FOOTNOTES[I]Canticles, viii:6, German version.
[I]Canticles, viii:6, German version.
[I]Canticles, viii:6, German version.
BY BYRON D. HALSTED, SC. D.
The Cabbageis a native of Europe, and grows wild along the sea coasts of England. The wild plant lives for two years, has fleshy leaves, and is so different from the cabbages of the garden as not to be recognized as their parent. Under cultivation this one species of plant (Brassica oleracea[1]) has produced the Savoy, Brussels sprouts, cauliflower, borecole,[2]etc. A more wonderful plant and a more useful one is seldom found in the whole range of the vegetable kingdom. The Romans did much to extend the culture of the cabbage. In Scotland it was not generally known until the time of Cromwell. Much improvement has been made in American sorts of cabbages within the past fifty years. In the wild state the cabbage has a hard, woody stalk, but the fine specimens in market have only a small stem, bearing a large, compact head, of closely folded leaves.
The first essential in the successful growing of cabbage is the right kind of soil. It should be a sandy loam, with a gravelly, and not a clayey subsoil. Soil that is naturally wet must be thoroughly underdrained before being devoted to cabbage growing. The importance of an abundance of well rotted manure can not be too fully impressed upon the mind of any person contemplating the production of excellent cabbages. Much that may be here said concerning the preparation of the soil for growing cabbages applies with equal force to the other vegetables treated in this article. Earliness is one of the leading points to be gained in raising most garden crops. It is the man with the first load of cabbages that gets the best price in the market. There is a great deal of stress to be placed upon the proper selection of seed, but seed is not all. The young plants of the earliest sorts must be fed, and they require this food at an early stage in their growth, when chemical changes are only slowly going on in the soil. In other words, early crops need a far larger amount of manure for their satisfactorygrowth than crops started in midsummer, when the soil is rapidly yielding up its food elements. Early crops need to grow in cool spring weather, and therefore should be abundantly supplied with food in an available form. Mr. Gregory says in his excellent pamphlet on “How to Grow Cabbages,” “If the farmer desires to make the utmost use of his manure for that season, it will be best to put most of it into the hill, particularly if his supply runs rather short; but if he desires to leave his land in good condition for next year’s crop, he had better use part of it broadcast. My own practice is to use all my rich compost broadcast, and depend on guano, phosphates, or hen manure in the hill.” This view of heavy manuring is confirmed by Mr. Henderson, in his “Farm and Garden Topics,” when he says: “For the early cabbage crop it should always be spread on broadcast, and in quantity not less than one hundred cart loads or seventy-five tons to the acre.… After plowing in the manure, and before the ground is harrowed, our best growers in the vicinity of New York sow from four to five hundred pounds of guano, or bone dust, and then harrow it deeply in.” The best sorts of cabbages for the early crop are: The Jersey Wakefield, which has a head of medium size, close, and of a deep green color; Early York, smaller, but quite early; Early Winningstadt, later, but an excellent sort. Among the best late kinds may be named: Large Flat Dutch, American Drumhead, Drumhead Savoy, and the Red Dutch. The last mentioned is largely used in pickling.
The young plants are obtained from seeds in various ways, determined by the numbers desired. When large quantities are needed for the early crop, the seed is sown in a hot-bed or green-house, about February 1st, for the latitude of New York City, and transplanted into other heated beds near March 1st. In this way fine plants may be obtained by the first of April. Many of the large cabbage growers prepare the soil, mark it in rows, and drop the seed in the hills where the plants are to grow. In this way much labor is saved, and there is the advantage of having several plants in each hill, to guard against losses from cut-worms. Cabbages quickly respond to good culture, and repay in large measure for every stirring of the soil, either with the hoe or the horse cultivator.
The most troublesome insect enemy is probably the Cabbage-worm, which in some localities has destroyed the whole crop. The mature insect deposits its eggs upon the under side of the cabbage leaves. These eggs soon hatch, and the green caterpillars begin their destructive work. No poisonous substances can be applied without endangering the lives of those who may afterward eat the cabbage. Hot water (160 degrees) has proved effective in killing the worms, while not doing injury to the plants. Flea-beetles have done some damage, as also the Cabbage-bug. After the crop is grown the cabbages may be kept by burying them in trenches, heads down. Three facts need to be kept in mind: Repeated freezing and thawing cause rot; excessive moisture also induces decay; and a dry air withers the head and destroys the flavor. About a foot of earth is usually a sufficient covering.
Cabbage in the many forms it is presented upon the table is a most wholesome and agreeable article of food. The farmer’s garden is not complete without a full crop of cabbages. Any heads that are not needed for the family table can be fed with profit to the farm live stock. Poultry in particular, need some green food daily through the winter season, and a cabbage now and then satisfies this natural craving.
Turnips.—The garden turnips belong to the same genus (Brassica) with the cabbages, and are therefore closely related to them. The turnip is supposed to be a native of England and other parts of Europe. It is not known when this plant was first introduced into cultivation, and its wild state is unknown. At the present time it forms one of the prominent crops in all countries adapted to its growth.
The remarks made under the subject of cabbages concerning the free use of manure need not be repeated here. Turnips grow freely upon a rich and mellow soil, kept clean of all weeds. They do not require as fertile a soil as cabbages, and when the earth is very rich, there is sometimes an excessive growth of tops, without a corresponding development of the roots. It is not necessary to say that cabbages are grown for their many thick leaves, while turnips are raised for their roots. Plants as a whole have many places for the storing up of nourishment. Sometimes it is in the stems, as in the potato; in other cases the leaves or roots serve as a store-house of accumulated substance. The plant makes these deposits, to be drawn upon at some future time, either for further growth of the same plant or for the early development of another. The root crops, for example, are naturally plants of two year’s duration. The first season is spent in gathering and storing up substance in a large root. During the following year the starch, sugar, oil, etc., is withdrawn and used in the production of a flower-stalk, upon which the crop of seeds is finally borne, and after this the plant dies.
Turnips are mainly grown as a second crop, following early potatoes, etc. The soil should be made fine and rich before the seed is sown. Rutabagas may be sown from the 15th of June until the 15th of July. Yellow Stone, Aberdeen, White Cowhorn and Strap-leaved Red-top are sown in the order named, and from July 15th to the 1st or 10th of September. The seed is sown in drills, wide enough apart to admit of horse cultivation. The thinning of the plants in the row is of great importance. This work is best done with a hoe, the workman chopping out the turnips and leaving the plants about four to six inches apart in the row. In garden culture the rows need not be so far apart. It is very essential to keep the weeds down and the soil frequently stirred. The harvesting is simple. When growth is completed the roots are pulled, then the tops cut off and the turnips placed in root cellars or pits.
Turnips have an important place in a carefully planned system of farming. The root crop is a means of securing a large amount of most wholesome food for live stock, and at the same time it cleans the soil from weeds and prepares it for the growth of succeeding crops.
The leading insect enemy of young turnip plants is the Turnip-fly. If the seedlings can be protected until they get a good start in life there is no further trouble. Equal parts of wood ashes and land plaster scattered over the young turnip leaves is a good remedy. Air-slaked lime is also employed in the same manner.
The Carrot.—The wild carrot,Daucus Carota,[3]is a native of Europe and has become naturalized in this country to such an extent as to be ranked among the worst of weeds. The cultivated carrot was introduced into England by the Dutch, in the reign of Queen Elizabeth (last half of the sixteenth century), and has since been much improved and quite generally grown. In its native or wild state the root is small, woody, and of very little value as an article of food. All of our so-called “root plants” in the wild state store up only sufficient food in the root to meet the wants of the plant the coming season. This tendency to accumulate has been developed under cultivation, and an excess is stored up, which is appropriated by man. The plant has enjoyed more favorable conditions for growth and been relieved in great part of the struggle for existence that is constantly going on among wild plants. All cultivated plants are living unnatural lives, being favored in various ways, and when they are left to shift for themselves either die or drift back, generation after generation, to the old original form from which the ancestors were forced to depart. No plant is a better illustration of this fact than the carrot. If left for only a few years, the fleshy rooted plants of the garden degenerate into the coarse, woody-rooted weeds of the pasture or hedge-row. We can not pass this point without endeavoring to enforce the importance of keeping up all the most favorable conditions of growth for garden vegetables, and carefullyselecting seed of plants that show the least tendency to degenerate.
The plot for growing carrots should be nearly level, otherwise heavy rains may wash the seeds and young plants out of place. The soil should be deep, rich and mellow. Carrots are no exception to the rule that root crops flourish under high culture. When the barnyard fails to supply sufficient manure, it is well to use guano, superphosphates, and other quick acting fertilizers. If the soil is heavy, it is best to sow the seed in ridges made by a plow, thus enabling a horse-weeder to pass between the rows and not injure the young plants coming through the surface. Use seed not over one year old, and it is well to sow some radish seed with it, to come up first and show the rows, thus aiding in the early cultivation of the soil. It is of the greatest importance to keep the weeds down until the carrots get a good start. About six weeks after sowing, that is, the middle of July, thin the plants, leaving them four or five inches apart in the row. The carrots are dug and stored like most root crops. If grown in large quantities, most of the labor of getting the roots out of the soil is performed by horses. Carrots keep well in long piles, six feet wide at the bottom, and of any length. Ventilating holes need to be left at frequent intervals along the ridge of the covered heap. There are several varieties of carrots, some of them being earlier than others, while the size and general shape varies greatly. The Long Orange, Short Horn, Early Horn and White Belgian are among the leading sorts. Market gardeners are now favoring the shorter sorts, the endeavor being to get them turnip-shaped, and thus save much labor in digging the roots.
Beets.—The speciesBeta vulgaris,[4]the parent of our common beets, is a native of Egypt, and grows wild along the Mediterranean Sea at the present day. The name is from the Celtic wordBett, meaningred, the prevailing color of most beets. This garden vegetable has been generally grown for six hundred years, and during that time has undergone many important changes. Long ago the beet arrived at a state of perfection beyond which it is not easy to pass. The Mangold-Wurzel[5]and Sugar Beets are derived from another species. These are grown very extensively in Europe and are worthy of far more attention by American farmers. The Swiss Chard is another species of the genusBeta, largely grown in some countries for the leaves, which only are used. They are stripped off and used like spinach. The soil best adapted to the growing of beets is a rich, sandy loam, rather light than otherwise. It should be thoroughly pulverized by deep plowing, harrowing, etc., until a fine, mellow bed is prepared for the seeds. The seeds are sown in rows, and the soil should be pressed firmly upon them. For early beets the sowing may be done so soon as the ground can be worked. The late sorts may be sown in July. As soon as the plants are above ground a push-hoe should be passed close to the rows. A few days later the beets need to be thinned to five or six inches in the row. The removed plants make excellent greens. The remaining work until harvest time is keeping the soil free from weeds and loose by frequent hoeing. The rake is better than the hoe, if it is used frequently and no weeds get large. Beets should be harvested before frosts injure them. Handle carefully and store in a place where the temperature is uniformly a few degrees above freezing.
The Egyptian is among the best early sorts; it has a dark blood color, and much resembles a flat turnip in shape. The Long, Smooth, Blood Beet is considered as ranking first for general family and market uses.
The Mangold-Wurzels are coarse beets of large size, grown as a field crop for live stock. The White Sugar is a Mangold, free from much of the red coloring matter of the red sorts. These larger varieties of beets are very extensively grown in Europe for the manufacture of sugar, and it would add to our agricultural wealth if they were more frequently a part of a well planned system of rotation of crops in America. It may not pay for us to make beet sugar, but the use of the roots as a wholesome winter food for stock is profitable.
Onions.—The onion (Allium cepa[6]) has been cultivated from early times, and its native country is unknown. As it is mentioned in sacred writings it is supposed that its home is in the far East. Onions thrive best on old ground, especially if it is a light, sandy loam. The onion field should be nearly level, clear of weeds, and liberally supplied with the best well-rotted manure; guano and superphosphates are excellent for onions. Deep plowing is not necessary. The amount of seed to be used depends upon the kind of onions desired. If they are to be pulled for early market, more seed is required than when they are to attain their full growth.
There are many varieties of onions grown from seeds. The Yellow Danvers, White Portugal and Weathersfield Red are well known sorts, representing the three prevailing colors. Onions are largely grown from sets, that is, bulbs that have ripened while quite small, and when set out grow and form large onions. The small size and early maturity are due to sowing the seed thick. From thirty to forty seeds are sown to each inch of the row. The sets are mature when the leaves begin to wither, and are then removed and dried. In planting the sets they are placed in rows about four inches apart.
The “Potato Onion” or “English Multiplier” is propagated by offsets. An onion of this class, if planted in the spring, will produce a cluster of small ones around it. These small onions will grow into large ones the next season. There are several sorts of onions that bear clusters of small bulbs upon the tops of the flower stalks, in place of seed pods. The “Tree,” “Top,” and “Egyptian” onions are of this class. These bulblets, when planted, produce large bulbs, and these latter, when set out the following season, throw up stalks bearing bulblets.
Onions are ready for harvesting as soon as the leaves droop and become dry. The bulbs should be well cured and placed in a dry, cool, storage room. The crop is sometimes badly injured by smut, especially when onions have been grown upon the same soil for many years. The onion maggot causes some destruction. Guano and unleached ashes, when scattered over the bed, have both proved of value.
The above is only a brief consideration of five of the leading garden vegetables. The first four, namely: Cabbages, turnips, carrots and beets, are to a great extent farm crops, well suited for live stock. The composition of these is as follows:
The turnips contain the least dry substance, and the cabbages are far the richest in albuminoids. The carrot leads in starch, sugar, etc., followed closely by the beets. There is very little poetry in any of the five vegetables here briefly described, though they may enter into the daily food of those who think of lofty things and write in the most elegant style. They are the humble, unobtrusive toilers in the gardens of the world.
There are two laws underlying the preparation of all vegetables for the table; the first is, cook until tender; the second is, do not cook until mushy and the juice extracted. By overlooking the first you are left with a rank, tough, indigestible dish; by overlooking the second with one watery, and—worst of all culinary adjectives—juiceless. A time-table regulating the exact number of minutes which each vegetable shall be cooked can not be perfectly exact. Not rules, but judgmentmust decide the limit of time. However a table of approximations may be of service to amateur cooks whose experience has not yet taught them that essential of successful cookery.
Cabbage.—When young, requires an hour; winter cabbage, double that time.
Turnips.—When young, three quarters of an hour; winter turnips, two hours.
Carrots.—When young, three quarters of an hour; winter carrots, two hours.
Beets.—When young, three quarters of an hour; winter beets, four hours.
Onions.—When young, one hour; winter onions, two hours.
The temperature at which vegetables should be cooked is a point of great importance. A little reflection should easily settle the question, however. When young vegetables are tender, the juices are easily withdrawn, continued stewing or soaking extracts all the flavor and strength; when old they become tough, and only long stewing will make them tender and bring out the juices. By putting young vegetables into cold water we extract the juice before they begin to cook, and by the time they become tender they are tasteless; but by putting winter vegetables into cold water they are gradually softened, and by the time they are cooked tender the juice is fully developed; hence the reason for the rule which cooks have formulated: Put all young, green vegetables into salted boiling water; all dried and winter vegetables into cold water.
Add to your regard for these first principles a nice skill in draining all the water from your cabbage, turnips, carrots, beets and onions, and that most delicate of all cookery arts—the art of seasoning—and you can not fail of toothsome entrées[1]and salads.
Cabbage Salad or Slaw.—Remove from a firm, fresh cabbage the outer leaves and slice fine. The simplest dressing is of sugar, salt and vinegar. Mayonnaise[2]dressing may be prepared by taking the beaten yolks of six eggs and into them beating, drop by drop, two tablespoonfuls of salad oil; now alternate with every few drops of two tablespoonfuls of salad oil, small quantities of vinegar until two tablespoonfuls of vinegar have been used. Beat into this mixture, which should be very smooth, one saltspoonful of salt and half as much cayenne pepper, set in a cold place until wanted. A cooked mayonnaise dressing is made by adding to each tablespoonful of boiling vinegar, the beaten yolk of an egg, and cooking until stiff. Remove the mixture and stir in an ounce of butter. When cool, season it with salt, pepper and mustard; then add sweet cream until it is of the desired consistency.
Hot Slawis prepared by stewing chopped cabbage until tender, and then adding a dressing of vinegar, butter, salt and pepper.
Pickled Cabbage.—Chop, not too fine, a fresh cabbage, and season it with white mustard seed, salt and pepper. Now pack this firmly into a jar and add cold vinegar. Cloves should be sprinkled over the top to prevent mould. Or, pack a layer of chopped cabbage alternately with a layer of chopped onions, and having salted, allow it to stand for about twenty-four hours. A dressing of one pint of vinegar, one cup of sugar, and one teaspoonful each of ground mustard, black pepper, cinnamon, turmeric, mace, allspice, and celery seed is made for each head of cabbage and half dozen of onions, by scalding the vinegar and adding sugar and spices. Into this dressing pour the cabbage and onions. Allow them to simmer for half an hour, then put into jars.
Boiled Cabbage.—Quarter a cabbage from which the outer leaves have been removed, and which has been examined carefully for insects and slugs. Boil until tender. Drain well, being careful to press out the water. Boiled cabbage may be chopped, and a tablespoonful of butter, pepper and salt stirred in, or it may be served with white sauce or drawn butter. White sauce is made by cooking together one ounce of flour and two ounces of butter, and, after adding a pint of milk allowing the mixture to simmer slowly. Season with salt and pepper. Drawn butter differs from white sauce only in having water or broth in place of the milk. Cabbage may be boiled in water taken from the pot in which corned beef or pork is being cooked. This seasons it nicely.
Stewed Cabbage.—Chop cabbage fine and stew until tender. When “done” add sweet milk sufficient for a dressing and allow it to cook for ten minutes. Season with salt and pepper. Marion Harland gives this recipe for a stewed “stuffed cabbage:” “Choose for this purpose a large, firm cabbage. When perfectly cold bind a broad tape about it, or a strip of muslin, that it may not fall apart when the stalk is taken out. Remove this with a thin, sharp knife, leaving a hole about as deep as your middle finger. Without widening the mouth of the aperture excavate the center. Chop the bits you have taken out very small; mix with some cold boiled pork or ham, or cooked sausage-meat, a very little onion, pepper, salt, a pinch of thyme, and some bread crumbs. Fill the cavity with this, bind a wide strip of muslin over the hole in the top, and lay the cabbage in a large sauce-pan with a pint of ‘hot liquor’ from boiled beef or ham. Stew gently until very tender. Take out the cabbage, unbind carefully, and lay in a dish. Keep hot while you add to the gravy, when you have strained it, pepper, a piece of butter rolled in flour, and two or three tablespoonfuls of rich milk or cream. Boil up and pour over the cabbage.”
Baked Cabbage.—The cold boiled cabbage left over from dinner is very nice baked. Chop it fine and add a dressing made of beaten eggs and milk and seasoned with salt and pepper. Put it into a buttered baking dish, and having strewn the top with bread crumbs or rolled crackers, bake it brown.
Fried Cabbage.—Another excellent dish to be prepared from cold boiled cabbage is fried cabbage. Chop the cabbage fine and stir in a little melted butter, two beaten eggs, a little cream, pepper and salt, and cook until slightly brown.
Boiled Turnips.—Boil until tender and drain dry. After mashing them smooth, being careful to rub away all hard lumps, stir in a tablespoonful of butter and season with salt and pepper. If it is preferred to cut them in slices, they are nice served with white sauce or drawn butter as a dressing. A little vinegar added to the dressing is by many considered an improvement. Young turnips are nice served whole with either of these sauces.
Stewed Turnips.—An excellent way of warming over boiled turnips is to add sufficient milk to them to stew thoroughly, and then to season with pepper and salt.
Baked Turnips.—Cold boiled or sliced turnips may be “done over” by putting them into a baking-pan, covering with bread crumbs, moistening with milk, and then baking in the oven. Freshly boiled turnips, sliced thin, may be cooked in the same way.
Boiled Carrots.—If carrots are small and young they may be boiled whole, but if they are large they should be split into two or three pieces; when cooked they may be served with butter, salt and pepper, or with white sauce, like sliced boiled turnips.
Mashed Carrots.—Boiled carrots are very nice mashed with a large spoonful of butter, a little cream, and seasoning of pepper and salt worked into them. Serve as you would mashed potatoes.
Fried Carrots.—Cold boiled carrots, or those which have been parboiled, may be sliced and fried brown in butter. They must be seasoned, of course, with pepper and salt.
Stewed Carrots.—Parboil carrots for three quarters of an hour. Put them into a stew-pan and pour on them a teacupful of broth with seasoning of pepper, salt and butter, and stew until they are tender. A little cream and a lump of butter may be added and the whole allowed to boil up.
Boiled Beets.—In preparing beets for the kettle they should be washed, but not cut. When done, rub off the skin and slice. Butter, pepper and salt should be added for seasoning. If youlike a dressing of vinegar put a tablespoonful of butter into half a cup of vinegar, add pepper and salt, and boil before turning upon the beets.
Baked Beets.—Slice your beets and place in a baking pan with butter, pepper and salt. Allow about twenty minutes longer for baking than boiling. This method preserves much of the juice of the vegetable which is lost in boiling.
Stewed Beets.—Parboil your beets until nearly done, rub off the skin and slice. Into your stew-pan pour enough milk to cover the beets, add a little butter, salt and pepper, and simmer slowly until they are done.
Boiled Onions.—Onions may be laid in cold water half an hour before cooking. Boil them in two waters until tender. When cooked, drain carefully and serve with butter, salt and pepper. Boiled onions are nice with a dressing of drawn butter.
Baked Onions.—Choose large onions for baking, and after peeling boil for an hour. Drain them thoroughly and about each wrap a piece of buttered tissue paper, bake them until they are quite tender, then remove the paper and brown in the oven, basting with butter. Serve them with drawn butter.
Stewed Onions.—Onions which have been parboiled may be stewed in milk sufficient to cover. When done, a dressing of hot cream and butter, seasoned with salt and pepper, may be poured over them; or they may be chopped fine, and the cream, butter and seasonings be stirred in.
Fried Onions.—Slice into small strips and fry in butter, taking care to brown them evenly. Season with salt and pepper. Onions sliced thin and fried in hot fat are calledSaratoga onions.
In the science of material things, mechanics takes account of forces that act on masses from without; physics, of those that act from within, or which, in some way, modify the condition of the bodies themselves. Both branches were, till recently, included in the vaguely comprehensive term “Natural Philosophy,” and the partial separation observed in modern treatises and text-books gives a little more distinctness to the facts presented. Under the former the earth is contemplated as a planet, obedient to the universal law of gravitation, and moving regularly in its orbit. The mechanism of the system is complete; the measure and adjustment of all the parts perfect.
As a physical science, considers the earth apart from the solar system with which it is connected, and takes account of its materials and structure, and the forces that unite them. Its position in the group is about midway between mechanics and chemistry, being closely allied to other natural sciences, while its phenomena are occasionally varied by both mechanical and chemical agents.
Treats of the earth’s exterior physical features; of its form—an oblate spheroid—of its surface, oceans, continents, seas, lakes and rivers, hills, mountains, valleys and plains; of soils made from previously existing organic or inorganic substances, the detritus of rocks containing various minerals and small particles of decomposed vegetable matter. The materials of this outer covering of the earth are from many different sources, and variously constituted. From the finest grains of sand, clay, and loam, to pebbles, boulders, and fragments of enormous dimensions, they are mingled apparently without any fixed order or proportions; sometimes but slightly covering the solid rock, at others piling it up in ridges and hills of considerable height. In this surface formation are included ancient sea-beaches, lake and river terraces, deltas, deposits of sand and clay, with vast beds of marls, peat and calcareous tufa,[1]all the progressive accumulations since the present order of things began. In some of these deposits, more recent than the Drift[2]period, fossils are abundant and very full of interest. In New Zealand the bones of a bird[3]were found which exceed in bulk those of the largest horse, and are now in the museum of the College of Surgeons, London. The bird when alive was eleven or twelve feet high.
Less than a century ago what might have been a fossil elephant was found imbedded in ice on the coast of Siberia, and in such a perfect state of preservation that the people fed their dogs on its flesh. The animal was well covered with hair, and adapted to a cool climate, a representative of an extinct race. How it was imbedded, or how long it had been preserved in that condition, no one knows.
In Great Britain are found fossils of the rhinoceros and hippopotamus, of elephants, tigers, hyenas and giant elks, all of which are extinct species. The United States is especially prolific in the remains of huge mammals. The mastodon and megatherium were doubtless indigenous to this country. The latter had a thigh bone three times as large as the largest elephant, and the cavity through which it passed, indicates a spinal cord an inch in diameter. These largest skeletons were found in Georgia and South Carolina. Those of the mastodon are numerous, and found in many different places. Physiographic geology is a study intensely interesting, and of great practical importance, as it bears directly on many of the industries of life; but this general notice is sufficient.
The ultimate particles of material bodies, of which we know but little, exert such force or influence on each other as to decide the character of the mass; even if the atoms are identically the same in substance they may come together in a way to secure different results. The bulk of the solid part of the earth is rock, but all rock is not the same. We find several species of granite, of limestone, and sandstone, a long list. But the whole may be divided into two classes, stratified and unstratified. Whatever the two classes seem to have in common, they are not of the same origin. The first occur in layers or strata, others are crystalline and massive. The loose materials, such as sand, clay and gravel, that have accumulated at the bottom of the pond or lake, are found arranged in beds or parallel layers. The streams carry the materials from the highlands, and they are at length deposited in the basin, and when hardened become stratified rocks. As this process is still going on, and recently formed strata are found approaching the consistency of stone, it is but reasonable to conclude that all rocks of this class, being formed in like manner under the water, are of aqueous origin. They are further classed according to certain peculiarities, either of material or formation.
Gneiss, abundant in all parts of New England, is a kind of stratified granite, of about the same materials, but splits readily into slabs that are used both for building purposes and flagging stones.
Mica slateresembles gneiss, has the same minerals, but more mica, and is of a more slaty structure, and the glistening particles of mica abound in it.
There are several other kinds of slate, named from the minerals that predominate in them, or the purposes for which they are mostly used. Roofing slate of excellent quality is extensively quarried in Maine, Vermont and Massachusetts.
Quartzrock consists mainly of quartz, but often has more or less mica.Sandstoneis of kindred formation, the principal part of which is quartz, reduced to sand, and the grains more or less firmly united. In both the colors are various.
Conglomerateconsists of water-worn pebbles of variouskinds and sizes cemented together, and sometimes making a strong, compact rock.
The limestone formationsare extensive in nearly all countries. In their structure some are very compact and break with a smooth surface. Those capable of a fine polish are called marble, the more common uses of which are well known. The purest crystalline limestone is used in sculpture; the best quality being obtained from Carrara, Italy, and that called Parian from the island Paros.
Chalk, a useful formation, is a carbonate of lime. In some caves the dropping of calcareous water forms stalactites, which hang from the roof like immense icicles, and are often extended till they meet the accumulations below, called stalagmites, and form beautiful columns. Of the more than seven hundred crystals from this source alone, and of the many other varieties of minerals having much in common, and yet enough that is peculiar to distinguish them, no mention can be made. A careful reader and close observer will gather from familiar objects a fund of information of great value.
The parallel strata mentioned are not always horizontal, but sometimes nearly, if not quite perpendicular. Occasionally a ledge broken quite through separates, and the rock on one side of the fissure is either elevated or depressed, making what is called a fault.
The fissures crossing a bed of rock are often filled with a mineral entirely different from the rock itself. In some cases where the vein is small the foreign substance may have come in from above or laterally, deposited from water as in the case of stalactites. The larger fissures were evidently filled with the melted material thrust up from beneath.
The unstratified rocks are in masses, without fossils of animals or plants, and of igneous origin. Some of this class were probably formed later, and by the melting of secondary rocks, but most of them by the gradual cooling of the central mass containing the melted minerals embodied in them.
Treats of the forces that move things on or beneath the earth’s surface. The Drift shows not a little confusion. Things are evidently in an abnormal condition, and strangely mixed. Some of the disturbing causes are obvious. Currents of the atmosphere and ocean have done much, but are not sufficient to account for all the phenomena. Boulders brought from ledges north of the great western lakes, are found scattered over all the western states, some much battered on the passage, others bearing only marks of long exposure to the elements. Deep furrows have been plowed in the rocks and hill tops over which they passed, at an elevation of thousands of feet above the level of the sea. Currents of water could never have lifted such huge masses from the lower to higher levels, or transported them any such distances. Icebergs or glaciers have evidently moved over the whole Drift region with fragments of rocks and pebbles frozen into their lower surface, that, like huge rasps, both cut away and polished the hardest rocks, at the same time bearing forward the boulders and whatever else chanced to be held in their cold embrace. There are other footprints of many and very great changes that have been wrought. Though many persons have erroneous impressions of the inequalities on the earth’s surface, the height of the loftiest mountains being but little when compared with the earth’s diameter, yet there is evidence that the normal condition has not been preserved. Large districts have, even within the historic period, been lifted far above their former level, and others sunk as much below. New islands have appeared in the midst of the sea, while others have sunk out of sight. Multitudes now live on what was once the bed of the sea, “in which were things innumerable, great and small beasts;” and ships sail over territory once covered with the habitations of living men. Rocks of immense thickness have been broken and the parts lifted into a vertical position, and many such great changes have taken place. What wrought them? It is safe to say that at least two forces have been operating, the one more gradual than the other. The cooling of the internal mass must cause contraction, which, in a globe of such dimensions, would be sufficient to break the strongest rocks constituting its shell. This force, when properly directed, might lift the rocks, and even throw them back on other strata of more recent formation. Then the expansive force of the gases within, when raised to their highest tension, is enough to cause earthquakes, and pour through the partially opened craters, or where the barriers are made less secure, floods of lava that are in time changed into rocks of that peculiar class. The vent will be found where the crust above the struggling giant is weakest, whether that be on the mountain top where the rocks had been shoved up into a vertical position, or at the bottom of the sea.
The dynamics of geology suggest problems of no ordinary interest, but our narrow limits forbid even a statement of them.
Is that branch of geology that treats of mineral substances, and teaches how to distinguish and classify them according to their properties. This is a wide field for investigation, and so fruitful that the temptation to linger in it is strong. Mining and work with the products of the mines engage the industry of so many that it would be especially pleasant to study with them a subject of such general interest. We relinquish that privilege, in order to state two or three things that seem thoroughly established by what is found written in the book of nature, and are in perfect accord with God’s later scriptures, the Bible, when rightly interpreted.
1. The first fact is the great age of the earth. Processes are plainly indicated that must have required not only thousands, but millions of years for our planet, before man, made in the image of God, entered it as the theater of his responsible activities. The facts of the carboniferous[4]period alone discredit, and utterly overthrow the theory which limits the days of creation to six of twenty-four hours each. The Bible gives the order of the successive creations, but does not fix the age of the things created. The word translated day often means anageor an indefinite number of years, as is seen by referring to the places where it is found. Give it this well established meaning in the first chapter of Genesis, and all is plain. There was time for millions of races of inferior creatures to live and die before the divine plans and works were consummated, and the earth became a suitable abode for the human race.
2. The second great fact is that all things were made on a plan, and in some connection. There are no isolated objects or superfluous parts in the physical world. The number may be countless, and the forms given them reveal an endless variety, but each has its connections, and all the parts are necessary to a perfect whole.
3. Another lesson is learned from the mute witnesses, which is that, while a long succession of races of animals, for which the earth, in its different stages of progress was a fit abode, existed, each higher in rank than its predecessor, the several races had distinctive characteristics, as theradiates,mollusks,articulates, andvertebrates. A lower species, when its purpose is served, becomes extinct, and is succeeded by a higher.
By analyzing compound and compounding simple substances, discovers their elementary properties, the forces that are resident in matter, and the laws that govern them. It demonstrates by experiments the affinity of ultimate particles, and of gases of unlike kinds for each other, an affinity which produces homogeneous compounds, often very unlike the elements that unite in forming them. The chemist has much to do with physical objects, but in handling them his appropriate business is to consider the changes produced by chemical attraction in all bodies, whether solid, liquid, or gaseous.
Is an ancient science, suitable for schools of all grades, and not for primary and intermediate departments alone. The child can treasure many of the facts that, if held in the memory, will be of use to him as he advances in years and knowledge, but his geography will benefit him little unless it is studied when his faculties are more mature. One who despises this study as beneath him, knows nothing yet of the important science as he ought.
Has many things in common with both astronomy and geology, as it discusses the physical condition of the earth and its relations as a member of the solar system; describes its great natural divisions of land and water; and takes account of dynamic forces, such as aerial and oceanic currents, that are constantly causing important changes. The whole exterior structure of the earth, the phenomena of rain and dew, fog, frost, and snow, are geographical questions, to be discussed with special reference to the general laws or principles involved. It shows unity in the midst of diversity, and constancy of phenomena in the midst of apparent changes.
Treats of the form and size of the earth, of the construction of globes to represent it; determines the latitude and longitude of places on its surface, and all geographical problems pertaining to numbers, distances, and magnitudes.
Describes, in a general way, the countries and nations of men as they are politically divided, defines their boundaries, and to some extent characterizes their social and civil institutions. A great advance has been made in this branch during the present century. People respecting whom little was known, have come into the family of nations. The maps have been changed, and generally in a way that indicates the rapid progress of civilization. Asia has been so thoroughly explored that our general knowledge of the country may be regarded as nearly complete. No greatterra incognitaremains in that quarter, though fuller and more precise knowledge respecting the people in some parts is yet much to be desired. The interior of Africa is still but partially known, though the work of discovery has been pushed forward with considerable enterprise, and a host of explorers have struggled to penetrate the mystery that enveloped, for ages, that great division of the globe. The Upper Nile country has been explored far beyond the region assigned on the maps to the “Mountains of the Moon,” and all know the intense anxiety that is to-day felt for the safety of General Gordon and his little garrison, still shut up in Khartoum.
The study of geography, rightly pursued, is remunerative, full of inspiration, and as intensely interesting as any in the whole circle of physical sciences.
Is scientific discourse about life and vital forces. We give it a high position in the circle, since vitality is superior to either chemical or mechanical laws, suspending or modifying them for the production of organized structures of plants and animals. Evenvegetable biologyconfronts us with that mystery of mysteries, life, which is quite inexplicable. We can only say it is a peculiar, indefinable something, necessary to the existence of such organisms, and without which they soon sink in ruinous decay.
The living germ is the determining power that shapes the organic body, and every germ will have its own body. Under no possible culture can the acorn develop into an animal. It will produce an oak, a tree of its own species, and nothing else can grow from it. So also of the animal germ. The form or kind is as determinate while the embryo is yet in the egg, as it will ever be. The life once begun in everything that lives and grows, there is a power that takes hold of the elements nature has in store for it, and, by a most wonderful transformation, works them up into its own body; and this power of assimilation must forever distinguish it from all lifeless inorganic matter.
The mystery deepens when we notice that living things exist in generations. The plant has seed in itself for the production of another plant. It has life in itself, and power to vitalize its successors. The products of the field and the forest grow and mature, then wither and decay; but they have successors of the same kind.
So human beings exist in successive generations. One generation passeth away, and another cometh, and so the race lives on. While alike in their power of assimilation and reproduction, there is a wide difference between the vegetable and the animal. They have not the same organs, and do not subsist on the same food. The plant is constantly consuming carbonic acid, and giving out oxygen, while animals consume the oxygen, and restore to the atmosphere carbonic acid. The difference of their physical structure, and their different relations to inorganic matter, suggest a wide difference in the “bios” or life, that animates them. Just what that difference is, no one can tell. It is a question for which science furnishes no answer. In his physical organization man differs but little from the lower animals. In this he is brother to the beasts that perish, having the same nature, needs, and liabilities. If he is “fearfully and wonderfully made,” so are they; in agility and strength many of them far surpass him. His peculiarities of form and structure do not secure, and, it may be safely said, were not intended to secure physical superiority, but rather to fit the organization for the indwelling of the rational soul, that is his distinguishing characteristic.
Has been made the subject of much diligent research and study. Some facts respecting the physical elements and structure of the sun and planets have been ascertained with reasonable certainty, but much is still in doubt. Assuming that the essential properties of matter are the same everywhere, we may tell with assurance of what the sun and stars are made, provided all solar and stellar phenomena are explained by physical laws that are understood, and in operation around us. This has been done in part, but not so as to harmonize the views of all astronomers. Since the use of the spectroscope[5]results have been more satisfactory, and on some questions of much interest, conjecture and theory have given place to certainty. By the decomposition of sunbeams or pencils of solar light, the refracted rays show the presence of several distinct chemical elements. Finding by a qualitative analysis that there is iron, copper, zinc, nickel, sodium, and other terrestrial substances in the solar and stellar spectra, we know that they enter into the composition of those celestial bodies. But in what proportions or combinations they exist is not known.
Who has not seen a shooting star? For a moment the bright objects dart through greater or less spaces in the heavens, and then disappear. Those of inferior size give but little light, and are seldom seen unless the eye is, at the time, directed toward the space they traverse. Occasionally one flames out with such brilliancy as to light up, for a moment, the whole heavens. These are called meteors—a name quite proper for both classes, and only the very ignorant suppose any of them to be real stars. They come singly, two or three in an hour, or in showers, such as were witnessed in 1833. When of such size that they strike the earth before being consumed by their intense heat, they are aerolites, or meteoric stones. Great masses of these are found in different places, and show such a peculiar combination of their chemical elements as to distinguish them from all other stones; and mineralogists generally conclude they were not formed on the earth. Whence they come is not certainly known. That they were formed by an aggregation of their materials in our atmosphere seems incredible. Nor were they thrown off by some great convulsion,from the moon, with force sufficient to carry them beyond the attraction of that body. Perhaps most astronomers now believe, on what they think sufficient evidence, that the celestial spaces are occupied by innumerable small bodies moving round the sun, of whose nature and orbits nothing is certainly known. The earth, it is supposed, while making its annual circuit, must be constantly encountering them, and, as in passing rapidly through the upper region of the atmosphere they take fire and burn, the shooting star or meteor is simply the light of that flame. The mechanical production of heat, now well understood, shows why they burn. The rapid motion of the earth, especially if it be duplicated by that of the minute body striking through its atmosphere, would generate heat sufficient to quite consume the meteoroids; so that generally their solid substance is dissipated before they reach the ground. Sometimes the heated aerolite explodes when in such proximity to the earth that the fragments fall before they are consumed.
That most interesting atmospheric phenomena, the Aurora Borealis, though so familiar, has never been fully explained. It is rarely seen in equatorial latitudes, but increases in frequency and brightness as we go north, even to the arctic circle.
In this latitude all observers may at times notice two distinct forms of the aurora. The one, as we often see it, has a cloud-like appearance, with a soft radiance permeating it, and seems a vast, irregular patch of mellow light, ever changing, and at times showing a slightly reddish or purple tinge. It is more frequently seen near the northern horizon, having the form of a beautiful arch, the ends of the segment apparently resting on the horizon, and the middle, or crown, a few degrees above it. The other takes the form of streamers, reaching far up toward the zenith. Gently curved, like the celestial sphere on which they are projected, they are not stationary, but almost constantly in motion, but soon resuming their former position, spreading themselves out like immense flags, with their numerous silken folds, ever dancing, quivering, undulating, as if stirred by some gentle breeze, though all else seems in calm repose. To say that the phenomena are electrical, would, probably, not be the whole truth, though evidence is not wanting that the aurora is in some way connected with the electricity and magnetism of the earth and its atmosphere. Practical telegraphists testify that during a brilliant display of “northern lights” such strong, irregular currents of electricity pass along the wires that it is difficult to send a dispatch; at other times the currents are so strong that they can communicate without the battery.
There is, perhaps, about as much against the theory of a purely electrical origin, as in its favor, and, on the whole, we conclude that the Aurora Borealis is one of the things respecting which modern observations have suggested more difficulties than modern science is yet able to explain.
BY PROF. J. T. EDWARDS, D. D.
Director of the Chautauqua School of Experimental Science.
Clearness, accuracy, and brevity are the essentials of good definition. That it is no easy task to combine these, every teacher realizes.
Perhaps it is near the truth to say that fire is that operation in nature which at the same time evolves heat and light. Theoperationis, at the present time, supposed to be a certain vibration of ethereal or more solid substances. All matter is in motion. Whence this motion was first derived no philosopher can tell, unless he goes back to that primal source of both matter and motion, which in the beginning created the heavens and the earth, and said, “Let there be light, and there was light.”
Prof. James Dwight Dana[1]declares that the first act of creative power must have been heralded throughout the universe by a flash of light. Thus the geologist unites with the scriptural narrator, in the statement that light and heat belonged to the first day of creation, although scoffers for a long time ridiculed the idea that light could exist without the sun.
All space is supposed to be filled with a substance called ether, and that it permeates even solid material. When, for any reason, the natural motion of the molecules of matter is much increased, these molecules have the power of imparting their vibration to the ether in contact with them, and that in turn may produce vibrations in other substances, and if these vibrations come in contact with the nerves of touch, there follows the sensation of warmth or heat. If the vibrations of the ether are still more rapid, when they fall upon the retina, we have the sensation of sight, and we call the agent light. Heat and light, then, are the same. In one instance the vibration is capable of affecting one set of nerves, and in the other, two sets of nerves. The heat-vibration can be discovered by the sense of touch alone, but the light-vibration may be detected both by the eye and the touch.
This variation in sensations, when produced by the same cause, may be illustrated as follows: Apply some salt to the tongue, and place some also in a wound, the two sensations are entirely unlike. Again, the vibrations of a body may be so slow that we can discover them by touch, as showing resistance, or so rapid that they are reported to the ear as a shrill sound, or they may be increased so intensely as to evolve heat, and if still more increased in rapidity, affect the eye as light. The spectrum affords us still another illustration of this truth. Pass through a prism a single ray of light, lo, it appears on the screen in all the colors of the rainbow. Nor is this all;betweenthe bright colors, andbeyondthe violet and the red are invisible lines, and the various parts of the spectrum, although all are produced by the one ray, are capable of creating quite different results. If one should place a delicate thermopile below the red color, it at once reports heat, although the eye sees nothing there. The beautiful colors of the spectrum flash their light into the eye, raise the temperature of the thermometer and affect chemical transformations, while, still more wonderful, the dark lines above the violet, though unseen and not indicated by the thermopile, act upon the sensitized plate of the photographer with decided chemical force. Thus changes in vibrations as to rapidity, length and direction make changes in the resulting sensations.
Light-waves are always heat-waves, and heat-waves may, by increasing the rapidity of the vibrations, become light-waves. It will be observed that three of our senses are close akin. Hearing, feeling (as regards warmth) and seeing are all produced by vibrations. It is quite in accord with the doctrine of modern science to believe that the morning stars did “sing together,” for light is essentially rhythmic, and to senses adapted to the perception of their harmonies, the sunbeams would make music. The various colors of the spectrum differ solely in the wave-lengths of their vibrations. The red corresponds to low pitch in music and the violet to high pitch. As the vibrations of air striking upon the ear increase in rapidity, the soundrises in the scale. There is this difference between the ear and the eye—the former, if trained, can detect all the tones in a chord of music, while the latter, however cultivated, can not discern the varied colors blended in white light.
There must be sixteen vibrations in a second to produce a continuous sound. When these vibrations reach thirty-eight thousand in a second they become inaudible.
Eisenlohr[2]informs us that the red color in the spectrum has four hundred and fifty-eight trillion vibrations in a second, and extreme violet seven hundred and twenty-seven trillions. The former yields 37,640 waves in an inch, and the latter 59,750 waves in the same space. Now mark another beautiful analogy between sound and sight. In looking at the spectrum we can not discern the light or heat below the red color, because the waves are so slow. Ascending the gamut of color, the rapidity of the vibrations increases, until justbeyondthe violet it becomes so great that the eye can detect no color.