The Reason Why / A Careful Collection of Many Hundreds of Reasons for Things Which, Though Generally Believed, Are Imperfectly Understood

Because it assists us to comprehend the goodness and power of God.

And it gives us power over the circumstances and associations by which we are surrounded: the proper exercise of this power will greatly promote our happiness.

Knowledge enables us to understand that, in order to live healthily, we require to breathe fresh and pure air. It also tells us that animal and vegetable substances, undergoing decay, poison the air, though we may not be able to see, or to smell, or otherwise discover the existence of such poison. Knowing this, we become careful to remove from our presence all such matters as would tend to corrupt the atmosphere. This is only one of the countless instances in which knowledge gives us power over surrounding circumstances.

Knowledge of Geography and of Navigation enables the mariner to guide his ship across the trackless deep, and to reach the sought-for port, though he had never before been on its shores.

Because the air contains oxygen, which is necessary to life.

Because it combines with the carbon of the blood, and forms carbonic acid gas.

Because we are so created that the substances of our bodies are constantly undergoing change, and this resolving of solid matter into a gaseous form, is the plan appointed by our Creator to remove the matter called carbon from our systems.

Because, in the union of oxygen and carbon, heat is developed.

It is called combustion, which, in chemistry, means the decomposition of substances, and the formation of new combinations, accompanied by heat; and sometimes by light, as well as heat.

Carbonic acid gas.

It is sent out of our bodies by the compressure of the lungs, and mingles with the air that surrounds us.

Pure carbonic acid gas is the heaviest of all the gases. That which is sent out of the lungs is not pure, because the whole of the air taken into the lungs at the previous inspiration has not been deprived of its oxygen, and the nitrogen is returned. Therefore the breath sent out of the lungs may be said to consist of air, with a large proportion of carbonic acid gas.

It consists of oxygen, nitrogen, and carbonic acid gas, in the proportions of oxygen 20 volumes, nitrogen 79 volumes, and carbonic acid gas 1 volume. It also contains a slight trace of watery vapour.

At first, being rarefied by warmth, it is lighter. But, if undisturbed, it would become heavier as it cooled, and would descend.

Because at night, the bed-room being closed, the breath of the sleeper impregnates the air of the room with carbonic acid gas, which, descending, lies in its greatest density near to the floor.

The vegetable kingdom (as will be hereafter explained), the combustion of substances composed chiefly of carbon, the breathing of animals, and the decomposition of carbonic compounds.

It is. In the breathing of animals, the burning of coals, or of wood, or candles, &c., similar changes occur. The oxygen of the air combines with the carbon of the substance said to be burnt, and forms carbonic acid gas, which unfits the air for the purposes of either breathing or of burning, until it has been renewed by admixture with the air.

It is one of the elementary bodies, and is very abundant throughout nature. It abounds mostly in vegetable substances, but is also contained in animal bodies, and in minerals. The form in which it is most familiar to us is that of charcoal, which is carbon almost pure.

An elementary body is one of those substances in which chemistry is unable to discover more than one constituent. For instance, the chemist finds that water is composed of oxygen and hydrogen. Water is therefore a compound body. But carbon consists of carbon only, and therefore it is called a simple, or elementary body.

Because, being composed of carbon that is nearly pure, its combustion gives off a large amount of carbonic acid gas.

It induces drowsiness and stupor, which, if not relieved by ventilation, would speedily cause death.

Because the large amount of carbonic acid gas given off with the breaths of the people, makes the air poisonous and oppressive.

The candles, gas, or fires that may be burning in the rooms where people are assembled. Three candles produce as much carbonic acid gas as one human being; and it is probable that one gas-light produces as much carbonic acid gas as two persons.

In the reign of George the Second, the Rajah of Bengal took some English prisoners in Calcutta, and put 146 of them into a place which was called the "Black Hole." This place was only 18 feet square by 16 feet high, and ventilation was provided for only by two small grated windows. One hundred and twenty-three of the prisoners died in the night, and most of the survivors were afterwards carried off by putrid fevers. Many other instances have occurred, but this one is the most remarkable.

Oxygen is one of the most widely diffused of the elementary substances. It is a gaseous body.

"Stand in awe and sin not: commune with your own heart upon your bed and be still"—Psalm iv.

Because it receives, with every current of air, a fresh supply of oxygen, which unites with the carbon and hydrogen of the coals, causing more rapid combustion and increased heat.

Because oxygen, by itself, is incombustible. The wick of a candle, which retains the slightest spark, being immersed in oxygen, will instantly burst into a brilliant flame; and even a piece of iron wire made red-hot, and dipped in oxygen, will burn rapidly and brilliantly. Oxygen, though non-combustible of itself, is the most powerful supporter of combustion.

Because when we immerse a burning substance into a jar of oxygen, it immediately burns with intense brilliancy; but directly it is withdrawn from the oxygen, the intensity of the flame diminishes, and the oxygen which remains is unaffected.

Because animals placed in any kind of gas, or in any combination of gases, where oxygen does not exist, die in a very short time.

It is found in the air, mixed with nitrogen; in water combined with hydrogen; in the tissues of vegetables and animals; in our blood; and in various compounds called, from the presence of oxygen, oxides.

Nitrogen is an elementary body in the form of gas.

It is chiefly found in the air, of which it constitutes 79 out of 100 volumes. It may be mixed with oxygen in various proportions; but in the atmosphere it is uniformly diffused. It is found in most animal matter, except fat and bone. It is not a constituent of the vegetable acids, but it is found in most of the vegetable alkalies.

Acids are a numerous class of chemical bodies. They are generally sour. Usually (though there are exceptions) they have a great affinity for water, and are easily soluble therein; they unite readily with most alkalies, and with the various oxides. All acids are compounds of two or more substances. Acids are found in all the kingdoms of nature.

Alkalies are a numerous class of substances that have a great affinity for, and readily combine with, acids, forming salts. They exercise peculiar influence upon vegetable colours, turning blues green, and yellows reddish brown. But they will restore the colours of vegetable blues which have been reddened by acids; and, on the other hand, the acids restore vegetable colours that have been altered by the alkalies. Alkalies are found in all the kingdoms of nature.

No; they would immediately die. But a mixture of oxygen and nitrogen, in equal volumes, constitutes nitrous oxide, which gives a pleasurable excitement to those who inhale it, causing them to be merry, almost to insanity; it has, therefore, been called laughing gas.

The mean quantity of the gases contained in the human blood has been found to be equal to 1-10th of its whole volume. In venous blood, the average quantity of carbonic acid is about 1-18th, that of oxygen about 1-85th, and that of nitrogen about 1-100th of the volume of the blood. In arterial blood their quantities have been found to be carbonic acid about 1-14th, oxygen about 1-38th, and nitrogen about 1-72nd.

Such a supposition is highly improbable. It is probably derived from nitrogenised food, just as carbonic acid is derived from carbonised food.

Venous blood is that which is returning through the veins of the body from the organs to which it has been circulated.

Arterial blood is that which is flowing from the heart through the arteries to nourish the parts where those arteries are distributed.

Venous blood contains more carbonic acid, and less oxygen and nitrogen than arterial blood.

It will not burn, nor will it support combustion.

It is thrown off with the breath, mixed with carbonic acid gas, and flies away to be renewed by a fresh supply of oxygen.

In the atmosphere. Nitrogen is said to possess a remarkable tendency to mix with oxygen, without having a positive chemical affinity for it. That is to say, neither the oxygen nor the nitrogen undergoes any change by the union, except that of admixture. The oxygen and the nitrogen still possess their own peculiar properties. Oxygen and nitrogen are found in nearly the same proportions in all climates, and at all altitudes.

Yes. Usually hydrogen is present, which in burning unites with oxygen, and forms water.

Hydrogen is an elementary gas, and is the lightest of all known bodies.

It will not. It proves speedily fatal to animals.

Although it will burn, yielding a feeble bluish light, it will, if pure, extinguish a flame that may be immersed in it. Hydrogen will therefore burn, but will not support combustion.

Because of its strong affinity for oxygen, with which, upon the application of heat, it unites to form water.

In the form of water, where it exists in combination with oxygen. Eleven parts of hydrogen, and eighty-nine of oxygen, form water.

It is never found but in a state of combination; united with oxygen, it exists in water; with nitrogen, in ammonia; with chlorine, in hydro-chloric acid; with fluorine, in hydro-fluoric acid; and in numerous other combinations.

It is; but it is combined with carbon, derived from the coals from which it is made. It is therefore called carburetted hydrogen, which means hydrogen with carbon.

It is driven out of the coals by heat, in closed vessels, which prevent its union with oxygen.

It passes into the air in the form of watery vapour. Frequently it condenses, and may be seen upon the walls and windows of rooms where many lights or fires are burning. Sometimes, also, portions of it become condensed in the globes of the glasses that are suspended over the jets of gas. A large volume of these gases forms only a very small volume of water.

It is diffused in the air, which should be removed by adequate ventilation.

Any proportion over the natural one of 1 per cent. may be regarded as injurious. But toxicologists state that five per cent. of carbonic acid gas in the atmosphere is dangerous to life.

Persons who study the nature and effects of poisons and their antidotes.

Assuming all the lights to be of the same intensity, the degree in which the substances burnt would vitiate the atmosphere may be gathered from the number of minutes each would take to exhaust a given quantity of air. This has been found to be: rape oil, 71 minutes; olive oil, 72; Russian tallow, 75; town tallow, 76; sperm oil, 76; stearic acid, 77; wax candles, 79; spermaceti candles, 83; common coal gas, 98; canal coal gas, 152. Thus it is shown that rape oil is most destructive of the atmosphere, and that coal gas is the least destructive.

It is dangerous, first, by inhalation. There are no less than six deaths upon record of persons who were killed by sleeping in rooms near to which there was a leakage of gas.

It is dangerous, secondly, by explosion.

According to the researches of Sir Humphrey Davy, seven or eight parts of air, to one of gas, produce the greatest explosive effect; while larger proportions of gas are less dangerous. A mixture of equal parts of gas and air will burn, but it will not explode. The same is the case with a mixture of two of air, or three of air, and one of gas; but four of air and one of gas begin to be explosive, and the explosive tendency increases up to seven or eight of air and one of gas, after which the increased proportion of gas diminishes the force of the explosion.

Observe the rule, never to approach a supposed leakage with a light. Fortunately the gas, which threatens our lives, warns us of the danger by its pungent smell. The first thing to be done is to open windows and doors, and to ventilate the apartment. Then turn the gas off at the main, and wait a short time until the accumulated gas has been dispersed.

Being twelve times lighter than common air it rises, and therefore it would be better for ventilation to open the window at the top than at the bottom. But all gases exhibit a strong tendency to diffuse themselves, and therefore they do not rise or fall in the degree that might be anticipated.

One-fiftieth part has been found to have a serious effect upon animals. The effects it produces upon the human system are those of depression, headache, sickness, and general prostration of the vital powers. It is therefore advisable to observe precautions in the use of gas.

By persons of acute powers of smelling it may be recognised when there is one part of gas in five hundred parts of atmospheric air; but it becomes very perceptible when it forms one part in a hundred and fifty. Warning is, therefore, given to us long before the point of danger arrives.

It arises from the decomposition of animal and vegetable substances, containing sulphur and hydrogen. These give off a gas called sulphuretted hydrogen, from which the fætid effluviam of drains and water-closets chiefly arise. We should, therefore, take every precaution to secure effective drainage, and to keep drain-traps in proper order.

Not if it is intelligently managed. The appliances for the regulation of gas are so very simple and perfect, that accidents seldom arise except from neglect. In England 6,000,000 tons of coal are usually consumed in the manufacture of gas, producing 60,000,000,000 cubic feet of gas. And yet accidents are of very uncommon occurrence.

Heat is a principle in nature which, like light and electricity, is best understood by its effects. We popularly call that heat, which raises the temperature of bodies submitted to its influence.

Caloric is another term for heat. It is advisable, however, to use the term caloric when speaking of the cause of heat, and of heat as the effect of the presence of caloric.

The sun is its chief source. But caloric, in some degree, exists in every known substance.

Heat which, in proportion to its intensity, acts variously upon all bodies, causing expansion, fusion, evaporation, decomposition, &c.

Because its chief effects are to expand, fuse, evaporate, or decompose the substances upon which it acts.

Chemical attraction, or affinity, is an attractive agent—as when bodies seek of their own natures to unite and form some new body.

When it holds so much caloric that it diffuses heat to surrounding objects.

When it holds less caloric than surrounding objects, and absorbs heat from them.

By any means which cause agitation, or produce an active change in the condition of bodies. Thus friction, percussion, sudden condensation or expansion, chemical combination, and electrical discharges, all develope heat.

Because they gather into one point, or focus, several rays of caloric as they are travelling from the sun, and the accumulation of caloric developes that intensity of heat which constitutes fire.

In optics, it is the point or centre at which, or around which, divergent rays are brought into the closest possible union.

It is a violent chemical action attending the combustion of the ingredients of fuel with the oxygen of the air.

It imparts heat, which has the effect of expanding both fluids and solids.

It cannot exist without the presence of combustible materials.

It has a tendency to diffuse itself in every direction.

It cannot exist without oxygen or atmospheric air.

Hydrogen, carbon, and oxygen. Hydrogen and carbon exist in the fuel, and oxygen is supplied by the air.

A match made of phosphorous and sulphur (highly inflammable substances) is drawn over a piece of sand-paper; the friction of the match induces the presence of caloric, which developes heat, and ignites the match, the burning of which is sustained by the oxygen of the air. The flame is then applied to paper or wood, and the heat of the flame is sufficient to drive out hydrogen gas, which unites with the oxygen of the air, and burns, imparting greater heat to the carbon of the coals, which assumes the form of carbonic acid gas by union with oxygen, and in a little while all the conditions of combustion are established.

It may exist without fire or light.

It is not sensible to vision.

It makes an impression upon our feelings.

It acts powerfully upon all bodies.

It has no weight.

It attends, or is connected with, all the operations of nature.

It radiates from all bodies in straight lines, and in all directions.

It strikes most powerfully in direct lines.

Its rays may be collected into a focus, just as the rays of the sun.

It may be reflected from a polished surface.

It is more easily conducted by some substances than by others.

Animal heat is derived from the slow combustion of carbon in the blood of animals with the oxygen of the air which the animals breathe.

Latent heat (or more properly latent caloric) is that which exists, in some degree, in all bodies, though it may be imperceptible to the senses.

Yes; there is some amount of caloric in all substances.

A blacksmith may hammer a small piece of iron until it becomes red hot. With this he may light a match, and kindle the fire of his forge. The iron has become more dense by the hammering, and it cannot again be heated to the same degree by similar means, until it has been exposed in fire, to a red heat. Is it not possible that, by hammering, the particles of iron have been driven closer together, and the latent heat driven out? No further hammering will force the atoms nearer, and therefore no further heat can be developed. But when the iron has again absorbed caloric, by being plunged in a fire, it is again charged with latent heat. Indians produce sparks by rubbing together two pieces of wood. Two pieces of ice may be rubbed together until sufficient warmth is developed to melt them both. The axles of railway carriages frequently become red hot from friction.

Yes; whenever oxygen combines with carbon to form carbonic acid gas, an extrication of heat takes place, however minute the amount. Such a combination occurs much more extensively during the germination of seeds and the impregnation of flowers, than at any other time. In the germination of barley heaped in rooms, previous to being converted into malt, it is well known that a considerable amount of heat is developed.

Yes. It has not only been found that under particular circumstances the heat of certain parts of plants is elevated to a very remarkable degree, but that, under nearly all circumstances, they have a temperature different from that of the external air, being warmer in winter, and cooler in summer.

There are three, viz., slow oxydation, when little or no light is evolved; a more rapid combination, when the heat is so great as to become luminous; and a still more energetic action, when it bursts into flame.

Because it is undergoing slow combustion.

Because they are undergoing slow combustion. In these cases the heat and light evolved are at no one time very considerable. But the total amount of heat, and probably of light, generated through the lengthy period of this slow oxydation, amounts to exactly the same as would be evolved during the most rapid combustion of the same substances.

It is gaseous matter burning at a very high temperature.

Carburetted hydrogen.

Because the lighted paper gives a heat sufficient to ignite the gas; and because also hydrogen requires the contact of flame to ignite it.

Because the carbon of the coals, and the oxygen of the air, have begun to combine, and have greatly increased the heat, and have produced a rapid combustion, so nearly allied to flame, that it ignites the hydrogen.

That depends upon the nature of the combustible you desire to burn. Finely divided phosphorous and phosphorated hydrogen will take fire at a temperature of 60 deg. or 70 deg.; solid phosphorous at 140 deg.; sulphur at 500 deg.; hydrogen and carbonic oxide at 1,000 deg. (red heat); coal gas, ether, turpentine, alcohol, tallow, and wood, at about 2,000 deg. (incipient white heat). When once inflamed they will continue to burn, and will maintain a very high temperature.

Smoke consists of small particles of carbon of hydrogen gas, and other volatile matters, which are driven off by heat and carried up the chimney.

It is, as it might all be burnt up by better management.

By putting on only a little coals at a time, so that the heat of the fire shall be sufficient to consume these volatile matters as they escape.

Because the hydrogen and the volatile parts of the coal have already been driven off and consumed, and the combustion that continues is principally caused by the carbon of the coals, and the oxygen of the air.

It burns brightly, but it produces neither flame nor smoke.

Because the hydrogen has been driven off by the processes by which charcoal and coke are made.

A conductor of heat is any substance through which heat is readily transmitted.

A non-conductor is any substance through which heat will not pass readily.

Gold, silver, copper, platinum, iron, zinc, tin, stone, and all dense solid bodies.

Fur, wool, down, wood, cotton, paper, and all substances of a spongy or porous texture.

By Conduction, Radiation, Reflection, Absorption and Convection.

It is the communication of heat from one body to another by contact. If I lay a penny piece upon the hob, it becomes hot by conduction.

The reflection of heat is the throwing back of its rays towards the direction whence they came. In a Dutch oven the rays of heat pass from the fire to the oven, and are reflected back again by the bright surface of the tin. There is, therefore, considerable economy of heat in ovens, and other cooking utensils constructed upon this plan.

The absorption of heat is the taking of it up by the body to which it is transmitted or conducted. Heat was conveyed to my hand by radiation, and taken up by my hand by absorption.

The convection of heat is the transmission of it through a body or a number of bodies, or particles of bodies, by those substances which first received it; as when hot water rises from the bottom of a kettle and imparts heat to the cold water lying above it.

Because wood is a bad conductor of heat.

Because the arrangement of the particles of which it is composed does not favour the transmission of caloric.

Because some are bad conductors of heat, and do not draw off much of the warmth of our bodies; while others are better conductors, and take up a larger portion of our warmth.

The non-conductor, as it does not readily absorb the warmth of our bodies.

Gold, silver, copper, and most substances of close and hard formation, &c.

Fur, eider down, feathers, raw silk, wood, lamp-black, cotton, soot, charcoal, &c.

Because wood is not so good a conductor as metal, therefore the wood prevents the heat from being transmitted by conduction to our hands.

Because the metal of the coffee-pot would otherwise conduct the heat to the hand; but wood, being a bad conductor, prevents it.

Because metal, being a good conductor, readily delivers heat to the hand; but earthenware, being an indifferent conductor, parts with the heat slowly.

By passing the top of the finger along the wooden handle of the coffee-pot, until it reaches the point where the wood meets the metal. The wooden handle will be found to be cool, but the metal will feel very hot.

Being made of bad conductors, such as wood, paper, or woollen cloth, they will not readily conduct the heat from the kettle to the hand.

Yes. But so slowly that the hand will not feel the inconvenience of too much heat.

Because metal gives out heat more rapidly than wool, by which it is made more perceptible to our feelings.

The wool, because, although the metal conducts heat more rapidly, to a substance in contact with it, it does not radiate heat as well as a black and rough substance.

Because iron is one of the best conductors, and draws off heat from the hand very rapidly.

When we feel cold, heat is being drawn off from our bodies.

When we feel hot, our bodies are absorbing heat from external causes.

The condition here implied is that of health, and of ordinary circumstances. A person in a condition of fever, suffering from intense heat arising from a diseased state of the blood, could not be said to be absorbing heat. Nor could such a description apply to a person who, by a very rapid walk, has raised the temperature of his body considerably above its natural state, by the internal combustion which has already been described. A person feeling hot in bed, from excessive clothes, feels hot from the development of heat internally, which is not conducted away with sufficient rapidity to maintain the natural temperature of the body.

The foot on the stone, because stone is a good conductor, and would conduct the warmth of the foot away from it.

It delivers it to the surrounding air, and to any other bodies with which it may be in contact—and as it parts with heat, it takes up more from any body hotter than itself.

They are all of the same temperature.

Because they differ in their relative powers of conduction. Those that are the best conductors feel coldest, as they convey away the heat of the hand most rapidly.

If you lay your hand upon the woollen table cover, or upon the sleeve of your coat or mantle, it will feel neither warm nor cold, under ordinary circumstances. But if you raise your hand from the table cover, or coat, and lay it on the marble mantel piece, the mantel-piece will feel cold. If now you return your hand from the mantel-piece to the table cover or coat, a sensation of warmth will become distinctly perceptible. This will afford a good conception of the relative powers of conduction of wool and marble.

Until it has brought the part touching it to the same temperature as itself.

When they are of the same temperature as our bodies.

Because they neither take heat from, nor supply it to, the body.

It would feel hotter than the hearth-rug, because it would part with its heat so rapidly that it would be the more perceptible.

Then the hearth-stone would feel the colder, because, being a good conductor, it would take heat from the hand more freely than the hearth-rug, which is a bad conductor.

Because, being a good conductor, it would conduct heat rapidly to the hand when hot, and take heat rapidly from the hand when cold.