St. Louis.

The clay that underlies this city is fissured from the surface to the rock below, which is found at a depth varying from twenty to a hundred feet. Consequently, surface-water, with all the impurity it has gathered, readily finds its way to the surface of the rock, carrying with it any substances that may be entirely or partially soluble, and opening a channel for the passage of the many foul fluids that abound in a great city.

The privies of the city are built of brick without the use of cement or mortar, in order that the fluid contents of the vaults may readily escape. They ultimately find their way to the rock beneath. The sewers also are by no means water-tight; fluids readily escape from fractures, or through the porous bricks, when laid in cement or mortar; or, when the quantity of cement or mortar is insufficient, through interstices between the bricks. It is well known also that gas from defective gas-pipes saturates the earth in the immediate vicinity of the defect; and, as this is more or less soluble in water, we have here a third source of impurity in the water found near the surface of the rock.

Besides other modes of polluting the water beneath, the city is traversed by several streams of running water and upon their banks may be found slaughter-houses, glue manufactories, and soap and candle factories; the refuse of these is thrown into the streams. Again, the surface of our city is more or less broken by hollows: these are either sink-holes, which the surface-water has made in its passage to the rock below, or they § VII. -6

are made in the process of the construction of streets. These holes are filled with various abominations; the refuse, the slough of the city, which is still more permeable to the surface-water than the underlying clay. A large proportion of this refuse is organic material, constantly undergoing fermentation and decomposition: the surface-water, passing through it, seizes on deleterious gases and soluble matter, and carries them to the rock below.

Our wells are sunk to the rock, or perhaps to a greater or less distance into it. The water that is obtained is mostly surfacewater, containing all the impurities it has gathered in its course. It is not uncommon to find wells within twenty feet or less of several privies, and it would be a miracle indeed if the well did not contain so much impurity as to be perceptible to both taste and smell. But as the water is cool, much more so than that supplied by the hydrants, and as habit accustoms one to its use, it is always preferred by the poor and ignorant. Beside its coolness, it has the recommendation of cheapness: it costs nothing, whereas the hydrant-water can be obtained only by purchase or stealth, and the risk of a severe penalty. Is it at all surprising that in our city the victims of cholera are most numerous in districts where the poor are supplied from wells? And not only cholera, but other diseases, prevail more extensively in these localities than where the inhabitants use hydrant water or rain-water.

The London Journal of Pharmacy has an article upon this subject, from which we cannot forbear copying freely. It says:

"The exercise of common sense in the investigation of the conditions to which water has been exposed, aided by the results of analysis, and some knowledge of physiological investigations and the laws of nature, will lead to the following conclusion with reference to wholesome water:

"First. All water that has received drainage containing animal and vegetable matter in a state of putrefaction, and

especially excrementitious matter, either is, or is liable to be, in a state unfit for use as drinking-water, and the chemist cannot determine by analysis whether the dangerous state exists or

not.

"Second. All rivers necessarily receive drainage, and they are generally contaminated with sewage and other decomposing organic matter, which may render the use of such water injurious to health.

"Third. Shallow wells situated in large towns are subject to pollution from infiltration, from leakage of sewers, and other similar causes; and, as these waters are stagnant, the organic matter present if it has not passed, is liable to assume its most dangerous conditions.

"Fourth. Spring-water, when favorably situated, is free from suspicion of containing organic impurity that could prove injurious.

"Fifth. Rain-water, if properly collected and stored, is the best and safest water to use for domestic purposes, and especially for drinking.

"Sixth. In the absence of rain-water or good spring-water, the best and most palatable water should be selected from other sources, choosing that which is most free from organic matter, and which has been least exposed to sewage contamination. In order to guard, as far as possible, against the influence of living germs, by which it is supposed that disease may be propagated, it is recommended, on the highest authority, that, when water to which a suspicion attaches is used for drinking purposes, it should be previously boiled, the heat of boiling water being destructive to the vitality of such germs. A supply sufficient for the day should be daily submitted to the boiling temperature; and this, after it has cooled, may be rendered more palatable by the addition of a little syrup of lemon, or even a few drops of sulphuric acid."

Upon this subject, the Technologist, says: "Whatever be the

nature and quality of the earthy substances held in suspension in turbid water, it becomes fit for drink in from seven to fifteen minutes, if to each litre there be added forty milligrammes of finely powdered alum, care being taken to agitate the liquid when the alum is introduced; this is about three fourths of a pound to a ton of water. If potash-alum is used, the alum is decomposed into sulphate of potassa; this is all dissolved by the water and sulphate of alumina, which, by its decomposition, purifies the water. The alumina separates in an insoluble form and carries down with it, as it precipitates, the substances which rendered the water turbid and the organic matter. The acid attacks the earthy and alkaline carbonates, and transforms them into sulphates. The water becomes slightly richer in bicarbonates and free carbonic acid, whilst all organic matter is destroyed. Seven parts of sulphate of alumina will purify as much water as ten parts of rock-alum or potash-alum; and the sulphate of alumina does not introduce any alkaline sulphate into the clarified water."

THE hygienic use of Alcohol must be determined in the same manner as is its therapeutic use; that, is by thorough provings and re-provings as exhaustive as those of any other article of the materia medica.

Fortunately for us (and as unfortunately for the provers generally), there have been, from time immemorial, plenty of provings of this substance; and plenty of records of these provings have been preserved for our use. No medicinal substance has been so frequently and persistently used in all ages as alcohol. The effects are singularly uniform upon all classes and ages, varied, of course, by temperament and climate.

Alcohol affects primarily the nervous system, and, through this, the general system. In doses not too large, it is a stimulant, and, in larger doses, narcotic. In pathology it would be be said that the first effects are, to excite the nervous system, and more especially the brain, causing it to act with more energy, quickening all the functions, and stimulating the system generally.

Concentrated alchohol is a rapid poison, producing death in a remarkably short time by its destruction of the vitality of the nervous system. After long and excessive use of alcoholic liquors, the brain has been found hardened, and resembling its consistence after its removal from the cranium and immersion in alcohol.

§ VII.-6*