The human body is continually undergoing changes, which commence with the earliest dawn of existence and end only with death. The old and worn-out materials are constantly being removed to make room for the new. Growth and development, as well as the elimination of worn-out and useless matter, continually require new supplies, which are to be derived from our food. To fulfill these demands it is necessary that the nutriment should be of the proper quality, and of sufficient variety to furnish all the constituents of the healthy body. In order that food may be of utility, like other building materials, it must undergo preparation; the crude substance must be worked up into proper condition and shape for use, in other words, it must be digested. But this does not end the process of supply, each different substance must be taken by the different bands of workmen, after due preparation in the workshop, to its appropriate locality in the structure, and there fitted into its proper place; this is assimilation. In reality it becomes a portion of the body, and is advantageous in maintaining the symmetry and usefulness of the part to which it is assigned; this constitutes the ultimate object of food, nutrition.

Eating is the process of receiving the food into the mouth, i.e., prehension; mastication and insalivation—minutely dividing and mixing it with the saliva; deglutition—conveying it to the stomach. Plenty of time should be taken at meals to thoroughly masticate the food and mix it with the saliva, which, [pg 234]being one of the natural solvents, favors its farther solution by the juices of the stomach; the healthy action of the digestive powers is favored by tranquility of mind, agreeable associations, and pleasant conversation while eating. It is proverbial of the American people that they bolt their food whole, washing it down with various fluids, thus forcing the stomach to perform not only its own duties, but also those of the teeth and salivary glands. This manner of dispatching food, which should go through the natural process above described, is not without its baleful consequences, for the Americans are called a nation of dyspeptics.

Eating slowly, masticating the food thoroughly, and drinking but moderately during meals, will allow the juices of the stomach to fulfill their proper function, and healthy digestion and nutrition will result. If the food is swallowed nearly whole, not only will a longer time be required for its solution, but frequently it will ferment and begin to decay before nutritive transformation can be effected, even when the gastric juice is undiluted with the fluids which the hurried eater imbibes during his meal.

Regularity of Meals cannot be too strongly insisted upon. The stomach, as well as other parts of the body, must have intervals of rest or its energies are soon exhausted, its functions impaired, and dyspepsia is the result. Nothing of the character of food should ever be taken except at regular meal times. Some persons are munching cakes, apples, nuts, candies, etc., at all hours, and then wonder why they have weak stomachs. They take their meals regularly, and neither eat rapidly nor too much, and yet they are troubled with indigestion. The truth is they keep their stomachs almost constantly at work, and hence tired out, which is the occasion of the annoyance and distress they experience.

Eating too much. It should always be remembered that the nutrition of our bodies does not depend upon the amount eaten, but upon the amount that is digested. Eating too much is nearly as bad as swallowing the food whole. The stomach is unable to digest all of it, and it ferments and gives rise to unpleasant results. The unnatural distention of the stomach with food causes it to press upon the neighboring [pg 235]organs, interfering with the proper performance of their functions, and, if frequently repeated, gives rise to serious disease. People more frequently eat too much than too little, and to omit a meal when the stomach is slightly deranged is frequently the best medicine. It is an excellent plan to rise from the table before the desire for food is quite satisfied.

Late Suppers. It is generally conceded that late suppers are injurious, and should never be indulged in. Persons who dine late have little need of food after their dinner, unless they are kept up until a late hour. In such cases a moderate meal may be allowed, but it should be eaten two or three hours before retiring. Those who dine in the middle of the day should have supper, but sufficiently early so that a proper length of time may elapse before going to bed, in order that active digestion may not be required during sleep. On the other hand, it is not advisable to go wholly without this meal, but the food eaten should be light, easily digestible, and moderate in quantity. Persons who indulge in hearty suppers at late hours, usually experience a poor night's rest, and wake the next morning unrefreshed, with a headache and a deranged stomach. Occasionally more serious consequences follow; gastric disorders result, apoplexy is induced; or, perhaps, the individual never wakes.

Feeding Infants. For at least six or seven months after birth, the most appropriate food for an infant is its mother's milk, which, when the parent is healthy, is rich in all the elements necessary for its growth and support. Next to the mother's milk, that of a healthy nurse should be preferred; in the absence of both, milk from a cow that has recently calved is the most natural substitute, in the proportion of one part water to two parts milk, slightly sweetened. The milk used should be from but one cow. All sorts of paps, gruels, panadas, cordials, laxatives, etc., should be strictly prohibited, for their employment as food cannot be too severely censured. Vomiting, diarrhea, colic, green stools, griping, etc., are the inevitable results of their continued use. The child should be fed at regular intervals, of about two hours, and be limited to a proper amount each time, which, during the first month, is about two ounces. From 11 P.M. to 5 A.M. the child [pg 236]should be nursed but once. As the child grows older the intervals should be lengthened, and the amount taken at a time gradually increased. The plan of gorging the infant's stomach with food every time it cries, cannot be too emphatically condemned.

After the sixth or seventh month, in addition to milk, bits of bread may be allowed, the quantity being slowly increased, thus permitting the diet to change gradually from fluid to solid food, so that, when the teeth are sufficiently developed for mastication, the child has become accustomed to various kinds of nourishment. Over-feeding, and continually dosing the child with cordial, soothing syrups, etc., are the most fruitful sources of infant mortality, and should receive the condemnation of every mother in the land.

Preparation Of Food. The production of pure blood requires that all the food selected should be rich in nutritious elements, and well cooked. To announce a standard by which all persons shall be guided in the selection and preparation of their food is impossible. Especially is this the case in a country the inhabitants of which represent almost every nation on the face of the globe. Travelers are aware that there is as much diversity in the articles of food and methods of cookery, among the various nationalities, as in the erection of their dwellings, and in their mental characteristics. In America we have a conglomeration of all these peoples; and for a native American to lay down rules of cookery for his German, French, English, Welsh, and Irish neighbors, or vice versa, is useless, for they will seldom read them, and, therefore, cannot profit by them. There are, however, certain conditions recognized by the hygienic writers of every nation. The adequate nutrition of the organic tissues demands a plentiful supply of pure blood, or the digestive apparatus will become impaired, the mental processes deranged, and the entire bony and muscular systems will lose their strength and elasticity, and be incapacitated for labor.

Different Kinds of Food Required. The different periods and circumstances of life require their appropriate food, and the welfare of mankind demands that it should supply both the inorganic and organic substances employed in the development of every tissue. The inorganic elements employed in our [pg 237]construction, of which Phosphorus, Sulphur, Soda, Iron, Lime, and Potash are the most important, are not considered as aliments, but are found in the organic kingdom, variously arranged and combined with organic materials in sufficient quantities for ordinary purposes. When, however, from any cause, a lack of any of these occurs, so that their relative normal proportions are deranged, the system suffers, and restoration to a healthy condition can only be accomplished by supplying the deficiency; this may be done by selecting the article of food richest in the element which is wanting, or by introducing it as a medicine. It must be remembered that those substances which enter into the construction of the human fabric, are not promiscuously employed by nature, but that each and every one is destined to fulfill a definite indication.

Lime enters largely into the formation of bone, either as a phosphate or a carbonate, and is required in much greater quantities in early life, while the bone is undergoing development, than afterwards. In childhood the bones are composed largely of animal matter, being pliable and easily moulded. For this reason the limbs of young children bend under the weight of their bodies, and unless care is taken they become bow-legged and distorted. Whenever there is a continued deficiency of the earthy constituents, disease of the bones ensues. Therefore, during childhood, and particularly during the period of dentition, or teething, the food should be nutritious and at the same time contain a due proportion of lime, which is preferable in the form of a phosphate. When it cannot be furnished by the food, it should be supplied artificially. Delayed, prolonged, and tedious dentition generally arises from a deficiency of lime.

With the advance of age it accumulates, and the bone becomes hard, inelastic, and capable of supporting heavy weights. Farther on, as in old age, the animal matter of bone becomes diminished, and lime takes its place, so that the bones become brittle and are easily broken. Lime exists largely in hard water, and to a greater or less extent in milk, and in nearly all foods except those of an acid character.

Phosphorus exists in various combinations in different parts of the body, particularly in the brain and nervous system. Persons who perform a large amount of mental labor require [pg 238]more phosphorus than those engaged in other pursuits. It exists largely in the hulls of wheat, in fish, and in eggs. It should enter to a considerable extent into the diet of brain workers, and the bread consumed by them should be made of unbolted flour.

Sulphur, Iron, Soda, and Potash are all necessary in the various tissues of the body, and deficiency of any one of them, for any considerable length of time, results in disease. They are all supplied, variously arranged and combined, in both animal and vegetable food; in some articles they exist to a considerable extent, in others in much smaller quantities. Sulphur exists in eggs and in the flesh of animals, and often in water. Iron exists in the yolk of eggs, in flesh, and in several vegetables. Soda is supplied in nearly all food, and largely in common salt, which is a composition of sodium and hydrochloric acid, the latter entering into the gastric juice. Potash exists, in some form or other, in sufficient quantities for health, in both vegetable and animal food.

Classes of Food. All kinds of food substances may be divided into four classes. Proteids, Fats, Amyloids, and Minerals. Proteids are composed of the four elements, carbon, hydrogen, oxygen, and nitrogen, sometimes combined with sulphur and phosphorus. In this class are included the gluten of flour; the albumen, or white of eggs; and the serum of the blood; the fibrin of the blood; syntonin, the chief constituent of muscle and flesh, and casein, one of the chief constituents of cheese, and many other similar, but less frequent substances.

Fats are composed of carbon, hydrogen, and oxygen only, and contain more hydrogen than would be required to form water if united with the oxygen which they contain. All vegetable and animal oils and fatty matters are included in this class.

Amyloids consist of substances which are also composed of carbon, oxygen, and hydrogen only; but they contain just enough hydrogen to produce water when combined with their oxygen, or two parts of hydrogen to one of oxygen. This division includes sugar, starch, dextrine, and gum. The above three classes of food-stuffs are only obtained through the activity of living organisms, vegetable or animal, and have [pg 239]been, therefore, appropriately termed by Prof. Huxley, vital food-stuffs.

The mineral food-stuffs may, as we have seen, be procured from either the living or the non-living world. They include water and various earthy, metallic, and alkaline salts.

Variety of Food Necessary. No substance can serve permanently for food except it contains a certain quantity of proteid matter in the shape of albumen, fibrin, casein, etc., and, on the other hand, any substance containing proteid matter in a shape in which it can be readily assimilated, may serve as a permanent vital food-stuff. Every substance, which is to serve as a permanent food, must contain a sufficient quantity, ready-made, of this most important and complex constituent of the body. In addition, it must also contain a sufficient quantity of the mineral ingredients which enter into the composition of the body. Its power of supporting life and maintaining the weight and composition of the body remains unaltered, whether it contains fats or amyloids or not. The secretion of urea, and, consequently, the loss of nitrogen, goes on continually, and the body, therefore, must necessarily waste unless the supply of proteid matter is constantly renewed, since this is the only class of foods that contains nitrogen in any considerable quantity. There can be no absolute necessity for any other food-stuffs but those containing the proteid and mineral elements of the body. From what has been said, it will readily be seen that whether an animal be carnivorous or herbivorous, it begins to starve as soon as its vital food-stuffs consist only of amyloids, or fats, or both. It suffers from what has been termed nitrogen starvation, and if proteid matters are withheld entirely, it soon dies. In such a case, and still more in the case of an animal which is entirely deprived of vital food, the organism, as long as it continues to live, feeds upon itself, the waste products necessarily being formed at the expense of its own body.

Although proteid matter is the essential element of food, and under certain circumstances may be sufficient of itself to support the body, it is a very uneconomical food. The white of an egg, which may be taken as a type of the proteids, contains about fifteen per cent. of nitrogen, and fifty-three per cent. of carbon; therefore, a man feeding upon this, would [pg 240]take in about three and a half times as much carbon as nitrogen. It has been proved that a healthy, adult man, taking a fair amount of exercise and maintaining his weight and body temperature, eliminates about thirteen times as much carbon as nitrogen. However, if he is to get his necessary quantity, about 4000 grains of carbon, out of albumen, he must eat 7,547 grains of that substance; but this quantity of albumen contains nearly four times as much nitrogen as he requires. In other words, it takes about four pounds of lean meat, free from fat, to furnish 4,000 grains of carbon, the quantity required, whereas one pound yields the requisite quantity of nitrogen. Thus a man restricted exclusively to a proteid diet, must take an enormous quantity of it. This would involve a large amount of unnecessary physiological labor, to comminute, dissolve, and absorb the food, and to excrete the superfluous nitrogenous matter. Unproductive labor should be avoided as much in physiological as in political economy. The universal practice of subsisting on a mixed diet, in which proteids are mixed with fats or amyloids, is therefore justifiable.

Fats contain about 80 per cent. of carbon, and amyloids about 40 per cent. We have seen that there is sufficient nitrogen in a pound of meat free from fat, to supply a healthy adult man for twenty-four hours, but that it contains only one-fourth of the quantity of carbon required. About half a pound of fat, or one pound of sugar, will supply the quantity of carbon necessary. The fat, if properly subdivided, and the sugar, by reason of its solubility, pass with great ease into the circulation, the physiological labor, consequently, being reduced to a minimum.

Several common articles of diet contain in themselves all the necessary elements. Thus, butchers' meat ordinarily contains from 30 to 50 per cent. of fat; and bread contains the proteid, gluten, and the amyloids, starch and sugar, together with minute quantities of fat. However, on account of the proportion in which these proteid and other components of the body exist in these substances, neither of them, by itself is such a physiologically economical food, as it is when combined with the other in the proportion of three to eight, or three quarters of a pound of meat to two pounds of bread a day.

[pg 241]It is evident that a variety of food is necessary for health. Animals fed exclusively upon one class, or upon a single article of diet, droop and die; and in the human family we know that the constant use of one kind of diet causes disgust, even when not very long continued. Consequently, we infer that the welfare of man demands that his food be of sufficient variety to supply his body with all of its component parts. If this is not done the appetite is deranged, and often craves the very article which is necessary to supply the deficiency. After the component parts of the organism have assimilated the nutritious elements of particular kinds of food for a certain length of time, they lose the power of effecting the necessary changes for proper nutrition, and a supply of other material is imperatively demanded. When the diet has been long restricted to proteids, consisting largely of salt meats, fresh vegetables and fruits containing the organic acids, become indispensable; otherwise, the scorbutic condition, or scurvy, is almost sure to be developed. Fresh vegetables and fruits should be eaten in considerable quantities at the proper seasons.

Value Of Animal Food. The principal animal food used in this country consists of Pork, Mutton, Beef, and Fish. Beef and mutton are rich in muscle-producing material. Although pork is extensively produced in some portions of this country, and enters largely into the diet of some classes, yet its use, except in winter, is not to be encouraged. The same amount of beef would give far greater returns in muscular power.

In addition to the meats mentioned, Wild Game furnishes palatable, nutritious, and easily-digested food. Domestic Fowls, when young, are excellent, and with the exception of geese and ducks, are easily digested. Wild Birds are considered much healthier food than those which are domesticated. All of these contain more or less of the elements which enter into the composition of the four classes of foods.

Vegetable Foods. Wheat is rich in all the elements which compose the four classes, and, when the flour is unbolted, it is one of the best articles for supplying all the elements.

Barley stands next to wheat in nourishing qualities, but is not so palatable.

[pg 242]Oats are rich in all the elements necessary for nutrition. Oatmeal is a favorite article of diet among the Scotch, and, judging from their hardy constitutions, their choice is well founded. In consequence of the large proportion of phosphorus which they contain, they are capable of furnishing a large amount of nourishment for the brain.

Rye is nutritious, but it is not so rich in tissue-forming material.

Indian Corn is an article well known and extensively used throughout the United States, and is a truly valuable one, capable of being prepared in a great variety of ways for food. It contains more carbon than wheat, and less nitrogen and phosphorus, though enough of both to be extremely valuable.

Rice is rather meagre in nutriment; it contains but little phosphorous matter, with less carbon than other cereals, and is best and most generally employed as a diet in tropical countries.

Beans and Peas are rich in nutritious matter, and furnish the manual laborer with a cheap and wholesome diet.

The Potato is the most valuable of all fresh vegetables grown in temperate climates. Its flavor is very agreeable, and it contains very important nutritive and medicinal qualities, and is eaten almost daily by nearly every family in North America. Until very recently it, with the addition of a little butter-milk or skim-milk, constituted almost the sole diet of the Irish people. The average composition of the potato is stated by Dr. Smith to be as follows: Water 75 per cent., nitrogen 2.1, starch 18.8, sugar 3.2, fat 0.2, salts 0.7. The relative values of different potatoes may be ascertained very correctly by weighing them in the hand, for the heavier the tuber the more starch it contains.

Turnip and Cabbage are 92.5 per cent. water, and, consequently, poor in nutrition, though they are very palatable. The solid portions of cabbage, however, are rich in albumen.

It is evident that the quantity necessary to maintain the system in proper condition must be greatly modified by the habits of life, the condition of the organism, the age, the sex, and the climate. The daily loss of substance which must be [pg 243]replaced by material from without, as we have seen, is very great. In addition to the loss of carbon and nitrogen, about four and a half pounds of water are removed from the system in twenty-four hours, and it is necessary that about this quantity should be introduced into the system in some form or other, however much it may be adulterated. Professor Dalton states: "From experiments performed while living on an exclusive diet of bread, fresh meat, and butter, with coffee and water for drink, we have found that the entire quantity of food required during twenty-four hours by a man in full health and taking free exercise in the open air is as follows:

That is to say, rather less than two and a half pounds of solid food, and rather over three pounds of liquid food."

Climate exerts an important influence on the quantity and quality of food required by the system. In northern latitudes the inhabitants are exposed to extreme cold and require an abundant supply of food, and especially that which contains a large amount of fat. On this account fat meat is taken in large quantities and with a relish. The quantity of food consumed by the natives of the Arctic zone is almost incredible. The Russian Admiral, Saritcheff, relates that one of the Esquimaux in his presence devoured a mass of boiled rice and butter which weighed twenty-eight pounds, at a single meal, and Dr. Hayes states that usually the daily ration of an Esquimau is from twelve to fifteen pounds of meat, one-third of which is fat, and on one occasion he saw a man eat ten pounds of walrus flesh at a single meal. The intense cold creates a constant craving for fatty articles of food, and some members of his own party were in the habit of drinking the contents of the oil-kettle with great apparent relish.

Digestibility of Food. Unless an article of diet can be digested it is of no value, no matter how rich it may be in nutriment. The quantity of food taken, will influence to a considerable extent, the time consumed in its digestion. The [pg 244]stomachs of all are not alike in this respect, and the subject of time has been a difficult one to determine. The experiments of Dr. Beaumont with the Canadian, St. Martin, who accidentally discharged the contents of a loaded gun into his stomach, creating an external opening through which the process of digestion could be observed, have furnished us with the following table, which is correct enough to show relatively, if not absolutely, the time required for the digestion of various articles:

[pg 245]

Milk is more easily digested than almost any other article of food. It is very nutritious, and, on account of the variety of the elements which it contains, it is extremely valuable an [pg 246]article of diet, especially when the digestive powers are weakened, as in fevers, or during convalescence from any acute disease. Eggs are also very nutritious and easily digested. Whipped eggs are digested and assimilated with great ease. Fish, as a rule, are more speedily digested than is the flesh of warm-blooded animals. Oysters, especially when taken raw, are very easily digested. We have known dyspeptics who were unable to digest any other kind of animal food, to subsist for a considerable period upon raw oysters. The flesh of mammalia seems to be more easily digested than that of birds. Beef, mutton, lamb, and venison are easily digested, while fat roast pork and veal are digested with difficulty. According to the foregoing table vegetables were digested in about the same time as ordinary animal food, but it should be remembered that a great part of the digestion of these is effected in the small intestine. Soups are, as a rule, very quickly digested. The time required for the digestion of bread is about the same as that required for the digestion of ordinary meats. Boiled cabbage is one of the most difficult substances to digest.

Cookery. "Cookery," says Mrs. Owen, "Is the art of turning every morsel to the best use; it is the exercise of skill, thought, and ingenuity to make every particle of food yield the utmost nourishment and pleasure, of which it is capable." We are indebted to this practical woman for many valuable suggestions in this art; and some of our recommendations are drawn from her experience.

Soups. The nutritious properties, tone, and sweetness of soup depend in the first place upon the freshness and quality of the meat; secondly on the manner in which it is boiled. Soups should be nicely and delicately seasoned, according to the taste of the consumer, by using parsley, sage, savory, thyme, sweet marjoram, sweet basil, or any of the vegetable condiments. These may be raised in the garden, or obtained at the drug stores, sifted and prepared for use. In extracting the juices of meats, in order that soups may be most nutritious, it is important that the meat be put into cold water, or that which is not so hot as to coagulate the albumen (which would prevent it from being extracted), and then, by slow heat and [pg 247]a simmering process, the most nutritious properties will be brought out.

Beef Soup may be made of any bone of the beef, by putting it into cold water, adding a little salt, and skimming it well just before it boils. If a vegetable flavor be desired, celery, carrots, onions, turnips, cabbage, or potatoes, may be added, in sufficient quantities to suit the taste.

Mutton Soup may be made from the fore-quarter, in the same manner as described above, thickened with pearl-barley or rice, and flavored to suit the taste.

Boiled Fish. Clean the fish nicely, then sprinkle flour on a cloth and wrap it around them; salt the water, and, when it boils, put in the fish; let them boil half an hour, then carefully remove them to a platter, adding egg sauce and parsley. To bake fish, prepare by cleaning, scaling, etc., and let them remain in salt water for a short time. Make a stuffing of the crumbs of light bread, and add to it a little salt, pepper, butter, and sweet herbs, and stir with a spoon. Then fill the fish with the stuffing and sew it up. Put on butter, salt, pepper, and flour, having enough water in the dish to keep it from burning, and baste often. A four pound fish will bake in fifty or sixty minutes.

Broiled Steak. Sirloin and porter-house steaks should be broiled quickly. Preserve them on ice for a day or two and their tenderness is much increased. Never broil them until the meal is ready to be served.

Boiled Meat. When meat is to be boiled for eating, put it into boiling water, by which its juices are coagulated and its richness preserved. The slower it boils, the more tender, plump, and white it will be. Meat should be removed as soon as done, or it will lose its flavor and become soggy.

Pork Steaks. The best steaks are cut off the shoulder—ham steaks being rather too dry. They should be well fried, in order to destroy the little living parasites, called TrichinÆ which sometimes infest this kind of meat. They are introduced into the stomach by eating ham, pork, or sausages made from the flesh of hogs infested by them. Thorough cooking destroys them, and those who will persist in the use of swine's flesh can afford to have it "done brown."

[pg 248]Baked Mutton. To bake mutton well, a person should have a brisk, sharp fire, and keep the meat well basted. It requires two hours to bake a leg of mutton, weighing eight pounds.

Bread. The health and happiness of a family depend, to a certain extent, on good, well-baked bread. At all events, our enjoyment would be greater if it were only better prepared. We make the following extract from an article printed by the State Board of Health, concerning the food of the people of Massachusetts: "As an example of good bread we would mention that which is always to be had at the restaurant of Parker's Hotel, in Boston. It is not better than is found on the continent of Europe on all the great lines of travel, and in common use by millions of people in Germany and France; but with us, it is a rare example of what bread may be. It is made from a mixture of flour, such as is generally sold in our markets, water, salt, and yeast—nothing else. The yeast is made from malt, potatoes, and hops. The dough is kneaded from one and a half to two hours, and is then thoroughly baked." The truth seems to be that the kneading, which in this country takes the housewife's time and muscle, in Europe is done by the help of machinery. So here, in large villages and cities, people might furnish themselves with good bread, by means of co-operative associations, even at a less cost than at present.

BEVERAGES.

Water. The importance of water in the economy of nature is obvious to all. It is the most abundant substance of which we have knowledge. It composes four-fifths of the weight of vegetables, and three-fourths of that of animals. It is essential to the continuance of organic life. Water is universally present in all of the tissues and fluids of the body. It is not only abundant in the blood and secretions, but it is also an ingredient of the solids of the body. According to the most accurate computations, water is found to constitute from two-thirds to three-fourths of the entire weight of the human body. The following table, compiled by Robin and Verdeil, shows the proportion of water per thousand parts in different solids and fluids:

[pg 249]

The Natural Drink of Man. Water constitutes the natural drink of man. No other liquid can supply its place. Its presence, however, in the body is not permanent. It is discharged from the body in different ways; by the urine, the feces, the breath, and the perspiration. In the first two, it is in a liquid form, in the others in a vaporous form. It is estimated that about forty-eight per cent. is discharged in the liquid, and fifty-two per cent. in the vaporous form; but the absolute as well as the relative amount discharged depends upon a variety of circumstances.

Water is never found perfectly pure, since it holds in solution more or less of almost every substance with, which it comes in contact. Rain falling in the country remote from habitations is the purest water that nature furnishes, for it is then only charged with the natural gases of the atmosphere. In cities it absorbs organic and gaseous impurities, as it falls through the air, and flowing over roofs of houses carries with it soot and dust. Water from melted snow is purer than rain-water, since it descends in a solid form, and is therefore incapable of absorbing gases. Rain-water is not adapted to drinking purposes, unless well filtered. All water, except that which has been distilled, contains air, and it is due to this fact, that aquatic animals can live in it; for example, put a fish in distilled water and it will soon die.

Mineral Impurities. Rain-water, which has filtered through the soil and strata of the earth, dissolves the soluble materials, and carries them down to lower levels, until they finally collect in the sea. Common well, spring, and mineral waters contain from 5 to 60 grains to the gallon; sea-water contains 2,000 grains while in some parts of the Dead Sea there are [pg 250]20,000 grams to the gallon. The principal mineral impurities of well and spring water are lime, magnesia, soda, and oxide of iron, combined with carbonic and sulphuric acids, forming carbonates, sulphates, and chloride of sodium, or common salt. The most general, however, are carbonate and sulphate of lime.

Mineral waters are usually obtained from springs which contain a considerable amount of saline matter. Those waters which abound in salts of iron are called chalybeate or ferruginous. Those containing salt are termed saline. Those in which contain sulphur are termed sulphurous. Water derives the quality of hardness from the salts of lime—chiefly the sulphates—which it contains. Hard water, being an imperfect solvent, is unsuitable for washing purposes. There are two varieties of hardness, one of which is temporary, being due to the presence of carbonic acid gas in the water which holds the salts in solution and may be removed by merely boiling the water and thus expelling the gas when the salts are deposited, while the other is permanent and can only be removed by the distillation of the water. It has been ascertained that twelve pounds of the best hard soap must be added to 10,000 gallons of water of one degree of hardness before a lather will remain and, consequently, 0.12 lb. to 100 gallons of water is a measure of one degree of hardness. Since hard water is not so useful in cooking and other domestic purposes, as soft water, causing a great waste of labor and material, it is often highly desirable to soften it, which is effected by the addition of lime in what is known as Clark's process. One ounce of quicklime should be added to 1000 gallons of water for each degree of hardness. It should be first slacked and stirred up in a few gallons and then thoroughly mixed with the entire quantity. Then it should be allowed to remain, and will become clear in about three hours, but should not be drunk for twelve hours.

The purity of drinking water is a matter of much importance. That which contains a minute quantity of lead will give rise to all the symptoms of lead poisoning, if the use of it be sufficiently prolonged. An account is given of the poisoning of the royal family of France, many of whom suffered from this cause when in exile at Claremont. The amount of [pg 251]lead was only one grain in the gallon. Care should therefore be taken to avoid drinking the water which has been contained in leaden pipes. It should always be allowed to run a few minutes before being used.

An excess of saline ingredients, which in small quantities are harmless, frequently produces marked disorders of the digestive organs. A small amount of putrescent matter habitually introduced into the system, as in the use of food, is productive of the most serious results, which can be traced to the direct action of the poison introduced. A case is recorded of a certain locality favorably situated with regard to the access of pure air, where an epidemic of fever broke out much to the astonishment of the inhabitants. Upon observation it was found that the attacks of fever were limited to those families who used water from a neighboring well. The disagreeable taste of the water which had been observed, was subsequently traced to the bursting of a sewer, which had discharged a part of its contents into the well. When the cause was removed, there was no recurrence of the evil effects.

Organic Impurities. "Water is liable to organic contamination from a multitude of causes, such as drainage from dwellings, dust, insects, the decaying of vegetable and animal matter. These impurities may be mechanically suspended or held in solution in the water. Although organic impurities, which are mechanically suspended in water, are poisonous, yet they are generally associated with animalculea, and these feed upon, and finally consume them. Good water never contains animalculÆ. They are never found in freshly fallen rain-water, remote from dwellings, but abound, to a greater or less extent in cisterns, marshes, ponds, and rivers. These little workers serve a useful purpose since they consume the dead organic matter from the water, and, having fulfilled their mission, sink to the bottom and die. Water which contains organic matter is exceedingly dangerous to health, and its use should be carefully avoided.

In low lands where the current of streams is sluggish, and shallow pools abound, the water is apt to be more or less infected with decaying vegetable substances. Many people living in such localities, and wishing to obtain water with as little [pg 252]trouble as possible, dig a hole in the ground, a few feet in depth, and allow the stagnant surface water to accumulate. This water is used for drinking and cooking. The result is that ague prevails in such localities.

Care should be taken that wells, from which the water is used for household purposes, are located at a distance from barn-yards, privies, sinks, vaults, and stagnant pools.

Purification of Water. There are various methods of purifying water. It may be accomplished by distillation, which is the most perfect method; by filtration through sand, crushed charcoal, and other porous substances, which deprives it of suspended impurities and living organisms; by boiling, which destroys the vitality of all animal and vegetable matters, drives out the gases and precipitates carbonate of lime, which composes the crust frequently seen upon the inside of tea-kettles or boilers; by the use of chemical agents, which may be employed to destroy or precipitate the deleterious substances. Alum is often used to cleanse roily water, two or three grains in solution, being sufficient for a quart. It causes the impurities to settle to the bottom, so that the clear water can be poured or dipped out for use. One or two grains of the permanganate of potassium will render wholesome a gallon of water containing animal impurities.

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