The fuels of the household, their origin, composition and uses

Prefatory Note

TN writing this essay I have assumed an audience of -^ young housekeepers and those who are to become such. I have sought the best information on the subject which the abundant professional and bibHographical resources of the National Capitol afford, but I have thought it best to use a style of direct statement rather than one embracing complex statistical forms.

I am especially indebted to my father, Dr. Charles A. White, whose abundant published writings on geological and botanical subjects are well known. He has not only placed his large accumulation of manuscripts at my disposal, but I have constantly had the benefit of his counsel and of his personal recollections of many of the conditions and events of which I have written. m. w.

Contents

PAGB

I. Introduction i

II. Composition of Fuels 5

Chapter I Introduction

THAT the natural resources of light and heat are universal is shown by the energy and diffusion of the sun's rays throughout the solar system, by the intensity of heat in active volcanoes, and by the fierceness of lightning flashes when storms prevail. So small, however, is the draft that man has hitherto been able to make upon those great natural resources for economic uses that nearly all his supplies for those uses are obtained by artificial means.

To a comparatively small extent the sun's rays have been utilized, and under specially favorable conditions light is now abundantly produced by the artificial control of electric currents, and heat for domestic and other economic uses is largely obtained by the same means. The fact still remains that, with exceptions to be mentioned on following pages, the light and heat which are practically used in the household and industrial arts are artificially produced from substances called fuels, by chemical processes which are ordinarily called combustion and incandescence, respectively.

The same kinds of fuels are used, or are usable, in the household that are used in the industrial arts ; and although much the greater part of the fuels which are now utilized by man are consumed in the world's great activities, success in housekeeping is quite as dependent on the skillful selection and management of fuels as it is in the case of great industrial enterprises.

The three principal objects for which our household fuels are used are the warming of our dwellings, the lighting of them, and the cooking of our food. Although it is true that light may be produced with little or no accompanying heat, and that heat may be produced with little or no light, all the fuels which are now used for lighting may be, and in many cases are, used for heating. Therefore the term "fuel" is employed to designate all those combustible substances which are used in our households and in the industrial arts to produce either light or heat, or both. The fuel substances which are to be considered in the following chapters are such as are commonly used in the household, and all of them are obtainable in the fuel markets or from special dealers.

For convenience of reference on following pages, household fuels are divided into solid, semi-solid, liquid, and gaseous fuels. The solid fuels are mineral coals and coke, wood and charcoal, and peat. The semi-solid fuels are wax, fats, resin, stearin, palmitin, spermaceti, and paraffin. The liquid fuels are the oils and alcohols. The gaseous fuels are the natural and artificial gases which are readily combustible, but which are not condensible to a liquid condition except at extremely low temperatures, too low for practical consideration. Fuels are also in part grouped with reference to their origin; as some are of animal origin, some of vegetable origin, and some are derived directly from the earth. The last mentioned fuels are appropriately called mineral fuels, although some, if not all of them, are primarily of vegetable origin.

In discussing these fuels and their uses on following pages, the mental scene of all the processes and utilities which are mentioned is the household. The households of our country are so distinctively American that the subject of this essay is naturally devoted to that type. The historical range of that type is short, because the political history in connection with which it was developed is short compared with that of other countries. And yet, eventful as that short political history has been, the household affairs which have pertained to the use of fuels have been quite as eventful.

For example, there are aged persons now living who were born and reared, not upon the westward moving frontier, but among the settled population of the Eastern states, who, during their childhood and early youth, never ate any food that was not cooked either at the open kitchen fire or in the adjacent brick oven. No castiron ranges, nor even the commonest cook stoves, had then come into use. Neglected fires were rekindled by means of the flint and steel, or, if the tinder box was out of order, one of the children was sent to a neighbor's house to ''borrow fire." A half-burnt brand was taken from the kitchen hearth and swung over the head of the running child to keep it burning. Friction matches were not then invented. The usual household light was that of rude tallow candles, and the best light then available for household use was obtained from whale oil.

This oil deserves special mention because the demand was then so great that ships sailed every sea to obtain it. Mineral oil, except in quantities too small for practical use, was not then known to exist in our country. When that oil was discovered by deep boring, it came in such quantity, and its refined product, kerosene, came so suddenly and abundantly into use, that the whaling business was destroyed, and the ships returned to port empty and rotted at their docks. Illuminating gas from coal had hardly passed its experimental stage, even in the larger cities, and the most prophetic mind among the people never conceived of lights so brilliant and serviceable as those with which our households and public buildings are now furnished. Churches and public halls were not warmed, and in bitter winter weather the whole family gathered around the roaring wood fire upon the great kitchen hearth. No system of general housewarming was then known, and mineral coal was seldom seen except upon the blacksmith's forge. That such revolutions as these could have occurred with relation to the domestic customs of a progressive people within the memory of an individual is marvelous but true, and the half has not been told.

Chapter II Composition Of Fuels

TJECAUSE the foregoing classification, or manner of -*-' grouping, of the fuels is followed in the subsequent chapters, it will be necessary to remember them to have a clear understanding of the statements therein made. It is also quite necessary for one who desires to know fuels to become familiar with the elementary facts pertaining to their composition and their manner of combustion to produce heat and light. It is for the purpose of briefly summarizing those facts that this and the next following chapters are introduced.

The Chemical Elements. Not only the earth and all that pertains to it, including its solid mass as a planet, but its w^aters and all that they contain, its atmosphere and all that pervades it, and all the animal and vegetable forms which dwell or grow upon it, consist of various kinds of matter which are called elements and compounds of elements. Those chemical elements have never been divided into other substances, as the compounds have been, and they are generally regarded as incapable of such division. Their number at present known is above seventy. In density and other properties they vary from ponderous metals, as iron, on the one hand, to invisible gases, some of which are lighter than air, on the other. Very few elements are found free in nature, but are usually combined with other elements. Every such combination produces a substance which is quite unUke any of the elements of which it is composed.

Chemical Reaction. The incHnation which the elements have to unite to form compounds whenever they are brought into intimate contact under such conditions as solution and heat varies so greatly that an element will often leave its associate in a compound and unite with another element. The two freed elements either unite to form another compound, or, in passing off, each unites with other elements. This exchange of association is called chemical reaction, and all known substances are liable to be affected by such reaction. Whatever may be the result of such questions as have lately been raised as to the destructibility or transmutability of elements, such possibilities need not be considered with relation to the elements concerned in fuel combustion. We see and handle those elements in their visible and tangible condition, and, although they become invisible and intangible when their combustion has occurred, we demonstrate that they still exist when we account for the products of combustion.

Sometimes chemical reaction is slow, as in the rusting of iron and in what is ordinarily called decay of animal -and vegetable 'substances. Sometimes it is very rapid, as in the burning of fuels, especially the fierce flames of liquid and gaseous fuels. Sometimes it is explosive, as is seen in the so-called fire tests of the mineral oils, and by the disastrous results of the careless handling of gasoline.

The Fuel Elements. There are only a few of the large number of the chemical elements with which we shall have anything to do in the study of household fuels. Indeed, there are only three of them which take really an active part in the combustion of fuels, namely, carbon, hydrogen, and oxygen; but it will be necessary to mention a few others as accessories to combustion and to ignition, or the kindling of fires. Each of the elements generally assumes a very different condition in every combination which it makes with another element, but such transformations need be mentioned only for those which are immediately concerned in fuel combustion. For example, oxygen, which is so abundant that it is estimated to constitute nearly one-half of the bulk of the earth, exists in a great variety of conditions. It enters largely into the composition of minerals and into the solid part of vegetable matter, where it is necessarily solid. It is a large constituent of water, where it is of course liquid. It constitutes a large part of the atmosphere, where it is closely associated with, but not chemically united to, nitrogen. In that association it is necessarily gaseous, as it always is in its pure state.

The diamond is the purest form of carbon known, and in that condition it is one of the hardest of known substances. Charcoal, coke, and anthracite, although widely different from the diamond, are nearly pure forms of carbon. All the other solid fuels, as well as the semi-solid fuels, are largely composed of carbon, and in these fuels it exists in a more or less solid condition. Carbon also forms a component part of all alcohols and oils, in both of which kinds of fuel it is necessarily liquid. It is an essential component of all the gaseous fuels, and in them it is necessarily gaseous.

Hydrogen in a free state is an inflammable gas, which burns with a bluish flame, and is the lightest substance known. In the gaseous fuels it combines with carbon and still retains its gaseous condition. In combination with oxygen, hydrogen generally assumes the liquid condition, that combination forming water. In all the other liquid fuels of which hydrogen forms a part, it is necessarily liquid. Hydrogen enters into the composition of all the solid and semi-solid fuels, with the exception of pure anthracite, coke, and charcoal. In these fuels it is necessarily in a correspondingly solid condition.

Accessory Fuel Elements. It is desirable to mention a few other elements which enable us to get a more complete view of the nature of combustion. Nitrogen should be specially mentioned in this connection, although it is wholly inert in the process of fuel combustion. It is very abundant everywhere, associated with oxygen in the atmosphere, and when freed from that association by fire it accompanies the products of combustion and goes unchanged to take its former place in the atmosphere. In its pure state nitrogen is a colorless gas, but like other gaseous elements it becomes a solid by some of the combinations which it makes with other elements. Such an example is seen in the well-known saltpeter, or nitrate of potash, which is mentioned among the kindling materials in a following chapter because it is combustible, although not a fuel.

It is proper to mention here that within a few years three other gaseous elements have been discovered in the atmosphere. They are rare, or little known, but in fuel combustion they seem to hold the same position with relation to the fuel elements that nitrogen does, that is, entire inertness. The names which have been given to these elements are argon, helium, and neon, respectively. The Importance of Carbon and Hydrogen. In the next chapter statements are made concerning the process of combustion of the different kinds of fuel which show the great importance of oxygen in all those processes ; and yet they show that oxygen is not itself a fuel. The only true fuel elements arc hydrogen and carbon; but there can be no combustion of those elements without oxygen. Being indispensable, it is fortunate that oxygen is always and everywhere at hand, free of expense and requiring no labor for its preparation and storage. On the other hand, hydrogen and carbon must be obtained by great labor and at great expense.

Chapter III Combustion, Ignition And Incandescence

OXIDATION. Oxygen, which is ever present in the atmosphere, has a constant tendency to unite chemically with most of the other elements. Consequently it readily leaves its associate, nitrogen, to unite with them, that being the act of oxidation w^hich is to be so often mentioned in the following remarks. Fuels exposed to the air are all attacked by oxygen and undergo a very slow process of oxidation at ordinary temperatures, and without fire. This open-air oxidation is hardly perceptible, even after long exposure, in the case of the hardest of the solid fuels, but it always exists, and differs from burning by fire only in the length of time in which it is accomplished. Even the amount of heat which is given off in the process is the same in both cases, because, as is well known to chemists, the amount of heat which is given off by oxidation is always in proportion to the extent of that process. In the case of open-air oxidation of fuels, heat is given off too slowly to be perceptible to the senses, but so rapidly in the case of their ignition that combustion results.

Combustion. If fuels are placed in suitable receptacles and fire is applied to them, they also take fire and are more or less quickly consumed. This process is combustion, the well-known burning of fuel, in which, instead

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of the exceedingly slow rate of open-air oxidation, there is a violent and rapid oxidation which quickly converts the fuel into what are called the products of combustion.

With the exception of anthracite, coke, and charcoal, all solid fuels contain enough hydrogen to give off more or less flame. When either of those three fuels burn, there is only carbon combustion, and the fire consists of a bed of embers. Hydrogen is often called the greedy element because it will unite with oxygen more readily than any of the others ; so when hydrogen is contained in any of the solid fuels it is more readily ignited than is the carbon. After the burning of the hydrogen has ceased, the carbon combustion proceeds alone, forming, as in the other case, a bed of embers which, when exhausted, leave only the ashes. The manner of combustion of the flame fuels will be discussed further on.

Products of Combustion. The products of combustion are, properly speaking, only those invisible gases and vapors which pass off in the upward current that heat causes to rise from the burning fuel. That term does not include smoke, soot, or ashes, but they ought to be briefly referred to in this connection.

Smoke consists largely of finely divided carbon which has been partially oxidized in the fire but not consumed, and, in company with more or less watery vapor, escapes from the fire by the upward draft. Smoke represents wasted fuel ; the denser the smoke the more fuel is wasted. The very light-colored smoke which one often sees escaping from chimneys consists largely of watery vapor.

In the burning of wood and some of the softer coals, a part of the oily compounds which are included with the hydrocarbons are volatiHzed, escape full oxidation, combine with fine, escaping particles of free carbon, adhere to the inner walls of the chimney flue, and constitute chimney soot. The soot from wood fires is also impregnated with creosote.

Wood ashes consist of certain mineral substances which the growing tree takes from the earth dissolved in its food-sap, together with such accidental impurities as become embodied in, or mingled with, them during the growth of the tree, or afterward. Coal and peat ashes often contain mineral materials which have accumulated while those fuels were forming. Certain of the mineral substances which are contained in the coal ashes are often fused by the fire into lumps which become hard on cooling, and are commonly called clinkers. Excess of ashes, and especially of clinkers, which sometimes occurs in coal ashes, "retards combustion by obstructing the under draft. Hard wood ashes contain much potash, which was formerly the chief reliance for making the family soap. Ashes of the pines and of the other conifers contain very little potash, and coal ashes contain no appreciable amount of it.

The chief products of combustion proper are carbon dioxide and carbon monoxide, and, when the fuel contains hydrogen, water is produced as steam. It should be remembered that steam is invisible. What we generally call steam is really watery vapor, or steam in the process of condensation. The two products first named originate in fuel combustion as invisible gaseous compounds that are formed by the chemical union of oxygen from the air and the carbon of the fuel. When two

HOUSEHOLD FUELS I3

parts of oxygen unite with one part of carbon, the gas, carbon dioxide, is formed. This gas is heavier than air at ordinary temperatures, but, heated by the fire in which it originates, its relative weight is decreased and it rapidly rises with the upward current, which also mechanically assists it to rise. Carbon dioxide is not only incombustible, but it will extinguish fire as quickly as will water if allowed to cover it. The union of one part of carbon with one part of oxygen produces the gas, carbon monoxide, which is often seen burning with a slight bluish flame over smoldering fires of both coal and wood. It is a product of incomplete combustion, while carbon dioxide is a product of complete combustion, the carbon in the latter case having united with all the oxygen of which it is capable. Both of these gases, particularly the carbon monoxide, are fatally poisonous if freely inhaled.

Water has been proved to exist in the products of combustion of certain fuels which, before their combustion, were known to contain neither oxygen nor water, but to contain hydrogen. This water, therefore, must have been specially formed during the combustion by oxygen from the air uniting with hydrogen of the fuel. Such water passes off in the form of steam, and finally as vapor, together with other vapors, accessories, and products of combustion, as does water which has been incidentally added to the fuel.

Although carbon dioxide and carbon monoxide are the chief products of combustion, there are always accessory gases and volatile products which also pass upward in the current that rises from the fire. These have just been in part referred to, but summarily stated they are, first, the nitrogen with which its atmospheric associate, oxygen, has parted to take the leading part in combustion; second, water, which the fuel may have acquired before burning; and third, impurities in the air w^hich is supplied to the burning fuel. There may also be some water originating as was described in the next preceding paragraph.

All the solid fuels, hardly excepting the densest mineral coals, so readily absorb water from the earth and atmosphere that some water in the form of vapor accompanies the products of their combustion, as well as the accompanying gases, which are invisible, and therefore give one the feeling that they have been totally destroyed. The fuel, as such, has been destroyed, but each of the elements of which it was composed has only changed from one of its conditions to another.

Without doubt, also, the three rare, lately discovered, gaseous elements which are named in the preceding chapter, argon, helium, and neon, accompany every upward current of fuel combustion. There is something impressive in the subjection of those four quiescent elements to that fiery passage in a process in which they have no part, and whose destination is the same condition as that from which they were taken. They at least emphasize the aggressive action of the oxygen and the greediness of the hydrogen and carbon.

Ignition. Because the slow process of oxidation which all fuels undergo from exposure to the atmosphere differs from combustion only in the slower rate of its progress, it needs only the addition of fire to start the faster rate, which is called combustion. This initial application of fire to produce fuel combustion is known technically as ignition, but in the household it is known as kindling. No matter how freely fuels will burn under favoring conditions, ignition of all of them must be begun either by fires already produced, or by the production of a small quantity of burning heat that may be communicated by intermediate means to the fuel. There is a large number of materials which have been, or which may be, thus used for the lighting of fires, but the friction match now in use is the most convenient and effective of them all. In the following paragraphs some of the other materials and various methods of employing them are, however, mentioned to show how earnestly man has sought out methods of replenishing his fires. They also show what is more to the point for our present purpose, that fires may be produced by widely different methods. A very laborious, but a simple and direct primitive method of kindling fires is by rubbing two narrow and perfectly dry pieces of readily combustible wood together, sometimes by holding the pieces at right angles to each other, and sometimes by holding them both in the same direction. Another primitive method of kindling by wood friction is that of rapidly twirling a dry pointed stick in a piece of wood of the same kind, which has been slightly hollowed. In all three of these cases the fine particles of wood which are detached by the friction take fire from the heat which is also produced by it. In these cases ignition of the wood is accomplished without the aid of any other material. All three of these methods are very ancient, and their use lingers only where friction matches are difficult to obtain, or where the production of fire has been part of a religious ceremony.

A method of fire kindling which has long been known, and which even now is practiced by many savage and semi-civilized peoples, is known as that of the fire piston. This instrument consists of a small cylinder of horn, bone, or metal, a few inches in length, less than an inch in diameter, and having a central bore. The bore is closed at the lower end, but open at the upper end, and is usually less than half an inch in diameter. The piston is made of the same, or a similar, kind of material as the cylinder, but longer, and fits the bore closely. A piece of tinder is dropped into the cylinder and rests upon the bottom. The piston is thrust into the bore only so far as to steady it, and then struck a smart blow upon its upper end. The descent of the piston compresses the air in the cylinder so much and so quickly that it is made hot enough to set the tinder on fire.

Up to one hundred years ago it was not uncommon among our people to keep a ''sun glass," w^hicli was a common lens of a couple of inches in diameter, for practical use in kindling fires. It was not difficult to start a fire by concentrating the sun's rays with such a lens, but the frequent absence of sufficiently bright sunshine at the time fire was needed made that method of little practical use.

The kindling of fire by means of the flint and steel was perhaps the most widely used of the methods which were practiced before the invention of friction matches. This process is very ancient, and iron pyrite probably preceded steel in producing the sparks by the flint stroke. It is even now retained by some savage peoples in regions where that mineral is frequently found. When the edge

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of a flake of flint is struck obliquely upon a small bar of hardened steel, minute bits of the steel are torn off and heated burning hot by the friction of the stroke and the ready action of the oxygen of the air. These brilliant sparks are intensely hot, but they are so small that their heat is quickly lost, and they would therefore be useless if they were not made to fall upon some easily ignited material. Such material is called tinder, and may be of various kinds.

The kind of tinder which was most commonly used in our colonial households and in those of still later date was made by the charring of pieces of cotton or linen cloth, which process changed the cloth to fibrous charcoal. The delicate fibers of this charcoal tinder instantly catch the hot sparks as they fall from the steel, and produce little burrowing patches of sparks of their own among the threads. Rural housekeepers also occasionally used other substances for tinder, among which was a fibrous kind of decayed wood mingled with a fungous growth, and called ''spunk" or ''punk." Hunters and travelers sometimes used still other kinds of tinder, but the charred cloth was superior to all other kinds, and the tinder box in which it was kept was one of the chief household conveniences.

With great care it is possible to ignite fine wood kindlings directly from the burning tinder, but usually the amount of fire which is produced in tinder is too small for such ignition, and an intermediary substance for the transfer of the fire is necessary. For this purpose the sulphur match was used. It was generally known as the "brimstone match," and was also made in the household.

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Sulphur is a distinct chemical element, but, although combustible, it is not a fuel. It melts at a comparatively low temperature, ignites from a spark if only a minute quantity is applied, and burns with a bluish, smoky flame. The match was a slender piece of soft wood, one end of which was narrowed nearly to a point and dipped in melted sulphur. The latter was therefore called the dip, a term which has been continued in use for the corresponding application to friction matches. The small prepared end of the suphur match was applied to the sparks among the tinder, and it quickly became ignited. The sulphur flame at once set the hydrogen of the match aflame, which was then ready to be applied to the candle, lamp, or kindling wood, as we now apply the common friction match.

Early in the nineteenth century a dip was invented which would ignite when the prepared end of the match w^as thrust into sulphuric acid contained in a small bottle, and quickly withdrawn. That method was not of convenient use, and the invention was soon followed by that of a dip which would ignite by friction.

Friction Matches. Several partial successes in the manufacture of friction matches were made before the practical success of the one which was really the direct lineal descendant of the brimstone match. That is, the first really successful friction matches that came into general use were common sulphur matches, each of which had received a second coating of another kind of dip over its sulphur end, which would ignite by friction on a moderately rough surface. Alatches of this simple kind are still in use in some parts of our country.

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Many modifications of that primitive frictional dip have been made, with the purpose of abandoning the use of unwholesome or dangerous materials which it contained, besides others since used. Among the substances that have been used in the preparation of the dip are sulphur, phosphorus, mercury, antimony, and the nitrates of potassium and sodium, besides adhesive and other ingredients. The evil effects of some of these substances upon the health of those persons who are employed in the match manufacture are so great that eft'ort has been made to enforce their abandonment.

The invention of the so-called safety match has much diminished the danger attending the general use of friction matches, and has at least partially lessened that which has long attended their manufacture. The dip on these matches consists of a mixture that only with great difficulty can be made to ignite by friction upon any surface except those which have a specially prepared substance spread upon them. Ignition of the dip material of these matches is caused by chemical reaction between the contents of the dip and those of the surface preparation, which must be incited by friction. In the case of the common friction match, friction alone produces enough heat to ignite the dip material ; but in the case of the safety match, although friction is necessary, the character of the dip is such that it will not ignite without the aid of an accessory substance. Because matches are so generally used and so constantly within the reach . of every one, even of children, it is evident that some such regulation as prevails with reference to kerosene should restrict the use of matches to some safety form. Every housekeeper should insist on having no other kind in the household.