PREPARING THE GROUND.—PLOWING AND HARROWING WITH A CATERPILLAR ENGINE.
Sugar beets require deep plowing, ten to fourteen inches, or twice the usual depth. When using horses, farmers are inclined not to plow deeply enough to secure maximum results, and some of the factories have put in power plows which turn six furrows and harrow the land at the same time. They plow and harrow the land of beet farmers for $2.50 per acre, which is about one-half of what it costs the farmers to plow equally deep with horses. The traction engines also are used for hauling train wagon loads of beets to the factory. In some localities farmers are banding together and purchasing engines for plowing and hauling beets. The outfit illustrated above costs about $4,500.
DRILLING THE SEED.
Beets are drilled in rows, usually eighteen inches apart, 18 to 25 pounds of seed being drilled to each acre. Practically all the beet seed used in America is grown in Europe, principally in Germany, but it has been demonstrated that superior seed can be produced in the United States. Sugar-beet seed growing requires five years of the utmost skill, care and patience, from the planting of the original seed to the maturing of the commercial crop which is sold to the trade. The factories contract for their seed for three to five years in advance, sell it to farmers at cost price, and deduct the amount from the payment for beets.
HOW THE BEETS ARE GROWN
BLOCKING AND THINNING.
When the beets are up and show the third leaf they should be “thinned.” Unless thinned at the proper time the pulling up of the superfluous beetlets injures the roots of the remaining ones. Scientific experiments in Germany, where all other conditions were identical, showed that one acre thinned at the proper time yielded 15 tons; the next acre, thinned a week later, yielded 13¹⁄₂ tons; the third acre, thinned still a week later, yielded 10¹⁄₂ tons; and the fourth acre, thinned three weeks after the first, yielded 7¹⁄₂ tons.
The men in the foreground are “blocking” the beets, leaving a bunch of them every eight inches. Those in the rear are “thinning,” or pulling up the superfluous beetlets, leaving one in a place, eight inches apart.
READY FOR THE HARVEST.
This field of beets yielded 20 tons to the acre. Ex-Secretary of Agriculture James Wilson is convinced that when American farmers become expert in beet culture they will average to produce more than 20 tons per acre because of the superiority of our soils. The ideal factory beet weighs about two pounds, and a perfect “stand” of such beets, one every eight inches, in rows eighteen inches apart, would yield 43¹⁄₃ tons per acre. The present average yield in the United States is about 10 tons per acre, while the hitherto “worn-out soils” of Germany yield 14 tons per acre, or 40% more than is secured from our “virgin soils.”
HUGE BINS TO HOLD THE BEETS AT FACTORY
TOPPING THE BEETS.
After the beets are plowed out they are topped or cut off by hand and the tops are fed to stock, for which purpose they are worth $3.00 per acre. They are topped just below the crown and the factories require that they be so topped as to remove any portion which grew above the ground, as such portion of the beet contains but a small percentage of sugar. The beet will grow in length, and, if as a result of shallow plowing or coming in contact with a rock it cannot grow downward, it will grow upward and out of the ground, thus necessitating a deeper topping and consequent loss to the farmer.
DUMPING CARS AT FACTORY WITH HYDRAULIC JACK.
Beets arriving at the factory by rail from receiving stations either are stored in bins until needed or are floated directly to the beet washers. If to be used at once, they are dumped, as shown above, and slide directly into a cement flume filled with warm water, which has been pumped to its upper end, and is flowing in the direction of the beet end of the factory. In whatever manner they may be received, they first are weighed, and as they are dumped, a basket is held under them to catch a fair sample of both beets and the loose dirt, which the car or wagon contains. These samples, properly tagged, are conveyed to the beet laboratory, where they are washed, and trimmed if not properly topped, and the difference in the weight of the sample beets as received and their weight when washed is called the “tare.” Whatever percentage this amounts to is applied to and deducted from the weight of the car or wagon load. A sample of these beets then is tested by the polariscope for its sugar content and its purity; farmers often being paid a stipulated price per ton for a beet of a given sugar content and 25 to 33¹⁄₃ cents per ton additional for each extra degree of sugar which they contain. The tare rooms and the beet-testing laboratories are open to any one, and in some localities the farmers’ associations employ experts to tare and analyze each sample of beets.
MILLIONS OF BUSHELS OF BEETS
FACTORY BEET BINS FILLED TO CAPACITY.
As they arrive by rail from receiving stations, or by team, or traction engines from the farm, beets are stored in bins or sheds, the capacity of which ranges from 6000 to 35,000 tons per factory, depending upon location and general climatic conditions.
The bins are V shaped, about 3 feet wide at the bottom, 20 to 30 feet at the top, and they are 20 to 30 feet high. As beets are needed, beginning at one end of the bin the loose three-foot planks at the bottom are removed one at a time, and with hooks attached to long poles the beets are rolled into the flume or cement channel below, in which they are floated into the factory. This is not only to save labor, but to loosen up the dirt which attaches to the beets, thus partially washing them. The water which is used in the flumes is warm water from the factory.
TYPICAL AMERICAN BEET SUGAR FACTORY.
These factories cost from half a million to three million dollars. They consume from 500 to 3,000 tons of beets per day, and during the “campaign,” which usually lasts about three months, will produce from 12 to 75 million pounds of granulated sugar. There are 73 of these factories, located in 16 States, from Ohio to California. During the operating season they give employment to from 400 to 1000 men each.
WASHING THE SUGAR BEETS
CHEMICAL LABORATORY.
In a beet-sugar factory each set of apparatus for performing a given process is termed a “station.” In the chemical laboratory the juices and products from each station are tested hourly to check up the correctness of the work and to determine the losses of sugar in each process in the factory.
CIRCULAR DIFFUSION BATTERY.
After being floated in from the sheds the beets are elevated from the flume to a washer, where they are given an additional washing before being sliced. From the washer they are elevated and dropped into an automatic scale of a capacity of 700 to 1500 pounds. From the scale they pass to the slicers, where with triangular knives they are cut into long, slender slices, which look something like “shoestring” potatoes. These slices drop through the upright chute seen at the right side of the picture, and are packed tightly into cylindrical vessels holding from two to six tons each; the battery consisting of eight to twelve vessels arranged either in a straight line or in circular form. Warm water is run into these slices, and coaxes out the sugar as it passes from one vessel to the succeeding ones. After passing through the entire series of vessels the water has become rich in sugar, of which it contains from 12 to 15 per cent, depending upon the richness of the beets. It then is drawn off and is called diffusion juice or raw juice. This is carefully measured into tanks and recorded. As this juice is drawn off the vessel over which the water started is emptied of the slices from the bottom, the exhaust slices containing in the neighborhood of ¹⁄₄ to ¹⁄₃ per cent of sugar. These slices are carried out from the factory in the form of pulp and fed to stock, as explained later.
HOW THE SUGAR IS TAKEN FROM THE BEET
CARBONATATION AND SULPHUR STATION.
Warm raw juice is drawn into the carbonatation tanks and treated with about 10 per cent milk of lime—about like ordinary whitewash. This lime throws out impurities, sterilizes the juice and removes coloring matter. Carbonic acid gas from the lime kiln is forced through the lime juice in the tank, throwing out the excess of lime, converting it into a carbonate of lime or chalk. Tests are taken here by the station operator to show when the process is finished.
FILTER PRESSES.
From the carbonatation tanks the juice is pumped or forced through filter presses consisting of iron frames so covered with cloth that the juice passes through the cloth as a clear liquid, leaving the lime and impurities precipitated by it, in the frame, in the form of a cake. This cake, after washing, is dropped from the presses and conveyed out of the factory. It contains from one to two per cent of its weight in sugar, which constitutes one of the large losses of the process. It also contains organic matter, phosphate and potash, besides the carbonate of lime, which makes it an excellent fertilizer, all of which is used in Europe on the farm, but so far to too small an extent in America.
EVAPORATING THE WATER FROM THE SUGAR
EVAPORATORS.
After a second, and sometimes a third carbonatation and filtration, the juice is carried to the evaporators, commonly called the “effects,” usually four (4) large air-tight vessels furnished with heating tubes running from 3000 to 7000 square feet in each vessel. A partial vacuum is maintained in these evaporators which makes the juice boil out at a low temperature, thus preventing discoloration, and to a large degree the destruction of sugar which will come about by high temperature. There always is, however, some unavoidable loss of sugar in this apparatus. The juice passes along copper pipes from first to last vessel, becoming thicker as it does so. It comes into the first vessel at 10% to 12% sugar and is pumped out of the last one so thick that it contains about 50% of sugar.
VACUUM PANS.
After a careful filtration, the juice that comes from the evaporators, and is called thick juice, is pumped to large tanks high up in the building, and from these is drawn into vacuum pans. These are large cylindrical vessels from 10 to 15 feet in diameter and from 15 to 25 feet high, with conical top and bottom, built air-tight. Around the inner circumference they are furnished with 4- to 6-inch copper coils, which have a heating surface of 800 to 2000 square feet. Exhaust steam is used in the evaporators, live steam in the pans, the juice in both being boiled in a vacuum to prevent discoloration and reduce losses.
After considerable thickening by this evaporation, minute crystals begin to form. When sufficient of these have formed, fresh juice is drawn in and the crystals grow, the operator governing the size of the crystals to suit the trade. If small crystals be desired, a large quantity of juice is admitted at the outset, while if large crystals are desired, a small quantity of juice first is admitted, and, as it boils to crystals, fresh juice gradually is added to the pan, and the crystals are built up to the desired size. The operator of this pan, known as the “sugar boiler,” is one of the must important men in the factory. The water furnished the condensers of these vacuum pans and the evaporator goes to the beet sheds and is used for floating in the beets. It amounts to from 3,000,000 to 8,000,000 gallons every 24 hours, depending upon the size of the factory, and must be very pure.
HOW SUGAR IS GRANULATED
FRONT VIEW OF CENTRIFUGAL MACHINES.
The mass of crystals with syrup around them and containing about 8 per cent to 10 per cent of water is let out of the vacuum pan into a large open vessel called a mixer, beneath which are the centrifugal machines. These are suspended brass drums perforated with holes and lined with a fine screen. They are made to revolve about 1000 times to a minute, and the crystal mass of sugar rises up the side like water in a whirling bucket. The centrifugals force the syrup out through the screen holes, leaving the white crystals of sugar in a thick layer on the inner surface. These are washed with a spray of pure warm water and then are ready for the dryer.
SUGAR GRANULATOR OR DRYER.
The damp white crystals from the centrifugal machine are conveyed to horizontal revolving drums about 25 feet long by 5 to 6 feet in diameter. These drums are furnished with paddles on the inside circumference, the paddles picking the sugar up and dropping it in showers as the drum revolves. Warm dry air is drawn through and takes the moisture out of the sugar, which now is ready to be put in bags or barrels for the market.
BY-PRODUCTS OF THE SUGAR BEET
CRYSTALLIZERS.
The syrup that was thrown off from the crystals in the centrifugal machines is taken back to the vacuum pan, evaporated in the same manner as previously described, and from the vacuum pan goes into the crystallizers to carry the process of crystallization as far as it will go. These contain from 1000 to 1600 cubic feet of the crystallized mass which remains in them from 36 to 72 hours, during which time it is kept in constant motion by a set of slowly revolving paddles, or arms, to facilitate further crystallization. From the crystallizers it goes to the centrifugal machines, where the syrup is separated from the crystals as before. The crystals are remelted and go in with the thick juice for white sugar. The syrup, still containing a large amount of sugar, goes out to be sold as cattle feed or to an Osmose or Steffens process, where a portion of the remaining sugar may be recovered. This lost syrup constitutes the largest loss in the entire process. It contains all the impurities of the beet juice not removed by the lime. These impurities prevent more than one and one-half times their weight of sugar from crystalizing, and make what is called molasses.
A SEA OF BEET PULP.
For a century the high feeding value of sugar-beet pulp has been recognized in Europe, but until a few years ago millions of tons of this valuable by-product rotted about American beet-sugar factories, as shown above, because American farmers could not be made to believe it possessed sufficient value to pay for hauling it back to the farm.
MACHINE THAT FILLS, WEIGHS AND SEWS THE BAGS OF SUGAR
SACKING ROOM.—SHOWING AUTOMATIC SCALES AND SEWING MACHINE.
After the moisture has been thoroughly removed in the granulators or dryers, the sugar drops directly to the sacking room through a chute, at the lower end of which the top of the double bag is attached. The sugar flows directly into the sack, the flow being cut off automatically with each 100 pounds, when an endless belt conveyor passes the upright sack past the sewing machine at the proper speed and the product is sealed ready for storage or shipment.
While it requires from 400 to 1000 men to man a factory, not a human hand has touched either beets or product since the beets were topped in the field, and at no stage of the operation could flies or vermin or filth come in contact with the product, which from the beginning has been subjected to continuous high temperatures.
Pictures herewith by courtesy of United States Beet Sugar Industry.
You do not need to be told what organ of the body we use in exercising the sense of smell. You can prove that easily to yourself by getting the nose within range of a distasteful smell.
We do not use all of the nose to smell with, and the nose is useful to us in other ways besides this. We use the nose a great deal in the act of respiration or breathing, and it is also useful in helping us to make sounds, form words, and, though you may not have known it, helps our sense of taste.
We smell things by means of the olfactory nerves which are located within the nose. The entire interior surface of the nose is covered with a membrane. The ends of olfactory nerves, or the nerves which give us the sensation of smell, are in this membrane, and the air, which is filled with the odor of things we smell, passes over this membrane, and thus the ends of the nerves feel the odor and cause sensation of smell in the brain. The nerves of smell do not, however, go all through this membrane.
There are other nerves in the nose, however, besides those which give us the sensation of smell. These are also very sensitive and serve to make the nose exercise other functions when the inside of the nose is hurt or tickled. When a foreign substance, one of the many smaller particles which are constantly floating in the air, gets into the membrane in the nose, it irritates these nerves and often causes us to sneeze, which is only nature’s effort to drive out this foreign substance and clean out the nose. Smell is one of the lesser of the five senses which we possess. It is one of what has been called the chemical senses. The sense of smell does not act at any great distance. This sense could be made of more value to us if we developed it. Some people have a more highly developed sense of smell than others. The lower animals have a much keener sense of smell than people. A great many of them can follow a trail for miles merely by the smell of the foot-prints, and it is said that a deer will note the presence of man or any other animal that may subject him to danger even when miles away, the odor being carried to him through the air.
The sense of taste is closely associated with the sense of smell. In fact we do a good deal of what we think is tasting by using our sense of smell. A cold in the nose will sometimes destroy almost altogether the taste of food, so that there is a very close connection between the sense of taste and the sense of smell.
The sense of taste comes to us through the tongue, which is the principal organ of taste. The remainder of our sense of taste lies in the surface of the palate and in the throat. As in the case of the other senses, the sensation of taste is given us through nerves, the ends of which are all through those parts of the tongue, the palate and the throat, which contribute to this sense. More nerves of taste are located in the back part of the tongue than on the front, and it is said that when you have to swallow a bad dose of medicine it won’t taste so much if you put it on the front part of your tongue and then swallow, because there are so few tasting nerves there. The extreme tip of the tongue, however, is very thickly covered with the ends of the taste nerves. In like manner one could have the front end of the tongue cut off and still retain most of the sense of taste.
Now, in order to produce the sensation of taste, the substance to be tasted must come in contact with something which mixes with it and causes the sensation of taste. This is what happens when we taste anything. The juices or liquids which are caused to flow when anything is put into the mouth act on the substances which enter and give the taste nerves a chance to taste them. Really the nerves of taste are so placed in the mouth as to be regular guards or inspectors of what shall go into the stomach. You can see how well they are arranged. In the tip of the tongue quite a few of them; in the back part of the tongue a great many nerves, for from there the food goes into the throat, which delivers it to the stomach; then those in the palate and in the throat. They are arranged so that the taste nerves have ample opportunity to test what comes in and to give warning to the brain of what is being sent to the stomach. Sometimes the things that come into the mouth are so distasteful to the nerves of taste that they refuse to hand it over to the stomach, but instead cause the distasteful substance to be thrown out again immediately.
It is said that a good rule to follow in eating would be to swallow only such things as are pleasing to the sense of taste. On this principle many children would decide to eat nothing but candy, but do you know, if you tried that, the continuous tasting of sweets by our sense of taste nerves would cause them to repel further insertion of candy after a while. You know that too much of a good thing is bad for you, and that is what makes you feel badly when you have eaten too much of one thing.
HOW WE SEE
THINGS
Of course, it is the eyes with which we see things. When we think of the things with which we see, we think only of eyes, which give us our sense of vision, but there are certain forms of animal life which have no eyes but which have what are called eye spots or eye points, which are sensitive to light and which are merely spots. These eye spots may be located in any part of the body, and are often found in great numbers on the same body. These rude eyes are, however, not real eyes. They are, as has already been said, sensitive to light, but are found only in some of the very low forms of animal life which live in the water. A real eye is an organ in which the parts are so arranged that optical images may be formed.
As animal life becomes developed to a higher scale, the parts which contain the making of real eyes become more distinct although, of course, the eyes themselves are not so highly developed as in man. One of the first kinds of life which has eyes with a definite structural character are the worms, snails, etc., though their sense of vision is more or less dim.
When we come to the family of mollusks, however, low down in the scale of life though they are, we find them to possess eyes which enable them to see almost as well as animals which have a backbone, although this kind of eyes is constructed in a very different manner than the eyes of vertebrate animals referred to. As we ascend the scale of animal life in the study of eyes, we come next to the crustaceous, which is an important division of animal life that embraces the crabs and lobsters, shrimps, crawfish, and insects such as sand-hoppers, beach-fleas, wood-lice, fish-lice, barnacles. The eyes of such animals are quite developed, but the number that each will have varies. Some have only a single eye and others two, four, six or eight, but only certain kinds of this class of life have more than two eyes. The spiders generally have the most.
In vertebrates, which is the class of animal life to which we belong, the number of eyes is almost always two and no more. The eyes are formed in special sockets in the skull, which are called eye sockets or orbits. This arrangement of placing them in a socket is of great advantage because the eye is thus protected from chance of injury except from one direction—the front. These animals have also eyelids, eyebrows and eyelashes, which serve as a further protection to the eyes.
The principal parts of the eye are arranged in a globe-like ball called the eyeball. This eyeball is movable in the socket under control of various muscles. The eyeball is almost surrounded by a membrane which is opaque in most parts, but very transparent at the front. This transparent portion of the surrounding membrane is called the cornea, and is quite hard. This is the outside coat of the eye. The second coat of membrane consists of parts of various names and contains the iris. The third coat is the retina, which is the end of the optic nerve entering the eye full from behind and expanded into a membrane which spreads out over the second coat.
The retina or optic nerve receives optical impressions focused upon it by the crystalline lens. These impressions are carried along the optic nerve to the brain, and the brain then receives the sensation of seeing the image. The eyeball is hollow, and its three surrounding coats form what is practically the same as the interior of a camera. The crystalline lens of the eye acts the same as the lens in the camera. This crystalline lens is suspended within the eyeball right in front of the transparent opening in the front of the eyeball, and when the rays of light strike this lens it focuses them on the retina, which is the same as the film in your camera.
We can hear because nature has provided us with a very wonderful organ called the ear and which catches the sound waves that come through the air into the ear and make a part of the ear vibrate.
In man and mammals the ear is generally found on the outside of the body, but the principal part of the ear is located within the skull. What we call ears are only the funnel-shaped extensions on the outside of the head which are not so very important so far as hearing is concerned, because they only help the real ear to hear more easily. The outside of the ear gathers in the sound waves and, because it is much larger than the little hole which takes the sounds in to the real ear, we can detect more sounds by having this funnel-shaped arrangement on the outside.
The inside of the ear contains an eardrum or tympanum which is separated from the outside part of the ear by a membrane. Behind this eardrum is the real hearing part of the ear in a labyrinth containing the nerves of hearing.
Now, when a sound wave strikes the membrane which hangs over the opening before the eardrum, the membrane vibrates and transmits the sound wave through the eardrum into the inner ear which contains the ends of the nerves by which we hear. These nerves, on receiving the sensation, transmit it to the brain which thus records the impression of sounds.
As we descend the scale of animal life from the mammals downward, the ear becomes a more and more simple organ. In the vertebrates which are not mammals, there is no external ear at all, and we find great simplifications of the ear the lower down in the scale we go.
Before people had individual names, the savage people who lived in clans or tribes referred to themselves in the name of some natural object, usually an animal which they assumed as the name or emblem of the clan or tribe. These names never applied to one individual more than another, but only to the clan or tribe, so that everyone in a tribe which had taken the “wolf” for its emblem was known as “Wolf.” Later on they began to distinguish individuals by giving them additional names characteristic of the individual, such as “Lonely Wolf,” “Growling Wolf,” or other names. The name of this animal was then the emblem of one tribe. They, therefore, placed this emblem upon their bodies, their clothes, utensils, etc. Through this, these emblems also became at times idols of worship and so they erected poles upon which their emblems were engraved. The word totem is a North American Indian word meaning “family token.” The tribes called themselves after animals from which they believed themselves descended.
The perfume or smell of the flower comes from within the plant itself. The perfume arises from an oil which the plant makes, and just as there are many kinds of flowers, so almost every flower has a different smell. Of course, flowers belonging to the same family or species are likely to develop different smells. The oils produced are what are known as the volatile oils, which means “flying oils,” because, if extracted from the flower and placed in a bottle and the cork left out, they will vanish into the air. Without this quality we could not, of course, smell them at all.
Man uses these oils to provide himself with perfumes, but the plant or flower has another purpose than this. The perfume is not made for man’s use, but for the use of the plant itself. In the plant and flower world the smell of the plant which is in the flower is a part of the scheme whereby plants reproduce themselves.
Every plant in order to reproduce itself must produce a seed. The flowers are in most cases the advance agent of the coming seed. Each flower produces within itself a little powder called the pollen, but as plants are like people—also male and female—they are dependent upon each other for the production of a perfect seed. Some of the pollen from the male plant must be mixed with the pollen of the female plant before a perfect seed results.
Naturally, the nearest male plant to a female plant may be quite some distance off. How, then, is the pollen from the male plant to mix with the pollen of the female plant? In some cases it is the wind which blows the pollen powder from one to the other, and this thus leaves the development of a perfect seed from a perfect flower open to chance. In the case of perfumed flowers, however, which are mostly low-growing plants, the wind cannot be depended upon. So nature gives to such plants the power to make the perfumed oil and the busy bee does the rest. The perfume being a flying oil rises up into the air and attracts the bee. He is gathering honey and visits in turn all the flowers to which he is attracted. He lights on a male flower and gathers in his honey, and incidentally acquires on his legs, without intending to do so, some of the pollen of the male flower. Then he flies about to the next flower, and to others, and sooner or later he will come across a female flower of the same kind as that from which he secured the pollen on his legs. When he thus enters the female flower, the pollen on his legs mixes with the pollen of the same kind of the female flower, and quite unintentionally the bee helps thus to make the perfect seed. It is not a part of a bee’s business to do this carrying. It only happens that he does this in connection with his regular business of gathering honey. It is a wonderful thing which may be noted here that the pollen from a male of any flower will not mix with the pollen of the female of any other kind of flower, but that the same kinds only have attractions for each other. Flowers are given these attractive perfumes in order that they may attract the bees and other insects in this way. The plants or flowers which grow closest to the ground have generally the strongest and most far-reaching smells. This is so that they will not be overlooked.
Leaves are of different shapes because they belong to different families of plants or trees. They are a good deal like people in this respect. Hardly two people in the world look exactly alike, but there is a distinct family resemblance in members of the same family. It is difficult to say just what happens inside the tree to determine the shape of the leaf and that causes them to possess different shapes from others. The shape of the leaf is a mark of identification of the family to which the tree or plant belongs, just as you can tell from a dog’s ears and from other characteristics what his breeding has been. In the case of plants and trees however it is quite probable that the shape and texture of the leaves has been developed as the result of the conditions under which the plant grows. A plant or tree throws off oxygen and takes in carbonic acid gas through the surface of the leaves. To thrive and be healthy it must secure just the proper amount of this food and as the quantity of food taken in depends upon the amount of surface exposed through the leaves, each particular tree or plant has developed in its own direction in this respect until this feature of their structures has been adjusted properly to their needs. It is a good deal like the radiation of heat in your home.
When the plumber gets ready to put in the radiators in the home he figures the cubic measurements of the room and then puts in a radiator, the outside surface of whose pipes, is in the right proportion to throw off sufficient heat to fill the room or heat all the air in the room. It requires a certain number of square inches of radiator surface to heat each cubic foot of air space and a good plumber can figure this to a nicety. If he puts in a radiator however that has not sufficient number of square inches on the outside of the pipes, the room will not be heated properly. In the same way, the trees, require that their leaves have a certain amount of square inches of surface space in proportion to the size of the tree, to enable them to do what is required of them and this is arranged by nature so that the trees grow naturally, and no doubt the shape of the leaves has something to do with this.
All roses are not red. Some are white and others pink or of still another color. The color of the rose, and in fact the color of all flowers is due to the way they absorb and reflect the sunlight. In the case of the red rose, the something in the plant that determines the color, absorbs all the other colors in the sunlight and reflects the pure red rays and that makes the color of the red rose. You cannot see the color of any flower when it is perfectly dark. That is because they have no color of their own, but only the colors which they reflect when in the sunlight or some other light. The question of colors is more fully explained in another part of the book.
As a matter of fact plants and trees do grow downward as well as up. There is a part of each called the root whose business it is to grow down and take certain things necessary to the life of the tree out of the ground. But the part we see above the ground and which is the part we generally think of only when we think of plants or trees.
The tree or plant, in order to grow properly, and eventually produce flowers and perfect seeds, must have sunshine and carbonic acid gas, and it is the business of the leaves and other parts above the ground to get these out of the air for the good of the plant or tree. So they start to grow toward the sun. It is easy to prove how a plant will turn toward the light. Take notice of the plants in the flower pots at home. Set one of them on the window sill inside the window where the sun can shine on it and notice how quickly the leaves and branches will be bent over against the window pane. Turn it completely around then so that the plant leans away from the sunlight and watch it for a day or two. Before long you will find that it has not only straightened itself completely out but started to lean toward the window glass again so as to get as near the sun as possible. Most plants, if kept where the sunlight cannot touch them, will die. The sunlight is a necessary part of their lives.
A great many, in fact the large percentage of plants, live only during one season. This kind of plant actually dies completely after, in the natural course of growth and flowering, it has produced its seed which is the method by which such plants are reproduced. Other plants only appear to die in the winter. Parts of them, such as the leaves and flowers actually die, but the roots and stalks of such plants do not die in winter. The part that represents the life in them goes to sleep and lies dormant until the light and warmth of summer bring forth the leaves and flowers again.
The flowers, however, always die and the same flowers never appear again but others just like them appear in their places.
Even in hot countries where there is no winter, the plants must go through a period of rest or sleep, although this change is not so marked in plants which grow in these hot countries.
To get at the answer to this question, we should pick out one kind of plant like the creeping ivy vine. If we examine same as it climbs a brick wall, we find that it sends out little shoots which attach themselves around the little rough places in the bricks of the wall which, if examined under a microscope are quite large apparently—at least they are large enough for the tiny creepers of the ivy to hold on to. Of course, if there were only one little “shoot” to reach out and take hold of the rough spots in the wall, the vine could not cling to the wall, but the vine puts out a great many of these shoots—which it would perhaps be best to call “clingers” and as each helps a little to hold on, the great number all holding on together enable a quite heavy vine to hang on to an apparently smooth wall.
Some vines have actually the ability to send out little suckers which are made on the same principle as the boys’ sucker (a circular piece of leather with string attached to the middle with which a boy can pick up stones) and such plants can cling to and climb up an almost perfectly smooth wall.
The thorns of roses and other plants which have thorns originally grew for the purpose of enabling the plants to fasten themselves on to other things thus helping them to climb. Many plants with thorns are permitted to grow now in places where they can use their thorns for climbing but many others with thorns are cut down by the gardener to make the plants shapely and to make them produce more flowers and less branches, but they keep on growing their thorns just the same.
Yes, indeed, plants do breathe. To breathe is just as important to the life of a plant as it is to a boy or girl. Plants do not have lungs like boys and girls and grown up people, but they find it necessary to breathe. You know, of course, that fishes breathe, but they haven’t any lungs either, even though they belong to the animal kingdom. Fishes do not, however, breathe the air in the same form as we do because they must use the air which they find in the water. That is why we say fishes drown when on the land. They cannot breathe air in the form in which we are able to use it any more than people can breathe the air in the water.
Breathing, however, is necessary to all living things and the gas which we take in when breathing is oxygen. There is oxygen in the water as well as in the air. Things which live in the air take their oxygen out of the air and things which live in the water get their oxygen out of the water. For this purpose it is necessary for plants and animals that live under the water to have a breathing apparatus especially adapted for getting oxygen out of the water.
The act of breathing consists really of two actions. Taking something into the body and expelling something. Every living thing inhales and expels in breathing. We take in oxygen and expel it again but when it comes out it has added something to it and the combination or result is carbonic acid gas—so we take in oxygen and expel carbonic acid gas.
The lungs of a plant, or what the plant breathes with corresponding to our lungs, are located in the leaves of the plant. Under a magnifying glass we can see the lungs of the leaf quite clearly. In addition to this we know that plants breathe, because if we put them in a vacuum where there is no air they die very quickly. The plant needs air or it will suffocate just as any animal will suffocate under similar conditions. Plants, however, do not make use of the oxygen as they find it in the air. They live on the carbon which they find in the air mixed with oxygen. What happens then is this. The plants take in through their lungs in the leaves carbonic acid gas from which they take the carbon and use it as food, and throw off the oxygen which they cannot use. Human beings and other animals take the oxygen into their lungs and use it and expel carbonic acid gas. The result is that each kind of life is dependent upon the other. If it were not for the plant life, men and other animals would find it difficult perhaps to find sufficient oxygen in the air to keep them alive, and if it were not for the carbonic acid gas which the animals throw off, plants and other vegetable life would have great difficulty in finding sufficient carbonic acid gas to go around.
Most plants, if placed where no light from the sun can reach them, will die very quickly. To prove that a plant needs the sunlight we have only to place it in a dark corner of the cellar and notice how soon it dies. In fact if it were not for sunlight there would be no life on earth at all. The plant or tree drinks in sunlight through the surface of the leaves. In fact the ability to take in sunlight constitutes the real life of the tree or plant. Leaves grow thin and flat in order that as much surface as possible may be exposed to the sunlight. If a leaf were curled up like a hoop only a part of the outside surface would be exposed to the sunlight and the amount of life that a leaf could supply to the rest of the tree would be much less. The leaf is so constructed that when the sunlight strikes down upon its green surface, it changes the carbonic acid gas which it drinks in, into its elements, i.e., it takes out the carbon which goes into the body of the plant and combining with other food and water supplied by the roots causes the plant or tree to grow and then returns the oxygen part of the carbonic acid gas to the air.
The milk turns sour because a little microbe, known as the milk microbe gets into it, and being very fond of the sugar which is in the milk, turns this sugar into an acid.
If we could keep milk entirely away from the air after the cow is milked, it would not turn sour, but as soon as it is exposed to the air these microbes which are constantly in the air, drop into the milk. They are alive, although invisible to the naked eye. If when they drop into the milk it is warm enough for them to get in their work so to speak, they fall upon the sugar in the milk and turn it into the acid. Their attempt to sour the milk can be overcome by keeping the milk at a low temperature in the refrigerator, but as soon as the milk is taken out of the refrigerator and left out long enough to become warm, the microbe begins to work and the milk cannot be made sweet again. If the milk is boiled as soon or shortly after the cow is milked, the sugar in the milk is changed in such a way that the microbe cannot feed upon it.