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 o V 
 
 
CHEMISTRY FOE 
 LAUNDERERS 
 
 ALSO FOR 
 
 CLEANERS AND DYERS 
 
 BY 
 
 C. F. TOWNSEND, F.C.S. 
 
 Late Assistant Examiner, Royal College of Physicians, and 
 
 Editor of "The Power Laundry." 
 
 London, Eng. 
 
 ILLUSTRATED 
 
 AMERICAN EDITION 
 
 Published by 
 
 NATIONAL LAUNDEY JOUENAL, 
 
 CHICAGO. 
 
^ 
 
 A 
 
 c\ 
 
 "h 
 
 <S 
 
 <A 
 
 Copyright, 1910 
 
 BY 
 
 DOWST BROS. COMPANY 
 CHICAGO 
 
 
 CG!.A-.'6S071 
 
AMERICAN EDITION. 
 
 This American edition contains all the matter 
 that the original English publication does, cor- 
 rected slightly in spelling, etc., to harmonize with 
 customs of America. Some slight errors which, 
 in the original edition were corrected on one of 
 the last pages thereof, have been corrected in 
 the text, in this edition; and furthermore, some 
 little additional matter has been inserted by the 
 author, bringing the book more up to date. The 
 whole work has been carefully edited by the 
 American publishers, and it is confidently hoped 
 that the book will meet with the reception it 
 deserves, on this side the Atlantic, and elsewhere 
 about the globe, where readers of the National 
 Laundry Journal, are located. 
 
 DowsT Bros. Co., Publishers, 
 National Laundry Journal. 
 
CONTENTS. 
 
 (See Also FuU Index, 183 to 189) 
 CHAPTER PAGE 
 
 I. Inteoduction 7 
 
 II. Chemical Architecture 23 
 
 III. Alkalies 39 
 
 IV. Acids 42 
 
 V. Soaps 49 
 
 VI. Bleaching 67 
 
 VII, Stains, AND Their Removal 79 
 
 Ylll. Solvents 91 
 
 IX. Starches and Other Stiffening Agents. 99 
 
 X. Fuel 117 
 
 XI. Fabrics 135 
 
 XII. Dyes and Dyeing 134 
 
 XIII. Water 145 
 
 XIV. The Chemistry of the Washroom 151 
 
 XV. Some Simple Analytical Work 162 
 
 Appendix A 179 
 
 Appendix B 179 
 
 Appendix C 180 
 
CHEMISTRY FOB LAUNDEREES 
 
 ALSO FOB 
 
 CLEANERS AND DYERS 
 
 CHAPTEE I 
 
 Introduction 
 
 While it is impossible, or next to it, for every 
 launderer to be a chemist, there is no reason what- 
 ever why he should not learn many valuable 
 scraps of chemistry which will come in useful, 
 not merely some time or other, but very frequently 
 in his business. No doubt the time will come, and 
 let us hope it is not very far off, when every laun- 
 derer will have had a good chemical and engineer- 
 ing training. But that is not yet; and although 
 one or two launderers may have found the time 
 and energy to make a serious study of chemistry 
 they are so few and far between as to be hardly 
 worth considering. The average launderer has 
 started with little technical knowledge, and what 
 he does possess has been gained in the hard school 
 of experience and paid for on the high scale of 
 fees that are in vogue in that school. It is not 
 as a rule until he has got over his initial difficulties 
 and settled down into a nice comfortable paying 
 
 7 
 
8 INTRODUCTION 
 
 business that he can spare sufficient time from the 
 pressing worries of everyday routine to devote to 
 anything else, however useful it might prove to 
 him theoretically. By the time he is able to tear 
 himself away from his business to this extent, he 
 naturally feels that he has earned a long rest and 
 is usually not at all inclined to take up the study 
 of chemistry or anything else. Of course, there 
 are exceptions ; but that is the rule. Nevertheless 
 there is no excuse for the launderer not giving 
 his son who is to succeed him in the management 
 of the business the opportunity of learning chem- 
 istry and engineering thoroughly, although for 
 himself this may generally have been out of the 
 question. 
 
 The serious study of chemistry requires several 
 years of almost devoted attention in order to 
 become even comparatively proficient in the sub- 
 ject, especially in analytical chemistry, which in 
 its higher branches is almost an art or a science. 
 Taking all this into account, however, there is no 
 reason whatever why he should not pick up useful 
 scraps of chemical knowledge as he does engineer- 
 ing knowledge; and even something more, pro- 
 vided always that he bears in mind the fact that 
 they are only scraps and takes care not to fall 
 into the many traps that stand in the path of the 
 man with the little knowledge, proverbially such a 
 dangerous thing. 
 
INTEODUCTION 
 
 Apparatus. 
 
 The first thing that stands in the way of the 
 beginner who has not attended chemistry classes 
 — and perhaps qnite as much in the way of those 
 who have — is the question of apparatus. He asks 
 himself ''Must I buy a whole outfit of apparatus 
 before I can make use of the instruction pro- 
 vided?" To which I reply "No! There is very 
 little you need buy; at all events at first." There 
 are very few chemical experiments the launderer 
 is likely to require which cannot be performed in 
 an ordinary gallipot — provided it is clean. While 
 it must be remembered that accuracy down to 
 the minutest detail, and scrupulous cleanliness 
 are the first essentials to any kind of practical 
 chemical, or, in fact, any kind of scientific work, 
 it must not be forgotten that all the early and 
 most of the momentous experiments were con- 
 ducted with home-made apparatus of what we 
 should now consider the crudest description; and 
 considering the difficulties, the results obtained 
 were surprisingly accurate. Consequently, when- 
 ever it is necessary to buy anything more compli- 
 cated than a jam pot I will duly advise the reader 
 of the fact. The only time the launderer will 
 require anything in the nature of accurate chem- 
 ical apparatus will be when he may wish to carry 
 out any quantitative analytical work. And 
 although I do not recommend him to go very far in 
 
10 INTRODUCTION 
 
 this direction without very much more thorough 
 instruction than he can obtain from this little text 
 book, or, for a matter of that, any other, there 
 are certainly some simple analytical operations 
 he might very well undertake, such as the rough 
 valuation of samples of soap, tests for the hard- 
 ness of water and so forth. When I come to this 
 stage I will deal more fully with the apparatus 
 which will be required. 
 
 Temperature. 
 
 In applying chemistry in the laundry, at is 
 always of the first importance to remember that 
 the people who have to do the practical work of 
 the washroom and the starchroom are ordinary 
 uneducated working people who will be pretty 
 certain to make a painful mess of any complicated 
 system, especially as they do not imder stand, in 
 999 cases out of a 1,000, the reasons for what 
 they are doing. Consequently, while the manager 
 should make full use of whatever knowledge he 
 himself possesses, he should, when it comes to 
 operations with which other people have to deal, 
 get them down to the simplest basis. There is, 
 however, one thing in which strict accuracy should 
 be enjoined, and that is temperature. A ther- 
 mometer, although it need not be used with every 
 load of clothes that is washed, should occupy a 
 conspicuous place in every washhouse. Tempera- 
 
INTRODUCTION H 
 
 ture plays a very important part in nearly all 
 chemical operations and most laundry operations 
 are really chemical ones — and if the reader once 
 understands that to get the best results it is neces- 
 sary to work at the proper temperature for that 
 operation, and no other, he will find that he will 
 get on very much better. It may seem strange 
 that I should insist so strongly on this question 
 of temperature, and of buying a thermometer, but 
 as I shall explain directly and frequently later on, 
 the importance of this is very great. Many 
 readers will say, ''Of course I have a thermome- 
 ter!" But there is no of course about it. A little 
 while ago I had a letter from a querist asking 
 whether there was not some instrument like a 
 hydrometer by which she could tell whether the 
 water was the right heat for flannels ! 
 
 Effects of Heat. 
 
 Owing to its importance it would be well if I 
 were to say a little more about this. Most chem- 
 ical operations — or re-actions, as scientific people 
 call them — will only go on at certain temperatures 
 and under certain conditions. An alteration in the 
 temperature or conditions may not only stop 
 the re-action, but even reverse it. Chalk for 
 instance, when strongly heated in a kiln, parts 
 with its carbonic acid and becomes converted into 
 lime. If, however, this lime is exposed to the air 
 
12 INTRODUCTION 
 
 at the ordinary temperature, the action is reversed 
 and it gradually becomes converted back again 
 into chalk. This is only one instance out of a 
 very large number, and while the launderer has 
 not to deal with such extremes as the difference 
 between the ordinary temperature of the air and 
 that of a lime kiln, yet this question of tempera- 
 ture concerns him very intimately. 
 
 One of the kinds of "dirt" which he has to 
 remove from the fabrics entrusted to his care con- 
 sists of exudations from the skin, particles of skin 
 itself and various other animal matters attached 
 to the fibres. All these contain albumin or sub- 
 stances resembling it. Now albumin is rendered 
 insoluble by heating it to a comparatively low 
 temperature, so that the first operation in wash- 
 ing should always be to soak the garments in tepid 
 water containing weak alkali, which assists in 
 loosening the animal matter. Further, the fibre 
 of flannel and woolen goods generally felts 
 together at a high temperature, and chemical 
 changes take place in it, so that it is most impor- 
 tant that the temperature of the water in which 
 flannels are washed should be kept as low as 
 possible. The question of boiling linen and cotton 
 goods is again worth considering. 
 
 The subject of starching is another important 
 one in connection with changes of temperature, 
 and I do not think this question has been nearly 
 
INTRODUCTION 13 
 
 sufficiently studied by launderers. The tempera- 
 ture at which starch is dried before ironing is cer- 
 tainly a very important matter. 
 
 Cause and Effect. 
 
 One of the first things to learn in studying 
 chemistry is that the same causes always produce 
 the same effects, so that if you can once find out 
 the exact conditions for securing the result you 
 wish to obtain, you can always make sure of your 
 result by employing like conditions. With this 
 fact staring him in the face the launderer should 
 have no excuse for allowing happy-go-lucky, rule 
 of thumb conditions to rule in his washroom any 
 longer. If you do not get the right result, be sure 
 there is something wrong with your conditions, 
 and do not rest until you have found out what is 
 wrong and have put it right. Every launderer 
 who has made even a moderate success of his 
 business, knows that this success has been made 
 by introducing and maintaining a rigid system in 
 dealing with the various articles as they pass 
 through the different departments. If he would 
 introduce a similar rigid system into his wash- 
 room as regards the materials employed and the 
 temperatures at which they are employed, he 
 would soon find a marked improvement in the 
 quality of the work turned out. The average 
 washman is much too fond of using a piece 
 
14 INTRODUCTION 
 
 ''the size of a lump of chalk" instead of an accu- 
 rately weighed or measured quantity, and this 
 tendency is nearly always in need of restraint. 
 
 Scientific methods. 
 
 One of the first things to be done towards reor- 
 ganizing the washroom on proper scientific lines 
 is to keep a careful control of the stockroom. 
 Never allow any form of either soap or alkali to 
 be used in its crude state, but make up stock solu- 
 tions and keep them in tanks in or adjacent to 
 the washroom. Neither soap nor alkali should 
 ever be thrown into the washing machine in the 
 solid state as I have sometimes seen done. It 
 destroys the goods and wastes the materials. Give 
 distinct instructions as to the quantities to be 
 employed, and make an occasional calculation to 
 insure these quantities are not greatly departed 
 from. 
 
 Another thing to be done in the way of insuring 
 scientific accuracy, is to measure each machine 
 and record the amount of liquor used in the wash 
 and the approximate amount of soap and soda 
 required for washing the different classes of arti- 
 cles. This should be posted up at the back of the 
 machine for permanent reference. 
 
 All this talk about weighing and measuring may 
 perhaps seem a little foreign to the subject in 
 hand, but science has been defined as accurate 
 
INTEODUCTION 15 
 
 measurement, and the first thing a student has to 
 learn when he comes into a chemical, or any other 
 scientific laboratory, is to weigh and measure with 
 scrupulous exactitude. If the launderer learns 
 nothing else from this book but to measure accu- 
 rately all the materials and temperatures he uses 
 in his washroom and starchroom he will have 
 learned something of the greatest value. 
 
 The Nature of Things. 
 
 Like so many things in this world, material 
 objects such as soap, soda, the fabrics which pass 
 through the launderer 's hands, in fact, everything 
 that he can see and touch, are not so solid as they 
 look. They are composed of very minute particles 
 — so minute that you could not see them under 
 the most powerful microscope — and these particles 
 are separated from one another by quite apprecia- 
 ble distances — appreciable, that is to say, com- 
 pared with the size of the particles themselves. 
 The particles are always in a state of motion, the 
 extent of the motion depending upon the tem- 
 perature — the higher the temperature the more 
 rapid the motion; consequently chemical changes 
 take place much more rapidly as the temperature 
 goes up. Even solid particles which are not too 
 small to be seen under a microscope are in a state 
 of rapid oscillatory motion; that is to say, 
 although they do not move away from their posi- 
 
16 INTRODUCTION 
 
 tion they swing backwards and forwards like tiny 
 penduhuns, only mucli more rapidly than the pen- 
 dulum of a clock. This motion can be observed 
 quite easily by rubbing down a little gamboge, or 
 some other finely-divided solid in water and plac- 
 ing a drop under the microscope. This state of 
 motion of finely-divided particles has an import- 
 ance for the launderer, for it is on account of 
 this that the cleansing of linen with water is a 
 comparatively easy matter. 
 
 Surface Action. 
 
 There are certain other properties of matter 
 that I must deal with before going farther, as they 
 have an important bearing on laundering opera- 
 tions, as well as on cleaning and dyeing. There 
 are probably few of my readers who have not 
 noticed that water and some other liquids have 
 a tendency to creep up the sides of a glass vessel 
 in which they are contained. In a wide vessel 
 this is not so very easy to see, but in a narrow 
 one it is very noticeable. In such a narrow tube 
 as is employed for thermometers, the water rises 
 in the interior quite an appreciable distance above 
 the level of the rest of the liquid if an open tube 
 of this description is placed in water. If, however, 
 a similar tube be placed in mercury, exactly the 
 opposite effect is noticed ; the mercury in the tube 
 is depressed below the level of the rest of the 
 
INTRODUCTION 17 
 
 liquid. In coloquial language, the water '*wets" 
 the glass, while the mercury does not. The former 
 is attracted to the glass ; while the latter is repelled 
 from it. A greasy surface has exactly the same 
 effect on water as the glass has on mercury — the 
 water is repelled from the grease and consequently 
 has no cleansing action on greasy fabrics if used 
 alone. Soap and alkali, especially the former, 
 quite apart from their specific action on the 
 grease, greatly increase the tendency of water to 
 "wet" things, and that is one of the reasons why 
 they are so useful to the launderer. Another rea- 
 son why soap is so valuable is that it greatly stim- 
 ulates the movement of the solid particles referred 
 to above and consequently enables the water to 
 remove the dirt from the fabric by mechanical 
 action. 
 
 Capillary Action. 
 
 There is another matter depending upon this: 
 I referred just now to the tendency of water and 
 certain other liquids, to creep up narrow tubes; 
 well, all fabrics, or nearly all, consist of tiny 
 tubular fibres, woven or felted together, and water 
 has the power of creeping up these tiny tubes for 
 quite a long way. If the water contains a dye, 
 this is carried up. with the water and deposited in 
 the fabric. 
 
18 INTRODUCTION 
 
 Diflfusion. 
 
 Yet another property of matter. If you divide 
 a vessel in half by a vertical porous partition and 
 place plain water on one side and water containing 
 a dye on the other, you will find that although 
 the liquids are exactly the same height on both 
 sides of the partition and are kept apparently 
 absolutely still, the coloring matter will travel or 
 *' diffuse" from one part to the other until there 
 is the same amount of dye in all parts of the 
 liquid. Even if by mechanical means you could 
 put the heavier liquid containing the dye or any 
 other soluble salts, such as soda, at the bottom of 
 the vessel and the plain water on the top, you 
 would find the same thing would happen. This 
 is what happens when a washman by an unfor- 
 tunate accident puts a red sock in with a load 
 of whites, as probably many of my readers know 
 to their cost. This property of diffusion is one 
 of the reasons why we are able to dye goods at all. 
 
 Diffusion is not confined to liquids, but occurs 
 even in the case of some apparent solids; while 
 in gases, such as the air we breathe or the coal 
 gas we burn, diffusion is far more active than in 
 the case of liquids. Everyone knows how rapidly 
 an escape of gas will make its presence felt, not 
 only in the immediate neighborhood of the escape, 
 but all over the building. This is due partly to 
 
INTRODUCTION 10, 
 
 the currents of air, but also to diffusion.. It is 
 the same property of diffusion which causes coal 
 gas to escape through the pores of an india-rubber 
 tube. 
 
 Conduction and Connection of Heat. 
 
 Now, here is another point: Has it ever 
 occurred to any of my readers to consider why 
 they apply heat to a vessel at the bottom instead of 
 at the top! The reason is that water is a very 
 poor conductor of heat, and by means of suitable 
 arrangements for heating a vessel at the top it is 
 quite possible to have boiling water at the top of 
 the vessel and a piece of ice at the bottom. In 
 addition to water being a bad conductor, hot water 
 is much lighter than cold water, so that in the 
 experiment referred to the hot water being at the 
 top stays there and is very little affected by the 
 heavier cold water underneath. The Gulf Stream 
 forms an excellent example of this ; here you have 
 a river of warm water running for hundreds of 
 miles on the top of cold water and hardly mixing 
 with it. When you apply heat at the bottom of a 
 vessel the heated water being lighter, rises to the 
 top through the middle of the liquid, while the 
 heavier, cold water pours down the sides to adjust 
 the balance, and a constant circulation is set up, so 
 that the water is heated evenly throughout. This 
 has a very practical application for the launderer 
 
20 INTRODUCTION 
 
 in the ease of boilers. In a badly constructed 
 boiler or one in wliicli scale is heavily deposited in 
 some parts, it is quite possible for there to be 
 quite large differences in the temperature of the 
 water in the different parts of the boiler. Conse- 
 quently an enormous strain is set up, which causes 
 leakages and rapid deterioration of the shell. 
 
 Radiation, Reflection and Conduction. 
 
 While upon this subject I will explain the differ- 
 ence between radiation, reflection, and conduction 
 of heat. Every launderer probably knows the 
 different effect of opening a steam valve with a 
 bright gun metal wheel and one of iron painted 
 over. In the first place it will be so hot he can 
 hardly touch it; while in the latter he can turn 
 the valve without any inconvenience. The reason 
 is that the heat from the steam in the pipe flows 
 much more easily along the copper than along 
 the iron and especially along the paint ; that is to 
 say, copper is a much better conductor of heat 
 than iron. Again, if the hand be held close to a 
 bright copper vessel on a cooking stove a much 
 smaller sensation of heat will be felt than if it be 
 held at the same distance from a black iron one; 
 the heat radiated from the latter being much 
 greater. The rule is that substances which are 
 good reflectors, such as bright copper or white 
 paint, are bad radiators. Consequently steam and 
 
INTRODUCTION 21 
 
 hot water pipes should always be painted white or 
 covered with that new metallic paint. 
 
 Light. 
 
 Light again cannot be left out of account in the 
 introduction to notes on chemistry. In the first 
 place it will be found that many chemical sub- 
 stances if placed in the light undergo important 
 changes, which render them unfit for the purpose 
 for which they were intended. Hydrogen per- 
 oxide, for example, decomposes rapidly if exposed 
 to bright light, and everyone is familiar with the 
 strong effect of sunlight upon moist linen hung 
 out of doors; the effect of sunlight on fugitive 
 dyes is even better known. Light is a particular 
 form of force which is transmitted from a lumin- 
 ous body like waves traveling over the surface of 
 the sea and certain kinds of light waves produce 
 curious chemical effects in many substances. As 
 already partly explained matter consists of tiny 
 particles separated from one another by compara- 
 tively appreciable distances, and these light waves 
 have the power of making some of these particles 
 vibrate in time with themselves, just as the bricks 
 of which a church is built will rock or vibrate in 
 response to the sound waves from the large pipes 
 of an organ. In the case of the light waves I 
 have just been considering, the rocking or vibra- 
 tion of the particles under the influence of the 
 
22 INTRODUCTION 
 
 waves of light often becomes so great that the 
 complicated chemical compound falls to pieces and 
 becomes something simpler. This is what hap- 
 pens in the case of a fugitive dye exposed to the 
 sunlight, or of a piece of stained linen hung out 
 in the open air. 
 
CHAPTER II 
 
 Chemical Architecture 
 
 Before going any farther it will be necessary to 
 say some more about the tiny particles of wliich 
 material substances are made up, as the chemical 
 nature of a body depends quite as much upon the 
 way these particles are arranged as upon the 
 differences in the nature of the particles them- 
 selves. When a metallic casting or forging is 
 made, the particles are set in certain directions 
 which in the relation of the particles to one 
 another gives the metal sufficient strength to bear 
 the strains put upon it. If, however, it be sub- 
 jected to continuous vibration, such as a railway 
 car gets in traveling at a high speed over the 
 metals, or if the material be continually heated 
 and cooled, as happens to the metal forming the 
 bed of an ironing machine, the vibration causes 
 the particles to set themselves all in the same 
 direction and a large proportion of the strength of 
 the material is lost; consequently it becomes 
 unable to bear the strain, and some fine day, with- 
 out any warning, the railway car axle or the bed 
 of the ironing machine gives way. This property 
 
 23 
 
24 CHEMICAL ARCHITECTTJEE 
 
 of metals to get ''tired" so to speak, is well known 
 to engineers, and is spoken of as the "fatigue" of 
 metals. This peculiarity is very noticeable in 
 working metals, such as hammering copper or 
 drawing wire; after a short time the metal 
 becomes brittle and has to be reheated or 
 ''annealed" before the work can proceed. In 
 making a casting, there is always an outer "skin" 
 to the metal, which possesses much greater tensile 
 strength than the body of the metal inside, so that 
 if, for example, some of the surface be planed off 
 a calender bed to make it fit the roller better, the 
 bed is appreciably weakened, not because of the 
 comparatively small amount of metal that is re- 
 moved, but because the "skin" — the strongest 
 part — has been planed off. These are only a few 
 instances, and many more might be given if space 
 permitted. 
 
 The Composition of Water. 
 
 Now for something about the chemical proper- 
 ties of the particles. It is convenient to commence 
 with the study of water, because it is one of the 
 commonest substances, and make a good starting 
 point into the bargain. If we pass an electric cur- 
 rent through a liquid it apparently causes the 
 particles composing the liquid to move, half of 
 them with the current, and the other half against 
 the current, so that at the terminals, that is to say, 
 
CHEMICAL ARCHITECTUKE 25 
 
 where the current enters and leaves the liquid, the 
 particles are given off in the free state. In the 
 case of water, we shall find if we try the experi- 
 ment, that bubbles of gas are given off from each 
 terminal plate, and if we collect the bubbles we 
 shall find that twice as much gas is given off from 
 the negative plate, that is to say, where the cur- 
 rent leaves the liquid, as from the positive plate, 
 where the current enters. We shall find also that 
 the gas given off at the negative end will burn 
 with a blue flame; while that given off from the 
 other end will cause a glowing match to burst into ^ 
 flame. The former gas is known as hydrogen, and 
 the latter as oxygen. We have seen that there are 
 two volumes or two particles of hydrogen given 
 off for every one of oxygen; consequently a par- 
 ticle of water appears to be made up of two par- 
 ticles or atoms of hydrogen and one of oxygen ; or, 
 to put it graphically, thus : 
 
 H H 
 
 A large number of careful experiments made in 
 different ways show that this is the case. It must 
 be clearly understood that the particles or atoms 
 are not mixed together like sand and sugar, but 
 are very closely combined more like the links in 
 a chain, and could not be separated by any ordi- 
 nary mechanical means. This state is known as 
 *' chemical combination" as distinguished from 
 the ''mechanical mixture" of the sand and sugar. 
 
26 CHEMICAL ARCHITECTUKE 
 
 Let US take another of tlie commonest things in 
 the world, namely, the air we breathe. This con- 
 tains oxygen among other things and there are 
 several ways in which we can remove it, one of 
 the easiest of which is by means of the pyrogallic 
 acid and soda used for developing photographic 
 plates; another method being by passing the air 
 over red-hot copper filings. Suppose we do pass a 
 measured quantity of air over red-hot copper, or, 
 through this photographic developing solution, we 
 shall find that about one-fifth of it has disappeared 
 — this is the oxygen. The other -four-fifths con- 
 sist of a gas called nitrogen, besides very small 
 quantities of other things which need not concern 
 us for the moment. 
 
 Ammonia. 
 
 Now suppose we take some of the hydrogen 
 from our first experiment, mix it with the nitro- 
 gen just obtained and pass the electric discharge 
 through it. We shall find that after a short time 
 the mixture smells strongly of ammonia and fur- 
 ther examination would show us that the nitrogen 
 and the hydrogen had combined to form ammonia 
 gas, one of nitrogen combining with three of 
 hydrogen ; so that we see that anmionia is : 
 
 — H 
 — H 
 
CHEMICAL ARCHITECTURE 27 
 
 Marsh Gas. 
 
 If we were to collect some of the bubbles of gas 
 which arise from stagnant marshy water contain- 
 ing decaying vegetable matter which we often see 
 in ponds by the roadside, we should find, if we had 
 the proper means of analyzing it, that is to say, 
 splitting it up into its component parts, that it was 
 made up of one part of carbon (charcoal, black 
 lead, anthracite, etc., are more or less pure forms 
 of carbon) and four parts of hydrogen, or to put it 
 graphically 
 
 H- -H 
 H— ^— H 
 
 Similarly there are other compounds which con- 
 tain even more particles of hydrogen, combined 
 with one particle of the substance in question, but 
 these will not concern us much at present. 
 
 Chlorine. 
 We have now before us the following types: — 
 
 Water. Ammonia. Marsh Gas. 
 
 H_-0_H N=H ^tCZg 
 
 There is yet one more type necessary to complete 
 the set, namely, that in which the particle of 
 hydrogen combines with only one particle of 
 
28 CHEMICAL ARCHITECTTJBE 
 
 another substance and we get that in hydro- 
 chloric acid (known in its impure forms as 
 muriatic acid or spirits of salt). If we take a few 
 drops of this acid or rather the solution of it which 
 is sold commercially and add two or three drops 
 of nitric acid to it, a greenish yellow gas will be 
 given off with a very choky irritating smell. This 
 gas is called chlorine and is the basis of all the 
 chlorine bleaching agents. It combines with hy- 
 drogen so violently that if we mix the two gases 
 and expose the mixture to sunlight an explosion 
 will occur, and the resulting substance, known as 
 hydrochloric acid, contains one of hydrogen united 
 to one of clilorine, thus : 
 
 H— CI 
 
 We now have our types complete ; hydrogen com- 
 bining with chlorine one to one ; with oxygen two 
 to one ; with nitrogen three to one ; and with car- 
 bon four to one. 
 
CHAPTER III 
 
 AliKALIES 
 
 Going back to the beginning again, we find by 
 experiment that water was made np of two par- 
 ticles of hydrogen to one of oxygen, thus : 
 
 H— 0— H 
 
 Suppose we take a small piece of the metal called 
 sodium, which at ordinary temperature is quite 
 soft like cheese, although when freshly cut it has a 
 bright metallic surface ; cut pieces about the size of 
 a small pea off it and drop them into a little basin 
 of water, and we shall see that they cause great 
 commotion in the liquid, flying about over the 
 surface as if they were alive; while a stream of 
 whitish matter is left as a trail, like the sparks 
 from the tail of a rocket. When the pieces of 
 sodium have come to the end of their course and 
 disappeared in the water, we shall find that it has 
 a soapy taste and will turn red litmus paper blue. 
 Moreover, if we had applied a light to the particles 
 of sodium we should have found that an inflam- 
 mable gas was being given off, which would light 
 and continue to burn so long as the action lasted. 
 
 29 
 
30 ALKALIES 
 
 This gas was hydrogen and what was happening 
 was that the sodium was turning out part of the 
 hydrogen from the water and taking its place, 
 
 thus : — 
 
 H— 0— H Water. 
 Sodium — — H Caustic Soda. 
 
 forming caustic soda. If we continued to add 
 sodium until all the water were decomposed we 
 should get a solid mass of pure white caustic soda. 
 
 Sodium Oxide. 
 
 If we went on adding sodium after all the water 
 had been converted into caustic soda and applied 
 heat, a further action would take place, in which 
 the remainder of the hydrogen would be turned 
 out, forming : — 
 
 Sodium — — Sodium 
 
 or sodium oxide with no hydrogen in it at all. 
 
 Alkalies, Acids and Salts. 
 
 The caustic soda, which we succeeded in making 
 just now is a typical alkali. And we discovered, 
 it had a soapy taste and would turn litmus paper 
 blue. It has another property also: if we add 
 dilute acid to it, say, the hydrochloric acid we 
 were speaking of above, we shall find that if we 
 add it little by little we shall arrive at a point 
 when litmus paper ceases to be turned blue; 
 
ALKALIES 
 
 31 
 
 neither is it turned red. This is the neutral point 
 when the acid and the alkali have extinguished one 
 another, so to speak, by combining to form some- 
 thing else; in this case sodium chloride or com- 
 mon salt. In putting it graphically we find it 
 convenient to write sodium and we cannot use the 
 letter ^'S," for that is used to designate sulphur, 
 so that in chemistry we employ the first two letters 
 of its Latin name (natrium) ; consequently the 
 action between the caustic soda and the hydro- 
 chloric acid may be put graphically thus : — 
 
 After 
 
 Common 
 Salt 
 
 Water 
 
 Na 
 
 OH 
 
 CI 
 
 H 
 
 Caustic Soda 
 
 Hydrochloric Acid 
 
 W 
 
 From the diagram we see that when the acid and 
 the alkali act upon one another, salt and water are 
 formed. In this particular case the salt formed 
 is common salt — sodium chloride; but in every 
 case where an alkali and an acid come together a 
 salt of some kind and water is the result. For 
 example, when oleic acid — the waste fatty matter 
 from the candle factory — is mixed with caustic 
 
32 ALKALIES 
 
 soda, sodium oleate and water are formed. So- 
 dium oleate is olive oil soap; so that soap, al- 
 though in some ways a complicated substance, is 
 similar in its construction to common salt or so- 
 dium chloride ; but of that more later. 
 
 Sodium Carbonate. 
 
 For our next experiment, suppose we arrange 
 a series of vessels connected together by tubing 
 (quite an easy matter to do in a laboratory where 
 we have the necessary appliances) so that we can 
 burn a piece of charcoal in the first vessel and 
 pass the products of combustion through some 
 caustic soda solution in another vessel. If before 
 the experiment we weighed the piece of charcoal 
 and the vessel containing the caustic soda (to 
 which, by the way, would have to be attached 
 another vessel containing a substance which would 
 retain any water lost by the caustic soda solution 
 and carried forward by the current of air) we 
 should find that the caustic soda had increased in 
 weight by considerably more than the weight of 
 the charcoal. As a matter of fact, determined by 
 a large number of experiments, it has been found 
 that in burning the charcoal, one particle of carbon, 
 to use the chemical term, combines with two par- 
 ticles of oxygen to form a gas known as carbonic 
 acid gas, and this gas is absorbed by the caustic 
 soda to form sodium carbonate, which accounts 
 
ALKALIES 33 
 
 for the increase of weight we observed. To go 
 back to graphic diagrams we have marsh gas : — 
 
 — H 
 
 C_H 
 — H 
 
 Now we remember that oxygen combines with 
 two of hydrogen to form water, that is to say, one 
 of oxygen is equivalent to two of hydrogen. Con- 
 sequently, if carbon combines with oxygen instead 
 of hydrogen it will only require half the number 
 of particles of the latter, and we should expect to 
 find that carbonic acid gas is constructed accord- 
 ing to the diagram : — 
 
 which experiment shows to be the case. For the 
 sake of convenience this is written CO2 ; the marsh 
 gas referred to above being CH4 ; water H2O, and 
 so on. 
 
 Sodium Carbonate and Bicarbonate. 
 
 There are two combinations of caustic soda with 
 carbonic acid — the ordinary carbonate which we 
 made just now, and the bicarbonate, these being 
 formed according to the amount of carbonic acid 
 present. The latter does not become a true acid 
 
34 ALKALIES 
 
 until it is dissolved in water, so that carbonic acid 
 proper is HoO, CO2, the two carbonates of sodium 
 just referred to being : — 
 
 XT 
 
 TT 0. CO2 Carbonic Acid 
 
 Na— 
 
 XT 0. CO2 Sodium Bicarbonate 
 
 Na— 
 
 TVT 0. CO2 Sodium Carbonate 
 
 Na — 
 
 Soda Crystals. 
 
 The last, or Na^ CO3, to put it in more con- 
 venient form, is the ordinary carbonate, with 
 which launderers are so well acquainted under 
 the forms of washing soda, soda crystals, 58 per 
 cent, alkali, and soda ash, the differences between 
 them being due to the amount of water they con- 
 tain. If we take a solution of sodium carbonate, 
 made by dissolving up any of the forms referred 
 to above, and evaporate the water away by 
 heating the solution in a glass or porcelain vessel, 
 we shall see that when a certain amount of water 
 has been driven oif, the solution will begin to 
 crystallize if allowed to stand. These crystals, 
 however, are not pure sodium carbonate ; in crys- 
 tallizing a certain definite proportion of water be- 
 comes entangled in the crystals, and many crys- 
 tals, which to all appearances are quite dry and 
 
ALKALIES 35 
 
 hard, contain quite a large proportion of water 
 combined with the substance in question. In the 
 case of soda crystals or washing soda which is 
 what we have just secured by allowing our con- 
 centrated solution to crystallize, the crystals con- 
 tain no less than ten particles of water to each 
 particle of sodium carbonate ; so that when we buy 
 our sodium carbonate in this form we are buying 
 a large amount of water as well. The dry pow- 
 dered alkali so much in use is practically pure dry 
 sodium carbonate and is the most convenient and 
 economical form to employ. 
 
 Potash. 
 
 Wood ash, known commercially as '' potashes" 
 and in a more refined state as "pearlash," is very 
 similar in composition to washing soda, the differ- 
 ence being that a metal called potassium replaces 
 sodium. This metal resembles sodium very closely. 
 When thrown upon water it turns out the hydro- 
 gen even more violently than the sodium does and 
 the heat produced is so great that the gas usually 
 takes fire of its own accord, burning with a bright 
 violet flame in strong contrast to the yellow flame 
 of the sodium. Not only caustic potash and caustic 
 soda and the carbonates above referred to, but all 
 the compounds of these two metals resemble one 
 another very closely. At one time potash, obtained 
 from wood ash and the ashes of seaweed was the 
 
36 ALKALIES 
 
 common form of alkali in use, and it is only com- 
 paratively recent that the progress of chemical 
 science has brought into use methods for obtain- 
 ing the compounds of sodium from common salt. 
 Consequently the alkaline materials obtained from 
 sodium are now very much cheaper than the corre- 
 sponding jDotassium compounds. As the letter 
 ''P" is used to denote phosphorus in chemical 
 notation the first letter "K" of the Latin name 
 of potassium (Kalium) is used as its symbol, so 
 that the carbonates of potassium are written in 
 chemical shorthand as : — 
 
 KHCO3 Potassium Bicarbonate. 
 K2CO3 Potassium Carbonate (potashes, 
 pearlash, barilla, etc.). 
 
 Unlike sodium carbonate, however, which, as just 
 explained, crystallizes with ten parts of water, 
 carbonate of potassium crystallizes with only two 
 parts. Nevertheless, while ordinary washing soda 
 will keep dry in an open vessel for any length of 
 time, carbonate of potash attracts moisture from 
 the air if not kept covered, and becomes sloppy. 
 
 Caustic Ammonia. 
 
 Curiously enough ammonia although it is a com- 
 pound of nitrogen and hydrogen (see page 26) 
 behaves just as if it were a metal like sodium or 
 potassium and forms a compound with water — 
 
ALKALIES 37 
 
 ordinary liquor ammonise — and a series of salts. 
 These do not greatly concern the lannderer ; except 
 as a matter of general interest. Liquor ammoniae, 
 that is to say the solution of ammonia gas in 
 water, which is in general use, corresponds chem- 
 ically to caustic soda and caustic potash. 
 
 Just as potassium and sodium hydrates (caustic 
 potash and caustic soda) have the composition 
 
 KOH and 
 NaOH 
 
 so ammonia gas when passed into water combines 
 with it to form ammonium hydrate or caustic 
 ammonia. 
 
 NH4OH 
 
 Although it behaves so much like caustic soda 
 and caustic potash, ammonia does not possess the 
 same destructive action on fibres. Consequently it 
 possesses many advantages for laundry use, as it 
 can be used for washing flannels and delicate 
 fabrics, where caustic potash or soda or even 
 washing soda would be out of the question. It 
 must be remembered, however, that ammonia 
 turns white silk yellow and has the same tendency 
 on white flannels ; so that in spite of its advantage 
 over the ''fixed" alkalies, ammonia must be used 
 with caution. Besides ordinary caustic ammonia, 
 that is to say, the liquor ammonise just referred to, 
 
38 ALKALIES 
 
 ammonia forms carbonates, just like sodium and 
 potassium. They are not used, at all events to any 
 extent, in the laundry, as the liquid ammonia is 
 more convenient. 
 
 Borax. 
 
 This is a suitable place to refer to another alka- 
 line substance which is largely used in laundries, 
 namely, borax. This is a compound of soda with 
 boracic acid. Like carbonic acid, boracic acid is 
 a very weak acid and soda is a very strong alkali^ 
 Consequently the com^Dound of the acid and alkali 
 results not in a neutral salt, as would be the case 
 of the compound of soda with hydrochloric acid, 
 but in an alkaline salt, v Borax acts very much like 
 weak carbonate of soda and while it will soften 
 water, neutralize acids, and act as a mild detergent 
 has very little injurious action on fabrics. 
 
 Too Much Alkali. 
 
 Before leaving the subject of alkalies for the 
 present, it would be well to say a word or two 
 about one of the commonest^^perhaps the com- 
 monest — fault of the launderer, namely, the use 
 of an excess of alkali in the washing process. This 
 is not only wasteful, but is one of the most usual 
 causes of bad color and deterioration of linen. 
 Careful experiments have shown that the habitual 
 use of a hot solution of alkali, even when weak, 
 
ALKALIES 39 
 
 has a destructive effect on the fibres of linen and 
 cotton, especially the former. In most cases the 
 use of an excess of alkali in the washer is due to 
 either habit or ignorance, but some launderers 
 of a scientific turn of mind may argue that because 
 the mercerizing process, in which the cotton fibre 
 is exposed to the action of strong alkali, actually 
 strengthens the fibre, therefore the use of alkali 
 in the wash water can have no injurious effect. 
 It must be remembered, however, that the condi- 
 tions are totally different ; in the case of the mer- 
 cerization, the alkali, although strong, is used cold, 
 and is thoroughly rinsed out of the fibre when the 
 action is complete; while in the washing process, 
 the alkali, although comparatively weak, is used 
 hot and the last traces are not always removed in 
 the rinsing. Furthermore, there is a danger of 
 the concentration of the alkali under the heat of 
 the iron, if not completely rinsed out, and its 
 action on the fibre at the high temperature of the 
 iron would be considerable. Eecent experiments 
 show that even such a weak wash water as that 
 containing 0.1 per cent, of sodium carbonate, that 
 is to say, 1 lb. in 100 gallons of water, has an 
 appreciable effect on the fibre if used repeatedly, 
 as it would be in the ordinary round of the weekly 
 wash, especially in yellowing it. I cannot point 
 out too strongly the inadvisability of employing 
 the excess of alkali, which is so dear to the heart 
 
40 ALKALIES 
 
 of the average washman; it is remarkable how 
 difficult it is to correct a bad practice which has 
 gone on so long that it has become habitual. Car- 
 bonate of soda is bad, but caustic soda, which is 
 so largely used in America, is very much worse. 
 I shall, however, deal with this matter more fully 
 in the chapter on the "Chemistry of the Wash- 
 room." 
 
 The Action of Alkalies on Wool. 
 
 Injurious as alkali is to linen and cotton, it is 
 infinitely more so to wool and silk. So great is 
 the injury done to these fabrics by alkali that the 
 use of the fixed alkalies in washing woolens and 
 silks should be rigorously excluded, ammonia 
 being substituted. Potash salts are found occur- 
 ring naturally to a considerable extent in wool, 
 and carbonate of potash (pearlash) is therefore 
 less injurious than carbonate of soda, but in spite 
 of that it is not safe to use it ; ammonia is much 
 more suitable. It is very advisable also to employ 
 ammonia instead of soda when washing delicate 
 linen or cotton goods, and especially in the case of 
 colored fabrics. If the color happens to be affected 
 by alkali, as is not infrequently the case, it is much 
 more readily restored when ammonia is used than 
 when a fixed alkali is employed. A fixed caustic 
 alkali, such as caustic soda or caustic potash, is 
 most destructive to woolen or silk fabrics, and 
 
ALKALIES 41 
 
 even the carbonated alkalies, if used in even weak 
 solutions, have a tendency to render woolen fabrics 
 harsh to the feel. While the greasiest woolens can 
 be cleaned by a neutral soap solution (given suffi- 
 cient time for it to act), yet where it is necessary 
 to employ an alkali, weak ammonia should be used. 
 Even ammonia has a deteriorating action on silk, 
 and where an alkali is necessary, weak borax, say 
 i/^-lb to 10 gallons of wash water is the safest to 
 employ. 
 
CHAPTER IV 
 
 Acids 
 
 So much for alkalies. Acids do not concern the 
 launderer very much directly, but they do occa- 
 sionally, and in any case it is necessary to under- 
 stand something about acids, as it is essential to 
 the proper comprehension of many other things. 
 I explained above that in the case of one acid 
 — ^hydrochloric — its composition was made up of 
 one particle of hydrogen and one particle of an- 
 other gas called chlorine, that is to say, hydro- 
 chloric acid is chloride of hydrogen, just as com- 
 mon salt is chloride of sodium. It is the distin- 
 guishing feature of all acids without exception 
 that they are salts of hydrogen. Thus sulphuric 
 acid is hydrogen sulphate ; phosphoric acid, hydro- 
 gen phosphate; acetic acid, hydrogen acetate; 
 oxalic acid, hydrogen oxalate ; and so on. This is 
 equally true of the fatty acids which combine with 
 alkalies to make soap, as we shall see later on; 
 oleic acid, for example, is hydrogen oleate. Where 
 an acid is of simple composition, like hydrochloric 
 acid, only one kind of salt is possible, but where 
 the composition is less simple, as in the case of 
 
 42 
 
ACIDS 43 
 
 sulphuric acid (oil of vitriol), two kinds of salts 
 are possible. In chemical shorthand, sulphuric 
 acid, or hydrogen sulphate, is written 
 
 XT SO4 
 
 or, for convenience, H2SO4 and it will be seen 
 from this, to compare it with hydrochloric acid, 
 
 H— CI 
 
 that there are two hydrogens which can come into 
 operation to form salts. Thus : 
 
 HCl Hydrochloric acid. 
 
 NaCl Sodium Chloride. 
 
 H2SO4 Sulphuric acid. 
 
 NaHSOi Acid Sodium Sulphate. 
 
 Na.SOi Normal Sodium Sulphate. 
 
 Similarly : 
 
 H2CO3 Carbonic acid (solution in 
 
 water H^O— COo) 
 NaHCOs Sodium Bicarbonate. 
 
 NagCOs Sodium Carbonate (normal 
 
 carbonate, washing soda, 
 soda crystals, etc.). 
 Strong and Weak Acids. 
 
 What, to use a convenient term, is known as a 
 strong acid, can turn out a weak acid and take its 
 place as a rule in a chemical combination. For 
 instance, carbonic acid is comparatively a weak 
 
44 ACIDS 
 
 acid, and if a carbonate such as washing soda (car- 
 bonate of soda) or chalk (carbonate of lime) be 
 brought into contact with a strong acid, such as 
 sulphuric acid, the carbonic acid is turned out and 
 escapes as gas with much effervescence, while the 
 sulphuric acid takes its place to form suljDhate of 
 soda or sulphate of lime as the case may be. This 
 is useful to the launderer in many ways. If he is 
 using unsoftened water containing lime salts, this 
 is very likely to be deposited in the linen, causing 
 not only bad color, but actually destroying the 
 fibre. Acid will remove this and, after rinsing, 
 the fibre will be entirely free from deposits of 
 lime. 
 Lime and Lime Soap. 
 
 This is such an important point that it would be 
 well to say a little more about it. The most famil- 
 iar form of carbonate of calcium, or carbonate of 
 lime, as it is perhaps more usually called, is chalk, 
 which, although apparently formless, is not really 
 so ; under the microscope it will be seen to be com- 
 posed of minute shells of tiny beings which are 
 still found living in enormous quantities in the 
 waters of the Atlantic and other oceans. When 
 they die their shells fall to the bottom and form an 
 ooze, which afterward becomes consolidated by 
 pressure and forms chalk. There are, however, 
 many well-known crystalline forms of carbonate 
 of lime, such as marble and calc spar. When a 
 
ACIDS 45 
 
 hard water is softened in a washing machine by 
 means of soda or some other alkali, as it usually 
 is in laundries which do not possess a water soft- 
 ener, the lime salts are thrown out of solution as 
 carbonate of lime. "While a good deal of this is 
 in a loose, formless, powdery condition suspended 
 in the water, an appreciable amount of it is depos- 
 ited as tiny sharp crystals in the fibres of the 
 linen, and when dry has a most destructive action 
 in cutting to pieces and wearing away the fibres. 
 Much of the apparently unaccountable rapid wear 
 on linen goods is due to this cause, which very 
 few launderers take into account. By giving the 
 linen a soaking in weak acid after the first rinse, 
 these lime crystals are dissolved and rendered 
 harmless, being entirely removed in the last rinse. 
 If this is not done, a fresh deposit of crystals takes 
 place in each wash of the garment, so that 
 although in a single wash the quantity of carbon- 
 ate of lime deposited is hardly appreciable, it 
 increases rapidly until finally it becomes a most 
 serious agent in the destruction of the goods. 
 
 There is another matter also in connection with 
 this lime question, deserving of the most serious 
 consideration ; I refer to deposit of lime soap. As 
 I explained some little time ago soap is a salt just 
 in exactly the same way that common salt (sodium 
 chloride) is a salt; instead of a combination be- 
 tween hydrochloric acid and soda, soap is formed 
 
46 ACIDS 
 
 by a combination between soda and a vegetable 
 fatty acid, such as oleic acid — the principal fatty 
 acid found in olive oil; so that olive oil soap is 
 sodium oleate, just as washing soda is sodium 
 carbonate. 
 
 We have seen that when washing soda and a 
 lime salt come together, carbonate of lime is 
 formed; an exactly similar thing happens when a 
 lime salt and soap, the olive oil soap just referred 
 to for instance, come into contact ; instead of the 
 carbonate of lime, oleate of lime — lime soap — is 
 formed. This is an insoluble pasty material 
 which causes a launderer no end of trouble. It 
 forms the well-known deposit in his washing ma- 
 chine; it forms objectionable streaks and marks 
 on his clean linen, and also the black specks which 
 are not infrequent in the shirt fronts in some laun- 
 dries using hard water ; and last, but not least, an 
 habitual deposit of this lime soap, together with 
 lime salts referred to above, cause the linen to 
 possess a dull leaden color, instead of the pearly 
 whiteness it ought to have. 
 
 The easiest way to remove all this trouble is to 
 put in a water softener, but without that, the acid 
 bath after the first rinse will come to the laun- 
 derer 's rescue. Its action upon the deposit of 
 carbonate of lime has already been explained ; its 
 action upon lime soap is very similar; the acid, 
 being stronger, so to speak than the olive or other 
 
ACIDS 47 
 
 fatty acid of the soap, throws it out of combina- 
 tion, taking its place to form a salt with the lime. 
 It is necessary to use the acid bath or acid rinse, 
 hot, like the first rinse, otherwise the free fatty 
 acid might form streaks of fatty matter on the 
 linen, but if the water be hot, the globules of fatty 
 matter are kept melted and carried off with the 
 water. 
 
 The Use of Acetic Acid. 
 
 The next question arises as to which is the best 
 acid to use for the acid rinse. Hydrochloric acid 
 is not suitable, as in the hot water it would be 
 somewhat volatile, and moreover the cheaper com- 
 mercial forms of the acid contain iron, which 
 would possibly help to discolor the linen. Sul- 
 phuric acid is very suitable if used in proper pro- 
 portion, but it is essential that it should be thor- 
 oughly rinsed out; otherwise, if only quite a 
 minute quantity of the acid be left in the fabric, it 
 will concentrate when dry and char the fibres. 
 Oxalic acid has many advantages and is largely 
 used to follow the bleach, which seems to be an 
 integral part of the average washing process in 
 America, but this also, if not thoroughly removed, 
 has an injurious action on fabrics. The best is 
 acetic acid (known in the dilute state as vinegar). 
 It is volatile, and any trace which may have been 
 left in the goods will be completely driven off in 
 
48 ACIDS 
 
 the drying room ; moreover, it possesses no injuri- 
 ous action on the fibres. For ordinary work a 
 quarter of a pint of the commercial acid should 
 be used to each 10 gallons of water in the washing 
 machine. After the acid rinse can come the ordi- 
 nary cold rinse with blue. 
 
 Acetic Acid. 
 
 Commercial acetic acid is obtained from the 
 distillation of wood, being known as pyroligneous 
 acid. After purification it becomes acetic acid 
 and is used for various commercial purposes, one 
 of the most important being the adulteration of 
 vinegar. In commerce it is usually sold in casks, 
 and has a strength of about 40 per cent. This is 
 the material the launderer should use. Glacial 
 acetic acid is practically pure acid and possesses 
 the property of crystallizing below a certain tem- 
 perature. It is much more expensive than the 
 ordinary commercial form and there is no advan- 
 tage in employing it. 
 
 Souring. 
 
 In addition to its use, which I have just de- 
 scribed, for removing lime after washing, acetic 
 acid is usually employed for ''souring" after 
 bleaching, in England, but oxalic acid is most 
 favored in America — probably on account of con- 
 venience of carriage. I will describe the action 
 that takes place, when I come to bleaching. 
 
CHAPTER V 
 
 Soaps 
 
 It has already been explained that a soap is as 
 much a salt as common salt. The latter is formed 
 by a combination of soda with hydrochloric acid, 
 while a soap is a compound of soda or some other 
 alkali with what is known as a fatty acid. Just 
 as soda is not the only alkali which can form a 
 chloride, so it is not the only alkali which can 
 form a soap. Nearly every metal, such as calcium 
 (lime), lead or copper, forms a chloride, and simi- 
 larly these metals are quite as capable of forming 
 soaps ; although nearly all these soaps are insolu- 
 ble in water. The animal and vegetable fats, of 
 which there are a very large variety, resemble one 
 another very closely ; all are compounds of glycer- 
 ine with one or other of the fatty acids. These, 
 while they vary a good deal in composition, are 
 very similar in their broad characteristics; the 
 free acids, from which the glycerine has been sepa- 
 rated, being greasy, water repelling, and having 
 in appearance, feel, taste and smell, nearly all the 
 characters of the complete fats. Practically all 
 fats can be used for soap making, and are, except 
 
 49 
 
50 SOAPS 
 
 where their cost is prohibitive. In addition to the 
 ordinary well-known fats and oils, such as tallow, 
 olive oil, linseed oil, rape oil, cotton seed, palm and 
 other vegetable oils, a large number of oils now 
 obtained from tropical trees find their way to 
 the soapmaker. Moreover, fish oils are used for 
 making the cheaper kinds of soft soap, their evil 
 odor being disguised by the more powerful one of 
 nitrobenzol, which gives the smell and flavor of 
 almonds. 
 
 Leaving fish oils out of the question as being 
 quite unsuitable for laundry purposes on account 
 of the evil smell they would inevitably leave be- 
 hind, the value of a fat or oil for industrial pur- 
 poses depends largely on its melting point, that is 
 to say, on the amount of the fat known as stearin 
 the oil contains. This fat on account of its hard- 
 ness and high melting point is greatly valued for 
 candle making, all the best candles, apart from 
 wax candles, being made largely or wholly of this 
 substance. As it has an important bearing on 
 the subject I must devote a few more words to 
 candlemaking before I deal with soapmaking 
 itself. The first thing a candle maker does after 
 cleaning the fat, is to separate the glycerine by 
 treatment with steam at a high pressure, and thus 
 secure the free fatty acid, or rather acids, for all 
 natural oils and fats consist of a mixture of sev- 
 eral fatty acids, the most common being oleic 
 
SOAPS 51 
 
 acid (the predominant acid in olive oil), palmitic 
 acid (the principal acid in palm oil), and stearic 
 acid (the chief constituent of tallow and the heavy 
 animal fats). By processes which I need not 
 describe here, the heavy fatty acids are then 
 separated from the lighter ones, the former being 
 nsed for candles, while the latter are employed 
 for soapmaking and for manufacturing purposes, 
 such as lubricating worsted during spinning. This 
 light fat or oil consists very largely of oleic acid, 
 and is known commercially as ''red oil" on ac- 
 count of its color. I shall have occasion to refer 
 to it again later. 
 
 Oils Used in Soapmaking. 
 
 As might be expected the character of the soap 
 — I am referring now to "hard" soaps — depends 
 very much upon that of the oils or fats employed 
 in its manufacture. A soap made from tallow 
 which consists largely of stearin will be hard and 
 solid, and will possess a high lathering power; 
 while one made from olive oil will be compara- 
 tively soft and will give a lighter lather. Although 
 the lathering capabilities of a soap form one of 
 the principal guides of the washman, yet this is a 
 somewhat deceptive characteristic. Although an 
 oil soap gives a comparatively poor lather it may 
 be doing its work in the machine just as well as 
 the mottled soap with a fine head of froth upon it. 
 
52 SOAPS 
 
 Moreover, some vegetable oils which are not neces- 
 sarily any better in their cleansing capabilities, 
 give a very much stronger lather than others. 
 Cotton seed oil, for example, when made into soap 
 gives a good lather, while sesame oil, used very 
 largely in making what are known as ' ' olive ' ' oil 
 soaps gives a comparatively poor lather. 
 
 Mineral Oils. 
 
 To prevent confusion I may here say that the 
 mineral oils, such as paraffin and petroleum, are 
 not oils at all in the sense in which we have been 
 using the word. Their composition is entirely 
 different; they contain no glycerine and no fatty 
 acid; they are what chemists call hydro-carbons, 
 like coal gas or naphtha, and it is quite impossible 
 to make soap from them. It is true they are some- 
 times incorporated with soap in small quantities 
 with a view to increasing its detergent properties, 
 but this matter will be dealt with later. 
 
 Hard and Soft Soaps. 
 
 Not so very many years ago when chemical 
 manufacture was in its infancy, the alkali for 
 soapmaking was not soda, but potash, and was 
 obtained from the ash of seaweed and other plants, 
 but with the invention of processes for making 
 soda from common salt, soda rapidly replaced 
 potash for this purpose. Soaps made from soda 
 
SOAPS 53 
 
 are comparatively solid, and are known as ''hard" 
 soaps; while potash soaps are quite soft at ordi- 
 nary temperatures and are known as "soft" 
 soaps. A temporary soap can be made with 
 ammonia, but this can only be used in solution. 
 Nevertheless, it forms a very useful soap and I 
 shall describe it later. "Yellow" soap is some- 
 what different from ordinary hard soap and con- 
 tains rosin, which replaces a certain proportion of 
 fat. 
 
 Soaps are made by two main processes, the 
 "boiled" and the "cold" process. In the latter 
 the caustic soda and the oils are mixed cold, or 
 but little heated, and the heat produced by the 
 chemical action is sufficient to carry out the 
 process. This method is, however, only used on a 
 very small scale by perfumers and small toilet 
 soap vendors and has the disadvantage that the 
 resulting soap always contains an appreciable 
 amount of free alkali. 
 
 Boiled soaps constitute well over 90 per cent of 
 those on the market and are the only ones that 
 need occupy the attention of the launderer. Soap- 
 making now is conducted on an enormous scale, 
 huge pans capable of making 20 to 30 tons of soap 
 at a time being employed. Each pan is heated by 
 two steam coils, one closed for heating purposes 
 only and the other perforated, so that live steam 
 can be blown direct into the liquid. This serves 
 
§4 SOAPS 
 
 not only to supply heat, but to keep the mixture 
 agitated while the operation is in progress. 
 
 Boiled soaps are essentially of two kinds — 
 ''curd" soaps and "fitted" soaps. The best exam- 
 ple of the latter is yellow soap. The first opera- 
 tion in making curd soap is to run in the requisite 
 amount of melted fat, which may consist entirely 
 of tallow, or of tallow mixed with other fats. A 
 weak solution of caustic soda is then run in and 
 steam turned on. It is necessary to begin with a 
 weak solution, as saponification will not commence 
 with strong alkali. As soon as saponification is 
 proceeding satisfactorily, more and stronger alkali 
 or "lye" as the soapmaker calls it, is run in, and 
 the operation is allowed to continue until nearly 
 the whole of the fats are converted into soap. 
 
 While soap is soluble in water it is not soluble 
 in brine, and the next step is to throw into the pan, 
 quantities of salt, which causes the soap to crys- 
 tallize out at the top, the solution of the brine con- 
 taining all the glycerine and impurities being at 
 the bottom. This is now run oif and is a valuable 
 asset to the soapmaker, as the lye is run over to 
 the glycerine plant, where it is recovered and puri- 
 fied. The demand for glycerine — chiefly for mak- 
 ing dynamite — is very great, and the sale of the 
 glycerine, which used at one time to be thrown 
 away with the waste lyes, is now the most profit- 
 able part of soapmaking. 
 
SOAPS 55 
 
 When the lye has been run off, fresh strong 
 alkali is added, and the soap is boiled np again to 
 insure complete saponification. After this the 
 soap is allowed to settle and is run off into large 
 moulds or * 'frames" as the soapmaker calls them, 
 where it cools and solidifies. The sides of the 
 frame are then taken away, the solid block of soap 
 being left, which is cut up into bars. 
 
 Curd Mottled Soap. 
 
 The fats used for making a good curd soap 
 should contain not less than 60 per cent of tallow. 
 On account of the process of manufacture, it 
 always contains a certain amount of free alkali, 
 but for ordinary laundry purposes this is no draw- 
 back. Nevertheless, it forms an important reason 
 why curd soap should not be used for washing 
 flannels, woolens, colored goods or delicate fabrics. 
 Mottled soap is, or should be, a curd soap. In 
 the old days when chemical manufacture was in a 
 crude state, the alkali employed contained several 
 impurities including iron, which, when the soap 
 was run out into the frames, settled out to form 
 the well-known streaks or mottling. Nowadays 
 the alkali contains no impurities of this kind to 
 form the coloring matter, so that it has to be added 
 artificially. Curd, mottled soap, is perhaps the 
 safest soap for the average launderer to purchase 
 for general use, as no means have yet been found 
 
56 SOAPS 
 
 for adulterating it. The proper mottling cannot 
 be obtained unless a pure soap is employed, and 
 the launderer should notice the character of the 
 mottling and see that the "strike" is sharp and 
 not dirty. 
 
 Soap Chips. 
 
 A form of soap which is very popular in Amer- 
 ica is known as soap chips, which contains very 
 little water, and 70 per cent or more of fatty acid. 
 Its great advantage is that there is practically no 
 carriage to pay on water — a very important mat- 
 ter considering the enormous distances it some- 
 times had to travel. One of the drawbacks of this 
 soap, however, is that a considerable separation 
 of free fatty acid takes place on dissolving it, 
 necessitating the addition of alkali to resaponify 
 the fat and keep it dissolved. I shall deal further 
 with this soap in the chapter on the washroom. 
 
 Yellow Soap. 
 
 Nearly all of the other soaps are fitted soaps, in- 
 cluding yellow soap above mentioned. One of the 
 principal constituents of this soap is rosin, which 
 combines with alkali and acts very much after the 
 manner of soap. For this reason, if present in 
 proper proportion, the rosin should not be re- 
 garded as an adulterant. Nevertheless, the quan- 
 tity employed should not exceed 20 per cent of the 
 
SOAPS 57 
 
 amount of fat. The process of making a fitted 
 soap is very similar to that just described up to 
 the point when the lye containing the glycerine is 
 run off. The soap made thus is cleansed by adding 
 water and boiling with steam. Strong brine is 
 then run in and another boil given. When the 
 correct point is reached, which requires a good deal 
 of experience to determine, the brine is run off, 
 a little water added, the whole is boiled with closed 
 steam and the soap is run into frames to cool. 
 
 Adulterations. 
 
 This is the stage when the art of the sophisti- 
 cator is brought into play. As soon as the soap 
 is run into the frames, and before it has begun to 
 cool — a process which takes place rather slowly — 
 adulterants, such as silicate of soda, Glauber's 
 salt, carbonate of soda, and — most important of 
 all — water, can be added and "crutched" into 
 the soap. The object of adding the other adul- 
 terants is to disguise the addition of water and 
 make the soap appear strong and solid, when as 
 a matter of fact it contains a large proportion of 
 water. It is indeed remarkable how much water 
 soap can be made to hold, if added under proper 
 conditions, and still appear solid. Some of the 
 soaps on the market are little better than water 
 standing upright. A great fillip [smart blow] to 
 the manufacture and sale of this class of soap was 
 
68 SOAPS 
 
 given a few years ago, by the increased importa- 
 tion of cocoanut oil, which has a remarkable capa- 
 city for holding water and yet appearing solid. 
 
 Most of the quick washer soaps — "quick 
 waster" soaps would perhaps be a better name — 
 are made from a mixture of cocoanut and cotton 
 seed oils. The mixture of these oils makes a very 
 good soap, but the temptation to lower the price 
 by the addition of water and so attract the unsus- 
 pecting public is very great. This cocoanut-cot- 
 ton-seed oil and water soap dissolves readily and 
 lathers very freely, but is exceedingly wasteful. 
 Our German friends describe it by the very appro- 
 priate name of "schwindel" soap. One drawback 
 to the use of cocoanut oil for soapmaking is that 
 clothes washed with it always possess a somewhat 
 unpleasant smell, and the well-known odor of 
 washing-day is mostly due to the use of cocoanut 
 oil soap. I will describe later how the launderer 
 can estimate approximately the value of the soap 
 he is buying and guard himself from the frauds 
 most usually practiced. 
 
 Oil Soaps. 
 
 Olive oil makes excellent soap and it was prob- 
 ably the first oil used in soapmaking. Mar- 
 seilles and Castile soaps were made originally 
 from olive oil, but nowadays sesame oil, made 
 from the grain of that name, is largely employed 
 
SOAPS 59 
 
 for making so-called olive oil soaps. These soaps 
 are very good and are largely used in the laundry, 
 where they possess many advantages. One draw- 
 back is that they do not lather very freely and do 
 not possess such strong detergent powers as tallow 
 soaps, but as these soaps contain very little ste- 
 arin it is very much easier to rinse the soap out of 
 the goods than is the case with tallow soaps. More- 
 over, partly for the same reason oil soaps are 
 very suitable for washing flannels, colored goods 
 and finery. They should contain no free alkali, 
 and that is another important reason why they 
 should be employed for the purposes just mem- 
 tioned. 
 
 Soft Soaps. 
 
 Soft soaps are made in a very similar manner 
 to hard soaps, potash being employed instead of 
 soda. The best soft soaps are made from olive 
 oil, but linseed oil makes very good soap. Many 
 other vegetable oils, also such as rape oil, are used 
 for making soft soap. While rosin may be con- 
 sidered a normal constituent of yellow soap, it 
 should be regarded as an adulterant if found in 
 soft soap. 
 
 Special Soaps and Soap Powders. 
 
 Among special soaps I may mention first of all 
 the soaps containing some of the lighter petro- 
 
60 SOAPS 
 
 leum oil, which are now on the market. The oil 
 is incorporated with the soap, usually at all events, 
 by mechanical means after the soap is made. Ex- 
 periments have shown that the addition of a 
 small quantity of petroleum is a distinct help in 
 the washing process, but, in the majority of in- 
 stances, the smell of petroleum is very persistent, 
 and even after it has apparently been completely 
 removed will appear again on the clothes being 
 warmed. 
 
 Another special soap is the soap powder which 
 appears on the market in many forms. In mak- 
 ing this the soap is first of all dried in a special 
 machine in which the soap, which is cut up into 
 strips, travels through the machine on a con- 
 tinuous wire band. This method is employed also 
 for making soap chips. It is then ground to the 
 finest power in a disintegrator. These powders, 
 which usually consist of a mixture of soap and 
 soda ash, with or without adulterants, vary very 
 much in quality. Although there are a few good 
 soap powders in the market, the majority are 
 unqualified swindles. Like the little girl in the 
 nursery rhyme ''When they are good they are 
 very, very good ; but when they are bad they are 
 horrid." Their value may be largely estimated 
 by the amount of soap they contain. 
 
 Another soap used to some extent in laundries 
 consists of soap dissolved in methylated spirit. 
 
SOAPS 61 
 
 This soap is very convenient for finery and special 
 work, as it is, or should be, neutral, carbonate of 
 soda being insoluble in alcohol. The spirit assists 
 the detergent action of the soap, and I have seen 
 some beautiful results from silk washed with a 
 soap of this description, the fabric having a par- 
 ticularly bright, fresh appearance. 
 
 Still another soap is the benzine soap used for 
 dry cleaning. This soap does not contain ben- 
 zine, but is dried by special means, so that it con- 
 tains no water and will dissolve readily in ben- 
 zine, giving a clear solution. 
 
 Ammonia Soap. 
 
 While discussing special soaps I must not for- 
 get to mention a very special soap, which laun- 
 derers can make and use themselves without any 
 difficulty. My readers will remember that I ex- 
 plained in a previous chapter that a soap is a 
 compound of an alkali with a fatty acid ; that the 
 compounds of soda with fatty acids are hard 
 soaps; while those of potash form soft soaps. 
 Now ammonia acts almost exactly like caustic 
 soda and caustic potash, although on account of 
 its volatility it is not a fixed alkali. Ammonia 
 forms compounds with free fatty acids, and al- 
 though these are only of a temporary character, 
 they are to all intents and purposes soaps and act 
 just like soaps. By putting in his washer, oleic 
 
62 SOAPS 
 
 acid and ammonia, the launderer has a soap ready 
 made. Oleic acid requires for saponification 6.0 
 per cent by weight of ammonia, that is to say, 
 10 lbs. of oleic acid require approximately 1^/^ 
 pints of strong ammonia solution (specific gravity 
 0.884). In order to make quite sure that the 
 ammonia is there in sufficient quantity, it would 
 be advisable to add a slight excess. The deter- 
 gent powers of this ammonia soap (10 lbs. oleic 
 acid and li4 pints of ammonia) would be equiva- 
 lent to that of 13 lbs. or 14 lbs. of good oil soap. 
 The oleic acid referred to is, as I have mentioned 
 previously, the waste material from the candle 
 works, and is known commercially as "red oil." 
 
 Monopol and Tetrapol Soaps. 
 
 Before I leave the subject of soaps I must not 
 forget to mention the Monopol and Tetrapol soaps 
 which are coming so much into use among cleaners 
 and dyers. Monopol soap is a superfatted sul- 
 phonal castor oil soap and Tetrapol soap is a 
 liquid soap made by mixing the above with carbon 
 tetrachloride. The chapter on "Dyes and Dye- 
 ing" will explain a little what a sulphonated com- 
 pound is. This particular soap has great advan- 
 tages from the wet cleaner's point of view. It 
 will mix with water in all proportions, does not 
 form insoluble compounds with lime (lime soaps), 
 
SOAPS 63 
 
 has remarkable grease dissolving properties, and 
 does not affect the most delicate colors. 
 
 Valuing Soap. 
 
 Now for some instructions as to the estimation 
 of the value of the soap the launderer is using. 
 Although the comj)lete analysis of a soap is a 
 complicated matter requiring extensive knowledge 
 of chemistry and considerable analytical experi- 
 ence, it is a comparatively easy matter to arrive 
 at a rough estimate of the value of any particular 
 soap in a few moments. As I have explained 
 above, the value of soap can for all practical pur- 
 poses be gauged by the amount of fatty acid 
 which it contains, and it is quite a usual thing to 
 see a soap quoted as containing so much per cent 
 of fatty acid. The easiest way to form a rough 
 estimate of this amount is to have two tall glass 
 jars of exactly the same pattern and to make up 
 a standard solution of any well-known and 
 thoroughly reliable soap, dissolving say, four 
 ounces of this soap in water and making it up 
 to exactly a quart. 
 
 When it is desired to test the value of a new 
 consignment or new sample of soap, half an ounce 
 should be carefully weighed out from the middle 
 of the bar, and dissolved in water and placed in 
 one of the tall jars. At the same time 5 fluid 
 ounces (i/4 pint) of the standard solution should 
 
64 SOAPS 
 
 be placed in the other jar and sufficient dilute 
 sulphuric acid added to each jar to decompose 
 the soap and throw down the fatty acid, which 
 will immediately appear as a thick white, flocculent 
 [wooly] precipitate. When this has been done, 
 plain water must be added to each jar until the 
 liquid in both jars is exactly the same height. 
 After standing for, say ten minutes for the pre- 
 cipitate to settle, a glance will show how the 
 amount of fatty acid in the two soaps compares. 
 If a soap contains its proper proportion of fatty 
 acid it is not likely to have much the matter with 
 it in other respects. Fuller instructions for the 
 analysis of soap will be found in the chapter on 
 *' Practical Chemical Works." 
 
 Warnings. 
 
 In valuing soap and soap powders there are 
 certain things for which the launderer should 
 always keep a watch. If he is buying a mottled 
 soap, for example, he should see that he gets a 
 "curd" mottled soap and not a "fitted" soap, 
 which is only an imitation, being usually made 
 from oil instead of principally from tallow. The 
 difference in the appearance of the mottling be- 
 tween a real and a sham mottled soap should be 
 enough to warn any observant launderer as to 
 what he is dealing with. It is not necessarily 
 that the sham mottled soap is a bad soap ; it may 
 
SOAPS 65 
 
 have its full allowance of fatty acids, and yet, as 
 the value of the oil from which it is made is so 
 much less than that of the tallow from which it 
 ought to have been made, the launderer may have 
 a very bad bargain in buying it. If he purchases 
 an oil soap as an oil soap, well and good, but if 
 he purchases it as a curd soap he is probably not 
 getting his money's worth. 
 
 Secondly, never buy a watered soap. You al- 
 ways get much better value if you buy a pure soap. 
 It is not worth anybody's while to pay carriage, 
 maker's profit and traveller's commission on 
 water. 
 
 Thirdly, take care that the soap you use for 
 your flannels and colored goods is neutral. The 
 test for this will be found on another page. 
 
 Fourthly, I have seen it stated that '^yellow" 
 or rosin soaps gradually cause a brown color in 
 linen. I have considerable doubt about the truth 
 of this in practice, as I have seen linen which has 
 been washed over and over again with yellow 
 soap, still have an excellent color. 
 
 Fifthly, keep a careful watch on the smell of 
 the soap you are using. Any unpleasant odor, 
 however slight, has an inconvenient way of lin- 
 gering in the clean linen and there is nothing more 
 likely to cause adverse comment on the laundry 
 and its methods than sending home clean linen 
 with an unpleasant smell in it. For this reason 
 
66 SOAPS 
 
 it is never safe to use petrol or benzine or any 
 soap containing petroleum in any form in the 
 washroom, except possibly for some particularly 
 dirty articles washed under exceptional circum- 
 stances. Even if the smell does not appear to be 
 present when cold it will often reappear as soon 
 as the article is warmed. 
 
 Lastly, take care not to use a soap or washing 
 compound containing silicate of soda. I am con- 
 tinually receiving, for advice, specimens of table 
 linen which have been absolutely ruined with 
 washing compounds of this description. 
 
CHAPTER VI 
 
 Bleaching 
 
 Bleaching should not be a regular part of the 
 laundry process, as, if the washing is properly 
 carried out, bleaching should not be necessary, 
 except in the case of certain articles which are 
 stained, such as table linen, or articles which have 
 been badly washed at other laundries and are 
 properly treated for the first time. Where, as is 
 unfortunately so often the case, excess of alkali is 
 used in washing and the linen becomes yellow, 
 it is necessary to bleach it frequently; otherwise 
 its bad color becomes very objectionable. Also 
 where shirts, collars and body linen have been 
 badly washed, and the organic stains fixed in the 
 fabrics by heat applied too soon, it is necessary 
 to remove these stains by bleaching. 
 
 The Nature of Bleaching. 
 
 Before describing the different materials and 
 methods used for bleaching, it would be well for 
 the reader to understand the essence of the proc- 
 ess. In the first place a colored substance is 
 produced by a definite chemical combination and 
 
 67 
 
68 BLEACHING 
 
 if that combination can be destroyed, the color 
 will be destroyed too. Many dyes, for example, 
 such as phenolphthalein, are colored only in the 
 presence of alkalies or of acids as the case may be, 
 and in nearly all instances further oxidation will 
 form a compound which is colorless. This is 
 not always so, for some colors, such as those 
 produced by the naphthol dyes, cannot be des- 
 troyed by oxidation. In these cases the opposite 
 course must be pursued, and instead of attempting 
 to destroy the color by adding oxygen to the com- 
 pound, oxygen must be taken away from it; that 
 is to say, to use chemical language, it must be 
 reduced. Bleaching with chlorine or its compounds 
 is an instance of oxidation, and bleaching with 
 burnt sulphur or hydradite or titanous chloride 
 is an instance of reduction. An even simpler and 
 more understandable method of oxidation is 
 bleaching by means of hydrogen peroxide and I 
 propose to take this first. 
 
 Hydrogen Peroxide. 
 
 Water, as explained previously, is a compound 
 of one particle of oxygen with two of hydrogen, 
 thus: H — — H. By certain chemical means, 
 which I need not enter into here, it is possible to 
 work in another atom of oxygen, so that a com- 
 pound such as this is formed: H — — — H 
 which contains two atoms of oxygen instead of 
 
BLEACHING 69 
 
 one. This extra atom is held very loosely, and if 
 any readily oxidizable substance be present that 
 substance takes up the extra atom and becomes 
 oxidized at once, while the chemical compound 
 in question, which is known as hydrogen peroxide, 
 returns to the condition of ordinary water. Thus 
 bleaching with hydrogen peroxide is a case of 
 oxidation in its simplest form. 
 
 Hydrogen peroxide is usually sold in two 
 strengths, known as 12 volume and 20 volume, 
 which signifies that, say, a pint of 12 volume 
 hydrogen peroxide is capable of giving off 12 pints 
 of oxygen when decomposed, or 20 pints in the 
 case of the 20 volume. As may be supposed, on 
 account of its composition, neither form is very 
 permanent, but the 12 volume, which is propor- 
 tionately cheaper in price, is much more per- 
 manent than the 20 volume, and is best for the 
 launderer's purpose. For general use in taking 
 stains out of flannels, blankets, or finery of any 
 kind, a 10 per cent solution of the 12 volume 
 strength may be used just as it is. In order to 
 make the peroxide keep better a small quantity of 
 acid — usually phosphoric acid — is added, as this 
 renders the solution much more permanent. "When 
 using it for laundry purposes it is a good plan to 
 add a pinch of chalk or whitening to neutralize 
 this acid. 
 
70 . BLEACHING 
 
 Sodium Peroxide. 
 
 Just as sodium will replace the H's in water, so 
 it will in hydrogen peroxide, and sodium peroxide 
 (Na202) is formed. It is a well-known commer- 
 cial product, and possesses the advantage over the 
 liquid peroxide in being much more permanent. 
 When dissolved in water and treated with acid it 
 acts in exactly the same manner as hydrogen 
 peroxide. 
 
 Nascent Oxygen. 
 
 One of the reasons to which hydrogen peroxide 
 is believed to owe its strong oxidizing properties 
 is that the oxygen is set free from the peroxide 
 exactly at the spot where it is to be used and is 
 in what chemists call the '^ nascent" condition, 
 that is, the oxygen atoms have not formed any 
 combinations among themselves, so that all their 
 energies are available. It must always be re- 
 membered when bleaching or taking stains out of 
 any fabric, that the oxygen atoms are no 
 respectors of persons, so to speak, and will oxidize 
 anything that is open to attack, whether it be the 
 stain you want removed or the coloring matter 
 with which the garment is dyed. Nevertheless, 
 the majority of dyes are less readily open to 
 attack as a rule than the matter which causes the 
 stain, so that if the launderer proceeds judi- 
 ciously he can generally succeed in removing the 
 
BLEACHING 71 
 
 one without interfering much with the other. The 
 important thing in applying all bleaches and stain 
 removers is to confine their actions as closely as 
 may be to the spot where the stain rests, and to 
 rinse them out directly their work is accomplished, 
 before they have time to turn their attention to 
 the coloring matter in the garment. 
 
 Sodium Perborate. 
 
 Quite recently a new and most valuable oxidiz- 
 ing substance has appeared upon the market. 
 Sodium perborate has been known for some time 
 in the laboratory, but has only just become cheap 
 enough to make it available for general use. It 
 is by far the best and most convenient bleaching 
 agent yet introduced for laundry purpose^;.'' It 
 is a white powder and bears the same relation to 
 ordinary borate, (borax) as sodium peroxide 
 does to sodium oxide, the extra proportion of 
 oxygen being directly available for stain remov- 
 ing. Sodium perborate, if kept dry and in a cool 
 place, is quite permanent and all that has to be 
 done to make it ready for use, is to dissolve it in 
 water. When it has given up its oxygen, it goes 
 back to ordinary borax, which is almost innocuous 
 even to silks and flannels and can be used for re- 
 moving stains from these fabrics as well as from 
 cotton and linen goods. Its value is being so 
 widely recognized that a number of compounds 
 
72 BLEACHING 
 
 containing it are being placed upon the market 
 under fancy names. 
 
 Chlorine Bleaches. 
 
 I now come to describe the chlorine bleaches, 
 and it will be interesting to note that the active 
 agent in the bleaching here again is oxygen, which 
 is set free by the action of the chlorine. But 
 before proceeding further I must give a short 
 description of chlorine itself. If a drop of strong 
 hydrochloric acid be placed in a test tube, two 
 or three drops of strong nitric acid be added, and 
 the mixture be warmed, the tube will be filled 
 with a yellowish-green, intensely irritating, suffo- 
 cating gas. This gas, which is chlorine, is a 
 simple substance, like hydrogen or oxygen. It 
 has a great affinity for hydrogen, and if a mixture 
 of the two be brought into strong light they will 
 unite with explosive force. It is this tendency to 
 combine with oxygen (forming hydrochloric acid 
 HCl) which is the essence of its use in bleaching. 
 "When brought into contact with moisture, chlo- 
 rine gradually decomposes it, forming hydro- 
 chloric acid, and setting the oxygen free. It is this 
 oxygen which exerts the bleaching action. Chlorine 
 itself is too corrosive and dangerous to use for 
 commercial purposes, except in special instances, 
 so that some of its compounds, known as hypo- 
 chlorites, are usually employed. 
 
BLEACHING 73 
 
 Bleaching Powder. 
 
 The best known of the bleaching agents which 
 have chlorine as their active constituent is chloride 
 of lime, or bleaching powder, which is made by 
 passing chlorine gas over slaked lime in brick 
 chambers, special precautions being taken to keep 
 the temperature as low as possible ; for, if the tem- 
 perature be allowed to rise, a considerable amount 
 of chlorate of lime is formed, which is quite use- 
 less for bleaching purposes, and if present in 
 large excess might possibly be dangerous. 
 
 Bleaching powder varies very much in quality, 
 the best powder being almost dry and powdery 
 and containing about 38 per cent available 
 chlorine. Poorer qualities may contain much less 
 chlorine, and are frequently quite moist and full 
 of large lumps. Solutions of bleaching powder, 
 which by the way, is a hypochlorite of lime, are 
 sometimes used in the laundry, and if employed, 
 great care must be taken to obtain a clear solution 
 free from any suspended lime. Bleaching powder 
 always contains a certain amount of free caustic 
 lime, and if this gets on to any fabric, the results 
 will be disastrous. If solution of bleaching 
 powder be employed, it must be a very weak one, 
 a 2 per cent solution being quite strong enough. 
 
 For general laundry purposes, however, it is 
 usually more convenient to employ the compound 
 
74 BLEACHING 
 
 known as hypochlorite of soda, which a launderer 
 can buy in strong solution, or make for himself 
 from bleaching powder. In the latter case, a 
 solution of ordinary washing soda or dry alkali 
 is mixed with the proper proportion of bleach- 
 ing powder previously worked up into a fine state 
 with water, condensed or distilled if possible. 
 The soda and the lime change places, forming 
 carbonate of lime and hypochlorite of soda, which 
 can be put into a tank or other suitable vessel 
 and kept for use as wanted. As, however, the 
 quantity of bleaching solution required in a 
 laundry is, or should be, very small, the launderer 
 will usually find it more convenient to buy his 
 bleaching solution ready made, as it saves him 
 a good deal of trouble. He can then dilute the 
 strong solution as he requires it. The chemical 
 way of writing sodium hydrochlorite is NaClO, 
 and when this comes in contact with any sub- 
 stance which is readily oxidizable, the compound 
 parts with its oxygen, becoming converted into 
 ordinary sodium chloride or common salt — NaCl. 
 Chlorine bleaches do not interfere with the 
 action of the soap, and the diluted bleaching solu- 
 tion may be put in the machine with the second 
 soap. It is always found that it works much 
 better after the excess of dirt and grease have 
 been removed by the first wash. The bleaching 
 should be followed by an acetic acid bath in the 
 
BLEACHING 75 
 
 second rinse, as this helps greatly to get rid of 
 any traces of bleaching material still left in the 
 goods and to improve the color. As a matter 
 of practice, the action of all chlorine bleaches is 
 fonnd to prove destructive, even to cotton fibres, 
 if used upon them much, the chemical action not 
 being really quite so simple as it is usually repre- 
 sented in text books, or for the sake of con- 
 venience in explaining matters to learners. Al- 
 though the dirt stains are first attacked by the 
 bleaching solution, this soon proceeds to attack 
 the fibres and also to oxidize them. For this 
 reason, bleaching should only be resorted to in 
 case of absolute necessity, and not as a regular 
 part of the laundry process. Most of the chlorine 
 bleaches on the market are made by passing 
 chlorine into a solution of caustic soda which is 
 kept cool to prevent the wasteful formation of 
 chlorate. 
 
 Electrolytic Bleaches. 
 
 The principle of producing a bleaching liquor 
 by electrolysis, is, by passing an electric current 
 through sea water or a solution of common salt. 
 It is only quite recently that a practical apparatus 
 has been placed upon the market. The effect of 
 the passing of the current is to break up the salt 
 into its elements sodium and chlorine. The sodium 
 reacts with the water, to produce caustic soda, 
 
ij-g BLEACHING 
 
 and the chlorine to produce hypochlorous acid, 
 HCIO. This unites more oi less with the caustic 
 soda to form sodium hypochlorite, NaClO, but 
 I am inclined to think there is always a large 
 quantity of hypochlorous acid in the free state. 
 It is the best chlorine bleaching agent, and is 
 comparatively harmless, besides being a very 
 powerful antiseptic and deodorant. 
 
 Reduction. 
 
 "While I am writing of bleaching, it would per- 
 haps be well to say a few words of the opposite 
 process. Bleaching with cUorine or with hy- 
 drogen peroxide is, as I have already explained, 
 a process of oxidation. Now while the majority 
 of natural coloring matters will yield to this 
 process and become decolorized, there are a good 
 many dyes in use upon which oxidizing compounds 
 produce little or no effect, and if it should so 
 happen that white goods become stained pink or 
 any other color through contact with fabrics dyed 
 with the substances referred to, the launderer will 
 find it quite impossible to remove the color with 
 any of the ordinary bleaching substances in gen- 
 eral use. In order to get rid of the dye he must 
 use the opposite method; instead of endeavoring 
 to give the dye more oxygen, he must take oxgyen 
 away from it, and there are two or three ways 
 of doing this. 
 
BLEACHING 77 
 
 Most launderers are more or less familiar with 
 the burnt sulphur process, used so largely for 
 blankets and straw hats. In this case the articles 
 are suspended in a chamber filled with the fumes 
 of burnt sulphur, which has exactly the opposite 
 effect to chlorine bleaches or hydrogen peroxide. 
 While these are perfectly ready and anxious to 
 part with their oxygen to any other substance 
 which wants it, burnt sulphur — known chemically 
 as sulphur dioxide or sulphurous acid — is itself 
 hungering for oxygen, and is prepared to rob any 
 other body of it where possible. 
 
 Consequently when a launderer fails to remove 
 a stain with the other bleaches he should try 
 sulphurous acid. This must not be confused with 
 sulphuric acid, which is a different substance al- 
 together. The sulphur dioxide can be obtained 
 liquefied under pressure in syphons, just like soda 
 water, and this form has its conveniences, but, 
 generally speaking, the launderer will find it 
 most convenient to make his sulphurous acid him- 
 self from sodium sulphite, which is a compound of 
 soda with sulphurous acid. If another acid, such 
 as dilute sulpuric acid be added to a solution of 
 sodium sulphite, sulphurous acid is set free. 
 Sodium sulphite can be obtained at any photo- 
 graphic dealers for a few cents a pound. After 
 the stain has been removed it is only necessary to 
 
78 BLEACHING 
 
 rinse the article in hot water, as sulphurous acid 
 is easily removed. 
 
 There is a class of substances, known as stable 
 hydrosulphites. These have a similar but better 
 action than sulphurous acid and are largely used 
 by cleaners and dyers. They go under various 
 trade names, such as hydraldite, ronalite, etc. 
 
 An even more powerful reducing agent, that is 
 to say, a substance which will take up oxygen, is 
 titanous chloride, which is sometime sold under 
 the name of ''stripping salts." Colors are dis- 
 charged by it with great rapidity, and it has no 
 injurious action on fabrics. On account of its 
 scarcity, however, this substance is very expen- 
 sive, and can only be used for removing stains or 
 doing special work. Solution of titanous chloride 
 is so useful for stain removing that it should be 
 kept in every laundry ready for emergencies. 
 
CHAPTEE VII 
 
 Stains, and Theie Removal 
 
 Judging from the queries I receive, stains and 
 their removal offer one of the most serious prob- 
 lems with which the launderer has to deal, and 
 the consideration of the subject comes in its 
 natural place after treating of the different kinds 
 of bleaching reagents. As a general rule, to 
 which, however, there are a few important excep- 
 tions, the principal difficulty, from a chemical 
 point of view, is not the removal of the stain, but 
 the finding out the nature of the stain. When 
 once this is known, the task of removal proceeds 
 on perfectly well known lines, except in those 
 cases where the stain can only be removed by re- 
 moving the fabric as well. 
 
 The first thing which should always be done 
 when a stained fabric has to be dealt with, is to 
 endeavor to ascertain the nature of the stain ; and 
 the experiments should always be conducted on a 
 small portion of the stained area, and, whenever 
 possible, on that portion which is least likely 
 to attract the attention of the observer when the 
 article is in use. What the launderer frequently 
 
 79 
 
80 STAINS, AND THEIE REMOVAL 
 
 does, is to try, first one thing and then another 
 on the whole of the fabric, instead of proceeding 
 by making little tests as just recommended. The 
 consequence of this is that if his methods are not 
 almost immediately successful, as not infrequently 
 happens, he runs the risk of doing considerable 
 damage to the fabric. 
 
 There are so many ways in which stains may oc- 
 cur, and so many different kinds of fabrics — white 
 and colored — upon which the stains may be, that 
 more often than not, the satisfactory removal of 
 a stain requires the services of an expert, pro- 
 perly-trained chemist; but by carefully following 
 out instructions, taking care to mix as much 
 brains as possible with the chemicals, there is no 
 reason why a launderer should not achieve a satis- 
 factory amount of success in dealing with stains. 
 
 For testing purposes, the launderer should 
 possess at least the following: — 
 
 Dilute hydrochloric acid, the strong, pure acid 
 diluted 1 to 10 parts of water ; hydrogen peroxide, 
 or sodium perborate — the latter for preference — 
 methylated spirit; solution of methyl orange 
 (dye); chloroform; benzine; bleaching powder; 
 sodium sulphite; potassium ferrocyanide solu- 
 tion; stripping salts. Most of these chemicals 
 are required not only for making the tests, but 
 for removing the stains also. 
 
STAINS, AND THEIE REMOVAL 81 
 
 Acids and Alkalies. 
 
 In making the tests, the first thing to do is to 
 ascertain whether the stain is acid, alkaline or 
 neutral. Dip the stained portion in a little dis- 
 tilled water in a saucer, and add one or two drops 
 of the solution of methyl orange. If the color 
 changes to yellow, alkali is present; if to red, 
 acid is there. A test can, of course, be made with 
 litmus paper, but the test just indicated is much 
 more delicate. The quantity of acid or alkali 
 discoverable in the fabric, even if it had been 
 brought in contact with considerable quantities in 
 the first instance, would probably be very small, 
 and might not seem to change the color of litmus 
 paper. The dye known as phenol-phthalein is 
 very useful as a test for alkali ; in neutral or acid 
 solutions it is quite colorless, but the least trace 
 of alkali develops a very marked rose color. If 
 it is found that acid is present, it should be re- 
 moved by ammonia or weak carbonate of soda 
 (washing soda). If the stain be alkaline, it may 
 yield to acetic acid, but in all probability it will 
 be necessary to bleach it with bleaching powder 
 solution, hypochlorite of soda, hydrogen peroxide 
 or sodium perborate, according to whether the 
 material is linen (or cotton) or wool. 
 Aniline Dyes. 
 
 If the stain be of a pink or other marked bright 
 color, it is probably due to either a fruit stain or 
 
82 STAINS, AND THEIE EEMOVAL 
 
 to an aniline dye. In the former case, it should 
 be removed by sodium perborate or bleaching 
 powder, which will also in many cases remove 
 aniline dyes. If it will not yield to this treat- 
 ment, try sulphite of soda dissolved in water, to 
 which is added some hydrochloric acid. The pro- 
 portions required would be 1 ounce of sulphite, 
 half an ounce of hydrochloric acid or oxalic acid, 
 if hydrochloric is not available, i/. gallon of water. 
 If this fails, try titanous chloride solution. As 
 a preliminary to these operations it is always well 
 in the case of pink or other stains, which appear 
 to be due to fruit or a dye, to try the effect of 
 alcohol. This will sometimes remove them by 
 itself, and in the case of fruit stains the alcohol, 
 even if it will not remove the stain, will dissolve 
 the sugar and gummy or resinous substances 
 present, and thus render the subsequent task of 
 removing the color easier. 
 
 Green Stains. 
 
 Green stains, due to leaves, will very often 
 come out with alcohol. This should be followed 
 by a little peroxide or perborate. 
 
 Chloroform is often of considerable assistance 
 in removing stains of the characters just de- 
 scribed. This used with alcohol will take out a 
 great many vegetable stains and many dyes. 
 
STAINS, AND THEIR BEMOVAL 83 
 
 Walnuts. 
 
 stains on table linen are sometimes caused by 
 walnuts, either fresh or pickled, and are due to 
 tannin. They are best destroyed by the mixture 
 of acid and sulphite of soda described above. 
 
 Photographic Stains. 
 
 Photographic stains are of a very similar char- 
 acter to those caused by walnuts, and can usually 
 be removed by the mixture of acid and sulphite. 
 Sometimes, though not often nowadays, photo- 
 graphic stains are due to silver nitrate, in which 
 case they must be treated in the same manner as 
 marking ink (which see). 
 
 Iron Stains. 
 
 Iron stains frequently trouble the launderer. 
 They may be due to various causes, the iron being 
 derived either from the water, the outer case of a 
 metal washing machine, a galvanized tank, which 
 has been allowed to go rusty, or from the steam 
 pipes, etc. More than one case has come under 
 my notice where many of the goods washed at tlie 
 beginning of the week or in a particular washing 
 machine have been badly stained with iron. This 
 was eventually traced to the condensed water in 
 the steam pipe, which had been lying over the 
 week-end and contained a considerable amount of 
 iron rust. As soon as steam was turned on, this 
 
84 STAINS, AND THEIR REMOVAL 
 
 water with the iron was blown into the washer 
 and stained the linen badly. Quite a considerable 
 proportion of the stained articles submitted to me 
 contain iron. 
 
 The test for iron is a very simple one ; the mate- 
 rial is treated with a few drops of dilute hydro- 
 chloric acid to dissolve the supposed iron (which 
 is nearly always present as oxide or hydrate) and 
 then one or two drops of solution of potassium 
 ferrocyanide are added. If iron be present, a blue 
 color (Prussian blue) will be produced. The 
 removal of iron stains is effected by means of acid. 
 If reasonably fresh, they will come out with acetic 
 acid or oxalic acid (1 in 20), but if long standing 
 and thoroughly boiled into the goods, the stains 
 are not at all easy to remove. In such a case, 
 hydrochloric acid must be resorted to, care being 
 taken to rinse out the acid as soon as it has done 
 its work. One of the advantages of the acetic acid 
 bath in the second rinse, is that it will remove any 
 fresh iron stains as well as lime, and prevent any 
 likelihood of serious trouble from this cause. 
 
 Copper Stains. 
 
 Copper stains sometimes occur in the laundry. 
 They usually consist of copper soap off some cop- 
 per vessel used in the laundry, and I had a case 
 recently of some window curtain blinds, which 
 had been washed with the brass rings on, and the 
 
STAINS, AND THEIR EEMOVAL 85 
 
 copper soap formed in the washer had stained the 
 fabric badly in the neighborhood of the rings. 
 The best way to remove it is with hydrochloric 
 acid (1 in 10) taking care to remove the acid, after 
 the stain has been destroyed, by thorough rinsing. 
 If it is not known for certain that the stain is 
 due to copper, but its presence is only suspected, 
 the best test is to dissolve a little of the stain in 
 hydrochloric acid and add a few drops of potas- 
 sium ferrocyanide ; if copper be present a reddish 
 brown precipitate, looking rather like red current 
 jelly, will be produced, or if only in very small 
 quantity, a red coloration. 
 
 Writing Ink. 
 
 Among the most common stains in a laundry are 
 those of writing ink. This liquid is made by mix- 
 ing an infusion of galls with solution of sulphate 
 of iron or green vitriol. So long as it is preserved 
 from the air, this solution is practically colorless, 
 but as it combines with oxygen, it gradually turns 
 black. The consequence of this is that the manu- 
 facturers are obliged to add a coloring matter to 
 the ink, known as a ''provisional coloring matter" 
 and this consists usually of aniline dye, from 
 which the inks derive their name of blue-black, 
 violet-black, etc., according to the nature of the 
 dye employed. AVlien the ink dries and is exposed 
 to the air jet^ black tannate of iron is formed in 
 
86 STAINS, AND THEIR EEMOVAL 
 
 the course of a day or two. A fresh ink stain can 
 almost be washed out, the remaining coloring mat- 
 ter, which consists almost entirely of the aniline 
 dye, being readily removed by solution of bleach- 
 ing powder or sodium hypochlorite, or perborate. 
 Long standing- ink stains will frequently yield to 
 this treatment also. Another method is to dis- 
 solve the stain with solution of oxalic acid (1 in 
 10) neutralizing the acid with sodium carbonate 
 (washing soda) or ammonia directly the stain 
 has been removed, to insure that any acid not 
 rinsed out shall not act upon the fibres. If any 
 iron still remains on neutralizing, a brown spot 
 will probably appear, which must be removed 
 by a further treatment with acid and again neu- 
 tralizing. The spot should always be well rinsed 
 after treatment. It should be remembered that 
 many writing inks, if allowed to remain long, have 
 a very bad effect upon the fibres and such spots 
 are always liable to go into holes. 
 
 Marking Ink (Silver). 
 
 Marking ink stains form another frequent prob- 
 lem for the launderer, and a very difficult prob- 
 lem, too. The essential portion of marking ink, 
 as in the case of the writing ink just referred to, 
 is colorless in most cases, consisting of a solution 
 of a silver compound which darkens on exposure 
 to light, forming within the fibres an insoluble 
 
\ 
 
 STAINS, AND THETK KEMOVAL 87 
 
 black pigment, and the coloring matter which is 
 present in fresh marking ink is due to suspended 
 carbon, which enables the person using it to see 
 what he is writing, the actual silver pigment ap- 
 pearing later as described. This silver pigment 
 is of a very permanent character, and very diffi- 
 cult to remove; in many cases it is practically 
 impossible to move it without destroying the fibre 
 as well. In most cases, the task of removing 
 marking ink is one of such difficulty that it can 
 only be attempted with success by an expert an- 
 alytical chemist. One method of removing mark- 
 ing ink is to treat the stain, first of all, with solu- 
 tion of iodine, which, if it acts, changes the silver 
 into iodide, and then to remove this with cyanide 
 of potassium solution. This substance is fright- 
 fully poisonous, and is dangerous "to have about 
 the house" if it can be avoided. Another method, 
 which is always a last resource, is to treat the 
 stain with strong hydrochloric acid, which con- 
 verts the silver into chloride, and to treat this 
 immediately with strong ammonia, which dissolves 
 it. In most cases marking ink stains are best left 
 alone, as attempts to eradicate them as a rule only 
 make matters worse. 
 
 Grease Stains. 
 
 Grease stains which will not come out in the 
 ordinary process of washing are best removed 
 
38 STAINS, AND THEIE REMOVAL 
 
 with carbon tetrachloride, a heavy, volatile, color- 
 less liquid, which is an excellent solvent for grease, 
 and possesses the advantage over benzine that it 
 is not inflammable. As it is much more poisonous 
 than chloroform, however, great care must be 
 taken in using it. In taking out grease stains it 
 must be remembered that candle grease nowadays, 
 except in the best candles which are made of 
 stearin or rarely of wax, consists largely or wholly 
 of paraffin, which is quite unaffected by soap and 
 water, but dissolves readily in carbon tetra- 
 chloride. 
 
 Many people in using a solvent for the removal 
 of grease take some of the liquid on a pad of 
 some material and rub the spot with it. This is 
 quite the wrong way to go to work. If the stains 
 are small in area, the best way is to place a pad 
 of blotting paper under the stained spot and drop 
 the solvent on the top. If the stain is extensive, 
 put a little of the solvent in a basin and dip the 
 stained portion of the fabric in it; then squeeze 
 it out and dip again until the stain is removed, 
 giving the spot a final rinse with some fresh, clean 
 solvent. 
 
 Paint Stains. 
 
 Paint usually consists of some insoluble color- 
 ing matter, such as barytes or umber, mixed with 
 a vegetable drying oil, usually linseed. When the 
 
STAINS, AND THEIK KEMOVAL 89 
 
 oil is exposed to the air, it *' dries," that is to say, 
 becomes oxidized into a hard varnish, which not 
 only fixes the coloring matter in its place, but acts 
 as a protective covering to the wood or iron work 
 upon which it is spread. In order to remove paint 
 stains, it is necessary to use a solvent, such as car- 
 bon tetrachloride or benzine, to dissolve this dried 
 oil. On account of the nature of the material, it is 
 necessary to rub the stain with a pad of cloth 
 dipped in the solvent. Comparatively fresh paint 
 stains come out fairly easily, but when they are 
 long standing they are not at all easy to move. 
 Strong ammonia is a distinct help in the removal 
 of paint, oil and grease stains. 
 
 In removing tar or heavy grease stains, it is a 
 great help to rub the stain with a soft fat, like 
 butter or cocoanut oil, and then remove the two 
 together with carbon tetrachloride or benzine. 
 
 Printing" Ink. 
 
 Printing ink is an oil varnish, containing lamp 
 black, or some other coloring matter, and must be 
 treated in the same way as an ordinary oil paint. 
 
 Blood and Albuminous Stains. 
 
 Blood and albuminous stains, that is to say all 
 stains from the human bod}^, are removed in much 
 the same manner, namely, by soaking in cold or 
 very lukewarm water with a little weak alkali. 
 
90 STAINS, AND THEIR EEMOVAL 
 
 Albumen is coagulated by heat at quite a mod- 
 erate temperature, and when once it has reached 
 this stage it is not at all easy to remove. The 
 yellow stains which frequently appear on collars 
 and cuffs are due to rubbing against the skin, and 
 are of an albuminous nature. Where they have 
 been boiled into the linen the only way to remove 
 them is by bleaching with a hypochlorite. Strong- 
 ammonia is of great assistance in removing all 
 stains of this nature. Blood stains due to venous 
 blood usually come away quite easily by soaking 
 in tepid water with ammonia or other alkali, but 
 arterial blood appears to form some compound 
 with the fibres, and is much more difficult to re- 
 move. Ammonia is the best solvent, and even 
 obstinate blood stains can usually be removed by 
 prolonged treatment, followed by a little oxalic 
 acid and thorough rinsing. Old blood stains, 
 whether venous or arterial, require prolonged 
 soaking in water before any other treatment is 
 applied. 
 
CHAPTER VIII 
 
 Solvents 
 
 I now come to the consideration of the various 
 solvents used in the laundry and cleaning and 
 dyeing industries. The most important is natur- 
 ally water, in regard to which I must point out in 
 passing that its solvent powers increase rapidly 
 with its purity. Consequently, soft water is far 
 better for all cleaning purposes than hard water. 
 It is, however, with the other solvents that I wish 
 to deal now. With the exception of benzine and 
 solvent naphtha, solvents other than water are 
 only used in very small quantities for the local 
 treatment of spots and stains, and among them 
 may be included alcohol, ether, chloroform, carbon 
 tetrachloride, carbon bisulphide, turpentine and 
 other essential oils. 
 
 Benzine. 
 
 In the first place, benzine must not be con- 
 founded with benzene. The former is obtained 
 from petroleum, and the latter from coal tar oil. 
 Benzine, which is also known as petrol, benzoline, 
 petroleum spirit and petroleum ether, is obtained 
 
 91 
 
92 SOLVENTS 
 
 by the distillation of crude petroleum. This sub- 
 stance, obtained from oil wells in America, the 
 Caucasus, Borneo, and other parts of the earth, 
 consists mainly of a series of very similar com- 
 pounds called paraffins, of which methane, or 
 marsh gas, is the lowest term. The composition 
 of this is one particle of carbon combined with 
 four of hydrogen, and every step up the series is 
 made by substituting one atom of carbon com- 
 bined with three of hydrogen for one particle of 
 hydrogen, thus: — 
 
 CH4 methane. 
 
 CH3— CH3 ... ethane 
 
 CH3— CH,— CH3 propane. 
 
 CH3— CH,— CH,— CH3 . . . butane. 
 
 CH3— CH3— CH,— CH,— CH3 pentane. 
 
 and so on, as simple as A B C. 
 
 Different Paraffins. 
 
 All the different products of petroleum in the 
 market are mixtures of these substances. The 
 lowest, such as methane, are gaseous, and are 
 found in abundance in the gases given off from 
 the petroleum wells; next come the very light 
 volatile oils, such as petrol and benzine, then the 
 burning oils used in the household lamps, then 
 solar distillates used in gas works to enrich coal 
 gas, then the lubricating oils and vaseline, and 
 
SOLVENTS 93 
 
 lastly, solid paraffin wax. These are all contained 
 in the crude petroleum, and are separated from 
 one another by distillation in the same way that 
 whisky is separated from water. Each fraction, 
 as it is called, however, does not consist of one 
 paraffin only, but of several, generally four or five. 
 Consequently, if we warm benzine, for example, 
 the lowest of the series which happens to be pres- 
 ent will begin to volatilize, although it may be 
 there in comparatively very small quantity, and 
 the point of volatilization of the next one present 
 may be very much higher. This vapor, with the 
 air, will form an explosive mixture, and if it 
 comes in contact with a light will explode and fire 
 back, and set the whole of the benzine alight. This 
 shows the reason for the elaborate precautions 
 employed in dry cleaning work, and the necessity 
 for the greatest care to be observed by any laun- 
 derer employing small quantities of benzine for 
 any purpose in the laundry. 
 
 It must be remembered that, in spite of its vola- 
 tility, benzine vapor is much heavier than air, and 
 will travel along the bench or the floor for several 
 feet, and if a light happens to be at that distance 
 away a catastrophe is almost inevitable. As an 
 illustration of this, I remember an accident which 
 occurred some years ago in a works where I was 
 engaged at the time. Some workmen were told 
 by the manager to empty a cask containing a 
 
94 SOLVENTS 
 
 gallon or two of heavy oil residues, and they pro- 
 ceeded to empty it into the coke about ten feet or 
 more away from the boiler fire. The vapor in 
 the cask, however, traveled to the fire, and a seri- 
 ous explosion resulted. 
 
 Sulphur Compounds. 
 
 Among the other hydrocarbons contained in the 
 crude petroleum, for it does not consist entirely 
 of the paraffins, are a certain proportion of sul- 
 phur compounds, some of which, like thiophene 
 (C4 H4 S) are well known, but there are a number 
 of others not so clearly defined, and it is to these 
 that the unpleasant smell is due. Benzine which 
 has been thoroughly purified from sulphur com- 
 pounds has a much more ethereal odor than the 
 liquid in common use. The smell which remains 
 in the goods after the dry cleaning process, is 
 caused by the more heavy of these sulphur com- 
 pounds, which remain in the goods, and require 
 long *'stoving" to drive them off. 
 
 Solvent Action of Benzine. 
 
 Benzine is an excellent solvent for all oils and 
 fats, and as a good deal of dirt is attached to the 
 fibres of garments by means of grease, a consider- 
 able proportion of it will come away as soon as 
 the grease is removed by the benzine. Where it 
 is necessary to deal with specially dirty garments, 
 
SOLVENTS 95 
 
 or portions of garments, in the dry cleaning 
 process, it is necessary to employ an anhydrous 
 soap, that is to say, a soap which is very nearly 
 free from water. Benzine is sometimes added in 
 small quantities to soap used for ordinary wet 
 washing, and some launderers make a practice, 
 with very dirty loads, of adding a pint or so of 
 benzine to the first wash. Benzine used in this 
 way does certainly assist considerably in cleans- 
 ing, not probably so much by dissolving grease as 
 by increasing the surface action of the soap. 
 There is a certain amount of danger in using ben- 
 zine in this way, as a case occurred not long ago, 
 when the vapor issuing from the gland of the 
 machine caught fire. 
 
 Benzene. 
 
 Benzene, benzole, and solvent naphtha are all 
 names for the light tar oil obtained from the tar 
 produced in gas-making by subsequent distillation 
 of the oil. Commercial benzene contains other 
 substances besides that known chemically as ben- 
 zene, such as toluene and xylene, although this 
 does not affect to any extent its usefulness for 
 cleaning purposes. Benzene is quite as good a 
 solvent as benzine, and the reason why it is not 
 used much for cleaning purposes is on account of 
 its increased cost. Benzene, and other substances 
 of the same order, found in coal-tar oil, form the 
 
96 
 
 SOLVENTS 
 
 starting-point of nearly all the dyes used in mod- 
 ern industrial operations. 
 
 Alcohol. 
 
 Alcohol is a good solvent for sugar, and many 
 stains of an organic nature caused by fruit, grass, 
 or leaves, the alcohol dissolving the resinous mat- 
 ter which frequently accompanies them and ren- 
 ders then difficult to remove. Generally speaking, 
 however, ether is better for removing green stains 
 caused by grass or leaves. Fresh ink stains will 
 frequently yield to alcohol. For the benefit of 
 those who are interested in the chemistry of the 
 different substances they are using, I may remark 
 that an alcohol is a hydrate of a hydrocarbon, in 
 almost the same way that sodium hydrate is a 
 hydrate of sodium. 
 
 CH4 
 
 methane. 
 
 Na. OH ... 
 
 sodium hydrate. 
 
 CH3 OH . . . 
 
 methyl alcohol. 
 
 C.He ... . 
 
 ethane. 
 
 C.H5OH... 
 
 ethyl alcohol 
 
 
 (ordinary alcohol) 
 
 Amyl Alcohol, Glycerine and Ether. 
 
 Besides these alcohols, there are several others, 
 known as the "higher alcohols," all formed on 
 exactly the same plan. One of them is amyl alco- 
 
SOLVENTS 9Y 
 
 hol, which is sometimes used for removing spots. 
 Another alcohol of a rather different kind is gly- 
 cerine, which, combined with fatty acids of differ- 
 ent kinds, forms the whole of our oils and fats. 
 Ether stands in the same position to alcohol as 
 sodium oxide does to sodium hydrate. It forms an 
 excellent solvent for oils and fats, and is largely 
 used for this purpose in the laboratory. It is, 
 however, extremely volatile. Ether is very useful 
 for dissolving stains caused by leaves and fruit 
 juices, being better than alcohol for this purpose. 
 One drawback to the use of ether is its extreme 
 volatility. 
 
 Carbon Tetrachloride. 
 
 Carbon tetrachloride is an excellent solvent for 
 fats, and possesses the advantage of being non- 
 inflammable; in fact it forms a very good fire- 
 extinguisher. It is, however, more volatile than 
 benzine; consequently in a mixture of carbon 
 tetrachloride and benzine, the former, when the 
 mixture is exposed to the air, evaporates first, and 
 the proportion of benzine gets higher and higher 
 until the mixture consists practically entirely of 
 benzine. The notion, therefore, that a mixture of 
 carbon tetrachloride and benzine can be safely 
 considered non-inflammable is fallacious. Carbon 
 tetrachloride is very similar in composition to 
 
98 SOLVENTS 
 
 methane, consisting, as its name indicates, of one 
 atom of carbon united to four of chlorine, thus : — 
 
 cn. 
 
 methane. 
 
 CCI4 
 
 carbon tetrachloride. 
 
 CHCI3 
 
 chloroform. 
 
 The drawback to its general use is that it is 
 distinctly poisonous. 
 
 Chloroform, Turpentine and Carbon Bisulphide. 
 
 Chloroform belongs to the same series as car- 
 bon tetrachloride, and is three parts of the way 
 between methane and the last-named substance. 
 It is a very powerful solvent, dissolving fats and 
 oils with ease. It forms also an excellent solvent 
 for many dyes. Turpentine, which is obtained by 
 distilling the juice that exudes from certain pine- 
 trees when an incision is made in the stem, is the 
 type of all essential oils. These substances are 
 found in varying but usually very minute quanti- 
 ties in flowers and other parts of plants. They 
 usually have a very pleasant and powerful odor, 
 and possess strong solvent properties for oily and 
 waxy matters. Carbon disulphide is used as little 
 as possible on account of its very unpleasant smell. 
 It is a very good solvent for fats and oils, and 
 sulphur dissolves in it very readily. It forms also 
 one of the best solvents for india-rubber. 
 
CHAPTER IX 
 
 Stakches and Other Stiffening Agents 
 
 Cr3rstalloids and Colloids. 
 
 I must now say a few words about two impor- 
 tant groups of substances which are distinguished 
 in chemistry by the names of crystalloids and col- 
 loids. My readers so far have only been intro- 
 duced to the former in earlier chapters, but I shall 
 now have to consider the latter class also. Salt, 
 soda, borax and sugar are good examples of crys- 
 talloids; while starch, glue, and animal mem- 
 branes are examples of colloids. Crystalloids 
 form definite crystals when a solution containing 
 them is concentrated ; and these crystals, although 
 they may differ in size and even to some extent in 
 shape, always present definite angles, and these 
 angles are always the same for the same sub- 
 stance. They are soluble in water in the true 
 sense of the term and readily diffuse through ani- 
 mal membranes ; that is to say, if a bladder partly 
 filled with a solution of common salt, for example, 
 be floated on clean water, the salt will ** diffuse" 
 
 99 
 
100 STARCHES AND STIFFENING AGENTS 
 
 through the bladder into the water outside until 
 the strength of the salt in the water and in the 
 solution in the bladder is the same. Colloids, on 
 the other hand, such as gelatine and starch, do 
 not dissolve in water in the proper sense of the 
 term, they only absorb it or mix with it, and when 
 the water is evaporated off they do not crystallize. 
 In some cases where they appear to do so, micro- 
 scopical examination shows that these are not 
 really crystals. Then again, they possess none 
 of the properties of diffusion, such as crystalloids 
 have, and if, for example, a starch paste were to 
 be placed in a bladder and floated on water as in 
 the last experiment, the starch would still remain 
 in the bladder for as long as you like to leave it 
 floating. 
 
 Starches. 
 
 Starch is a typical colloid; it mixes with or 
 swells up in water, does not form crystals, and 
 even the so-called soluble starches are not soluble 
 in the same sense that common salt is soluble. 
 Starch grains, which are obtained from the seeds 
 or roots of plants, possess, as a rule, very charac- 
 teristic shapes, but these forms do not grow in the 
 same way that a crystal does, but layer by layer 
 like the bricks on a wall. All starches possess the 
 same chemical composition, but probably the in- 
 ternal arrangement of the particles of which they 
 
STARCHES AND STIFFENING AGENTS IQl 
 
 are made up varies in some way, so that, although 
 their percentage composition is the same, their 
 mechanical properties differ a good deal, as every 
 launderer knows. It must, however, be perfectly 
 clearly understood that these are not chemical 
 differences, as we understand the word at present, 
 but mechanical ones. When once a starch is dis- 
 solved or mixed with water, its structure is 
 changed in some way, and it is not possible to get 
 back the original starch grains if the water is 
 driven off, only a horny mass remaining behind, 
 which in most cases, at all events, will not re- 
 dissolve. 
 
 Forms of Starch Granules. 
 
 On the following pages are illustrated the forms 
 as they appear under the microscope of the prin- 
 cipal starches used in the laundry industry. As will 
 be seen, they are very characteristic and differ 
 considerably from one another both in size and 
 shape. Potato starch, or farina, as it is frequently 
 termed in the laundry industry, is the largest of 
 all the starches, and rice starch is the smallest. 
 The manner of growth of the starch granule is 
 very well shown in the case of potato starch. In 
 every granule will be found a spot or hilum 
 whence the growth starts, and the starch is piled 
 on this layer on layer. In maize starch the hilum 
 shows as a cross, and in rice starch the hilum, if 
 
102 STARCHES AND STIFFENING AGENTS 
 
 present, is too small to be noticeable. The gran- 
 ules in sago starch are large, although somewhat 
 smaller than potato starch granules. In making 
 the drawing from the microscope, I think I have 
 drawn them just a little larger than they really 
 are. "Wheat starch consists of a number of more 
 or less circular granules of comparatively large 
 size, as well as a number of tiny ones. 
 
 Properties of Starch. 
 
 Each granule of starch appears to be inclosed 
 in an envelope composed of substance known as 
 starch cellulose, which very closely resembles the 
 starch substance composing the mass of the gran- 
 ule. If the starch is placed in cold water, it does 
 not dissolve unless this outer protective covering 
 is broken. The granule will absorb water and 
 swell up, but will not distribute itself through the 
 water at all. If, however, the granules are crushed 
 so as to break this envelope, the contents swell 
 very much, and by repeated washing with cold 
 water the whole of the interior can be dissolved, 
 leaving the envelope behind. The main substance 
 of the starch is colored blue by a solution of iodine 
 in potassium iodide; while the envelopes are col- 
 ored a dull yellow by the same reagent. If boiled 
 in water, however, the starch cellulose is con- 
 verted into ordinary soluble starch. 
 
STARCHES AND STIFFENING AGENTS 103 
 
 Gelatinized Starch. 
 
 As every launderer knows, a remarkable change 
 occurs when raw starch is heated in water; the 
 granules swell up and burst, and the starch matter 
 soon becomes evenly distributed through the water 
 as a gelatinous mass. This paste can be diluted 
 
 Potato Stakch (Faeina). 
 
 by adding more water, and the starch, if properly 
 mixed, will still remain evenly distributed through 
 the solution, which simply becomes thinner in 
 proportion to the dilution. If a few drops of solu- 
 tion of iodine in potassium iodide be added, the 
 deep blue color, already referred to, is produced, 
 and this forms a most delicate test for the pres- 
 ence of starch. Some starches offer a much 
 greater resistance to the gelatinizing action of hot 
 
104 
 
 STARCHES AND STIFFENING AGENTS 
 
 water than others, rich starch being much the 
 most resistant. According to one observer, the 
 following are the temperatures at which gela- 
 tinization occurs for the different kinds of 
 starches : — 
 
 starch. 
 
 Potato (Farina) 
 
 Wheat 
 
 Maize 
 
 Eice 
 
 Temperature at which 
 gelatinization occurs. 
 
 149 deg. Fahr. 
 158 „ „ 
 ■167 „ 
 194 „ 
 
 The different granules in the same sample of 
 starch do not break up all at once, those most 
 newly formed going first, while the oldest are the 
 most resistant. The following are the tempera- 
 tures at which the most resistant granules gela- 
 tinize : — 
 
 starch. 
 
 Temperature. 
 
 Potato (Farina) 
 
 . 149 deg. Fahr 
 
 Wheat 
 
 158 „ „ 
 
 Sago 
 
 • 165 „ „ 
 
 Maize 
 
 . 171 „ 
 
 Rice 
 
 . 194 „ 
 
 Starch Paste. 
 
 
 In its natural position in the plant, starch repre- 
 sents stored up energy, ready for use when the 
 young growing plant requires it, and one of the 
 
STAECHES AND STIFFENING AGENTS 105 
 
 first things that happens when a seed germinates 
 is for the starch to be converted, by means of a 
 ferment called diastase, into sugar, which the plant 
 uses partly as a building material and partly as 
 fuel, so to speak, to supply the energy required for 
 cell formation. The sugar being soluble can be 
 transferred at once in the juices of the plant to 
 where it is required. The stages through which 
 the starch passes are first soluble starch, then two 
 or three different forms of dextrin, and then 
 sugar. When barley is moistened and kept in a 
 warm place, as it is in a malt house, the embryo 
 plant in the seed immediately begins to grow, 
 sending out a miniature stem and rootlet and at 
 the same time producing diastase which acts upon 
 the starch in the manner just described. If some 
 malt extract, which contains diastase, be mixed 
 with starch paste, the changes which take place 
 can be readily followed by taking samples at in- 
 tervals of say five or ten minutes, and testing 
 them with a drop of iodine dissolved in potassium 
 iodide. At first the starch gives the well-known 
 deep blue color with the iodine; then this color 
 changes to brown as the starch is converted into 
 dextrin, and finally no color is produced on adding 
 iodine, the complete change into sugar having 
 taken place. Dextrin, by the way, is made on the 
 commercial scale by baking starch in an oven, and 
 
106 STARCHES AND STIFFENING AGENTS 
 
 is used for such purposes as coating the backs of 
 postage stamps. 
 
 Malt Extract and Diastaf or. 
 
 Some launderers use malt extract for dissolv- 
 ing the old starch out of the shirts and collars, 
 the diastase in the malt converting the starch into 
 sugar which dissolves in the breakdown water and 
 is thus easily removed. When the old starch 
 comes away, most of the dirt and yellow stains 
 come with it, so that the washing process then 
 becomes quite easy. There is no reason whatever 
 why this process should not be a regular part of 
 the washroom system. The action of ferments, or 
 enzymes, as they are called, such as diastase, are 
 not thoroughly understood. They are capable of 
 promoting such an action as the union of starch 
 and water in enormous quantities, quite out of 
 proportion to their own mass. 
 
 Starch paste made in the ordinary way consists 
 of a mixture of starch and what is known as 
 soluble starch. This material is thrown out of 
 solution, if mixed with alcohol, as a white powder, 
 but under the microscope it can be seen that, like 
 unaltered starch, it consists of small granules 
 without any structure. The amount of soluble 
 starch in the paste in the ordinary way depends 
 a good deal upon the length of time the starch 
 has been boiled; and that is one reason why, in 
 
STARCHES AND STIFFENING AGENTS 107 
 
 working the boiled starch process, good results 
 depend so much upon accuracy of manipulation. 
 It will be obvious, also, from the previous descrip- 
 tion of the modifications through which the starch 
 passes, that very important changes must take 
 place in the boiled starch when the goods are sub- 
 jected to the high temperature of the drying room. 
 
 The Viscosity of Starch. 
 
 The proportion of soluble starch to ordinary 
 starch in starch paste varies not only with the dif- 
 ferent forms of starch, but with the process of 
 manufacture and also the viscosity of the starch 
 varies as well. It is necessary to free the crude 
 starch from albuminous matter; and this is done 
 either by treatment with dilute alkali and acid or 
 by fermentation, and the properties of the starch 
 obtained by the two methods vary considerably. 
 The methods used in drying the starch have an 
 even more important influence upon its character, 
 as the following experiments will show: — 
 
 Starch No. 1 was dried while very moist at 122 
 deg. Fahr. and afterwards dried at 212 deg. Fahr. 
 for 24 hours. 
 
 Starch No. 2 was dried while very moist, under 
 reduced pressure, at the ordinary temperature of 
 the air and then for 24 hours at 212 deg. Fahr. 
 
 Starch No. 3 was dried at a reduced pressure 
 and finished at a temperature below 86 deg. Fahr. 
 
108 
 
 STAKCHES AND STIFFENING AGENTS 
 
 Comparing them by finding what weight was 
 required to make a small disc of glass sink through 
 the paste, and taking the viscosity of No. 1 as 1.0, 
 the relative viscosity was : — 
 
 No. 1. 
 No. 2. 
 No. 3. 
 
 1,000 
 2,306 
 3,288 
 
 Wheat Stakch. 
 
 The Manufacture of Starch. 
 
 The starch granules, as they are formed in the 
 cells of the plants, lie embedded in the proteid 
 matter of the cell, as well as entangled in the net- 
 work of the cells themselves, and the principal 
 problem in the manufacture of starch is to free the 
 
STARCHES AND STIFFENING AGENTS 109 
 
 granules from the glutinous and cellular matter 
 with which they are mixed. 
 
 With some starches, this is a comparatively 
 easy matter, but with others — notably rice starch 
 — the problem presents considerable difficulties. 
 In the first instance, the starch grains are washed 
 out of the cellular matter by water and are then 
 freed from adhering foreign matter either by fer- 
 mentation or by the action of alkalies and acids. 
 
 Potato starch is the easiest of all to prepare, as 
 the grains come away so freely from the cellular 
 entanglement; the tubers are first washed, then 
 rasped by machinery, and the pulp is subjected to 
 various washing processes to remove the granules 
 from the cells. 
 
 In preparing wheat starch, the grain is first 
 separated by fermentation or by Martin's process, 
 in which the starch granules are washed away 
 from the gluten. 
 
 In the case of maize starch, the grain is softened 
 with water and fermentation is allowed to com- 
 mence before it is ground ; or, by another method, 
 the fermentation is omitted and hot water is em- 
 ployed. The pulp thus formed is washed through 
 sieves, which permit the grains to pass through, 
 while the albuminous matter is retained. 
 
 Sago is obtained from the pith of a palm tree, 
 which is felled and cut up into lengths, from 
 which the pith is extracted, the starch being re- 
 
110 STARCHES AND STIFFENING AGENTS 
 
 moved simply by washing. This product is known 
 as sago flour and is subsequently purified after 
 importation into this country. 
 
 Sago Starch. 
 
 Rice starch, the most important of all the 
 starches from the launderer's point of view, is, as 
 already stated, by far the most troublesome to 
 free from glutinous matter and it is necessary to 
 employ caustic soda for the purpose, either with 
 or without fermentation. 
 
 Attention has already been called to the impor- 
 tant influence of the temperature and other con- 
 ditions on the drying of the starch. In many 
 starches, considerable loss occurs through the 
 
STAECHES AND STIFFENING AGENTS m 
 
 formation of dextrin on the outside of the masses 
 of the starch. 
 
 Action of Alkali and Acid on Starch. 
 
 Diluted alkali is without action on the starch, 
 but if any be present in starch paste it helps to 
 clear the solution by dissolving the starch cellu- 
 lose it causes no alteration in the viscosity of the 
 
 EiCE Starch. 
 
 starch. If the alkali be neutralized with acid, the 
 starch still remains transparent, while the vis- 
 cosity is unaltered. If, however, a slight excess 
 of acid be added and the starch paste be boiled, it 
 is gradually converted into sugar. Dilute am- 
 monia has no action on starch or starch paste, but 
 strong ammonia acting upon starch for several 
 
113 STAECHES AND STIFFENING AGENTS 
 
 days converts it into soluble starch. Strong 
 alkalis cause raw starch granules to swell up, and, 
 as in the case of gelatinization, potato starch is 
 the most readily attacked, while rice starch is the 
 most resistant. If raw potato starch be treated 
 with dilute hydrochloric acid for some days, it 
 is converted direct into soluble starch without go- 
 
 Maize (Coen) Starch. 
 
 ing through the paste stage. Glycerine dissolves 
 starch completely. 
 
 Lime has a curious effect on starch, entering 
 into some kind of combination, and when in this 
 state, the starch cannot be detected by any of the 
 usual chemical tests, iodine showing no blue color. 
 Consequently, starch should always be made up 
 with softened or condensed water. 
 
STAECHES AND STIFFENING AGENTS 113 
 
 Thick and Thin Boiling Starches. 
 
 When ordinary ''thick boiling," that is to say 
 unaltered, starch is acted upon by acid, important 
 changes take place ; resulting ultimately, as stated 
 above, in the formation of sugar. The interme- 
 diate stages, however, deserve careful attention 
 from the launderer. The chemical difference be- 
 tween starch and sugar is the addition of water 
 to the starch group of atoms. 
 
 Starch. Grape Sugar. 
 
 The first action of the acid is to hydrolyze, that 
 is to say, to add water to the starch cellulose 
 forming the outer coating of the starch granule ; 
 the next important step is the formation of dex- 
 trin, the intermediate product between starch and 
 sugar; and, finally, sugar itself. As the conver- 
 sion gradually takes place, the starch paste gets 
 thinner, until finally it is converted completely 
 into a crystalline substance, and the solution be- 
 comes perfectly clear. By regulating the propor- 
 tion and action of the acid, the process can be 
 stopped at any required stage. 
 
 The old way of making thin boiling starch was 
 to add a considerable amount of acid, and when 
 its action had gone far enough, to remove it by 
 washing the starch. The present method, how- 
 ever, is to add a very little acid, and when its 
 
Ill sr\Krill's AXP SIMKI'KNINU AOVINTS 
 
 ju'tion is IuusIuhI, to iumiI i ali.'.r il with l>oin\ o\' 
 soiiit' t'tlu'f nlk.'ili. riu> siisixMult'd ^^t;l^^•ll is 
 luixtul Nvilli 0:.' lo 0.\ juM- cont oi' nritl, usiinlly 
 sulplunii' ju'iil ; (lu* limrul portion is rtMUo\t>(l l>y 
 Jillowins;" tho stnr>li to s(>|lli> coiit liriii-vnlly, niul 
 tlion lu>;itt>il at about lol^ " l''alii'. until a si>lnfion {\\' 
 (lu> starrli lu'i'onios sntVicuMilly thin. 'Tlu' acid 
 is tluMi noutiali/.tui and tlu> stan'li driod. l\v vary- 
 iui; tho I'oiuiitious, thin hoiliiif;' starches can ho 
 ohtainod, \ai\in;-v Iroin ordinai'v thin hoiliiii;' 
 stavi'h us(>il at \\\c iM\>i>ortion ot" I Ih. to I'-. Ihs. 
 ju>r ^alK^n ol" watiM', u|> to thin hoiliii!'; stafi'iu>s in 
 Nvliii'h as inui'h as o \o (i Ihs. por !.';idUMi still !.;i\t>s n 
 oloar si^lution. 
 
 Aootiitea of Ci'lluloso ntnl Feculoso. 
 
 (\»llnlos<> (MitiMs into sovmal oonihiiiations willi 
 nt't^tio JU'id to t'oiiu aciMatos, (>itlh>r by llu* ncliou 
 o[' iiiai'ial ni't^tii' acid or act'lyl chlotitlt*. (\>llnloso 
 tctia acetate is a lu>antil"ul produt-t, and lihns dt>- 
 posi(t>d friMU a si>lnti(ni in chlorot'oiin ari> nu>st 
 brilliant, ciWi>rl(\ss and very strmii;-. 'Tluvsc prod- 
 ucts arc tindiujv ('i>nsidtM'abh» application now in 
 the ninnuf;utnre ot" artitii'ial silk. Tlu^v slu>uUl bo 
 watihcd by laundeitMs with cart', (hie (>!" the cel- 
 lulose acetate pnuincts is now on tht> I'ritish tnar- 
 kci luider the nanuMW' *• l\H'ulost\" It is obtained 
 by till' partial acti^ni ot" s-vlacial ai'etie acid on 
 start'li; and. owiui;' to the I'learmvss and brilliaui'y 
 
of iUti i]\m it tUipoHiih ttu fn^fnun, t*M[n*/'4Si\\y t'/Aori'A 
 orutHf with wiiU'}i H \n brought Jw t'/fuUuitf it bJ/J« 
 fair to f>'; of pfHi/'it H^irvj/^j i/} iU*i ihun'Jiry UuluHiry, 
 
 Olh<:r Hlitft'jiini^ Ag90U, 
 
 J/j a'j'ijtion lo Hitif't'hf mvi*,rii\ <fihitr <'/>lloid, th;it 
 iM to ««y, glu'fy n\i\>niiiJi<'A*M urn u«<'/i uj^oo fh\/rU'M 
 f/> 'nfipuri Hi'iffnttiiH to ihi'tt^. Onlioary irt'-lai'iu \v> 
 nm*A f<>ti>'uU',ni\>\y for aiU'fcjnni/^ KJJk« an/J iU^firyf 
 HH (fr'Vitmry i^Xnrch tnakitH hucU ahAcU'M U>o HiMf on 
 Ifj'i one. Ir.iii'i uti'i hii¥, a U:rnUmf^y t') f^W*i h rm«ty, 
 hfooy Hurftu'tt on tint oiSntr. (UtUii'in and homf, of 
 y\iit '/utsi-n }ir<t U!-;o'J iri ;•;!';« '1. 
 
 A HortiiiwUni rcjn'firkn^Ait produH obtain^^'i frorr) 
 fb^i Io''U«t b'^arj, corooioo io <'<>ufiir\<'M U>r'i<;rJoj< 
 oo tho Mttti'dt'.rrsint'nn and la r'/fly uh*'/\ aw tfio 
 bawJH of r/joftt of Ib^; pnU'jti food« for cattU; an/l 
 horw;«, j« now tiiinudinw, prr<;al tiiUini'ioii. An <',X' 
 oA*At(\\ni^\y UfUi^li ytWy knov/n a» '^j^urrj irnu^nhtA** 
 'i¥> o\Am\ui'A from lb<; k<;rrj<J of th<^w U?afjK, arj/J, 
 o'\i\i<'T alone, or <;(H(M\n*'A wjlh Hiar<'}i^ i« a)r<ja/Jy 
 on th^; ruarkoX for \a\nAry pwrptmttn. Th'th i^nm in 
 tixiraord'niiirWy tf^up^h and pJiabJ^j, an/i can U< a^'j'l 
 (ihhitr \fy ]Ut',\f or in ^combination with «tarcb or 
 with w<?iprhtinpr a'//'.niii, nwli an t-U'ina (•,\ay, for till- 
 ing or Ktr<inglh<?ning fa\>r\('M, \i ;-;<f'?rn« tf> U; 'juit<j 
 an WiiaJ Htilthiancji U) M^t for i.a\j\ti lUtfji :).n'i 
 
116 STARCHES AND STIFFENING AGENTS 
 
 napery; while for delicate articles, such as mus- 
 lins and similar finery, it should prove very valua- 
 ble for stiffening them without destroying their 
 pliability. 
 
 Borax in Starch. 
 
 As borax is so frequently used in starch, it 
 would not be out of place to say something further 
 about it here (see also page 38). It has often puz- 
 zled me why launderers use it at all in their starch 
 except to neutralize any lime which may be pres- 
 ent in .the water employed for making up the 
 starch. As far as I am aware, it can serve no 
 other purpose, except possibly to keep the iron 
 from sticking. In the first place, soft water should 
 always be employed wherever possible for starch- 
 ing, and especially for making up the starch in 
 the first instance before diluting. In the second 
 place I feel sure that even if it be an assistance, 
 launderers use a very great deal too much borax, 
 and this excess of borax in the starch is the cause 
 of many of their troubles, especially the cracking 
 of collars. 
 
CHAPTER X 
 
 Fuels 
 
 Considering what a very important item the 
 fuel bill is in the laundry, it is well worth the while 
 of the launderer to get a thorough understanding 
 of the nature of fuel and combustion. In the first 
 place, the only portions of the fuel, of whatever 
 kind it may be, which are combustible and there- 
 fore useful for producing heat, are carbon and 
 hydrogen, and their combinations with one an- 
 other. In the process of combustion, the carbon 
 and hydrogen enter into chemical combination 
 with the oxygen of the air, a large part of the 
 chemical energy which runs down, so to speak, 
 being converted into heat. The hydrogen burns 
 into water and the carbon into carbonic acid gas. 
 The heat of combination of the hydrogen with the 
 oxygen is more than four times as much as that 
 of carbon, weight for weight, but as hydrogen in 
 the gaseous form is only one-twelfth of the weight 
 of carbon, a gas rich in carbon, such as good coal 
 gas, is far more valuable as a fuel in, say, the 
 gas engine, than a gas which contains a much 
 
 117 
 
IIS KUI0L8 
 
 larger propoitioii of hydrogen. I will, however, 
 refer to the (lilferent varieties of gaaeous fuel 
 later. 
 
 Carbonic Acid and Carbon Monoxide. 
 
 Il>(lr(>,t;<'ii Itiiiiis direct into watei- strai^'ht away 
 without any iidcriiKMJialc sla^^c, and if a cold piece 
 of inclal, foi- example, he placed I'oi- a lew seconds 
 «)\'ei- a nas llanie, it will he found covered with 
 littlt! drops of water, ('aihon, however, hums in 
 two stages, foi'inin^' a conihination of one part of 
 carhon lo one part of oxygen — carbon monoxide 
 or carbonic oxide ((*()), and (hen a second com- 
 p()nnd of one ))art of carbon to two of oxygen — 
 carbon dioxide Oi* carbonic acid gas (COa). The 
 former is exceedingly ])oisonous, as it enters into 
 combination with the red coloring matter of the 
 blood, even if i)resent in the air in only small 
 (pumtity, and the blood is conseqnently nnable to 
 take np oxygen. Moi-eover, in cases of i)artial 
 poisoning with carbon monoxi(h>, the blood takes 
 a long time to get back to its normal condition. 
 To breathe air containing a considerable propor- 
 tion of carbon monoxide for any length of time 
 means almost certain death from snffocation, and 
 it is this gas remaining in the passages of a coal 
 mine after a gas explosion which usually causes 
 far more deaths than the actual explosion itself. 
 
FUEL8 119 
 
 The Dangers of Carbon Monoxide. 
 
 From ihJH the r(in<htv wilJ ,s<Mf i\\it irriportfinw of 
 Hiof)f>inpf at once any loakn of gaw^ }jow<!V<;r H/rjal), 
 an<i of carrying away }>y mcann of oSimant ventila- 
 tion, or in Horno Hpecial nj;jnn<ir, thfi hiirnt u^nHdH 
 from p^'iiH ironn and gaK-}j<;ai<i<J ironing ujacljineH, 
 for it niiJHt fx; nol<;<J tliat coaJ g.-iH oont'ji/JH from 
 H \)('.r ci'.ni. io 12 f>(;r <'<fni. of carhoii inonoxJ<J<f. 
 'Vo h.'ibitually brcatho air containing avau a very 
 himall anioiifjt of carljon monoxide caujscH chronic 
 h(;a(iac}i(;H and general J(jw(iring of IjeaJtii, ho ttiat 
 if it in only for the Hake of keeping the workers 
 efficient, thin matter kIiouM receive careful 
 attention. 
 
 The CompoKition of Coal. 
 
 I liav(; alr<;ady n;lerr(;d to Home of the c/nn- 
 poundn of carhon an<i hydrogen known an the par- 
 affmn, although thin in only '>n<t nerii^H out of 
 many. NevertheleHH, ordinary paraflin oil, which, 
 an J have stated in a previoun chaj^ter, in a mix- 
 ture of many ''[iaraffinH," will Hcrva aH an exam- 
 ple to commence with. If a nnjall <jijantity of 
 paraffin oil l><; thrown u[>on a Ijot fjre, part of it 
 will hiirnt into fianje, while another part will be 
 brok(;n up by tlie heat, a large amount of Koot 
 being net free. Now thin ih exactly what happeuH 
 when a bitumiaouH or **ga«Hy" coal i8 thrown 
 
120 FUELS 
 
 upon the fire. The best way to get an idea of the 
 composition of coal is to study what happens when 
 coal is distilled at a gas works for the purpose of 
 making coal gas. The coal is placed in a retort or 
 D-shaped vessel, made of clay, and kept red-hot 
 by a fire underneath. Various gases are given off, 
 and coke, consisting principally of carbon and 
 mineral ash, is left behind. A good deal of tar and 
 tarry oils condense on passing out of the retort, 
 as well as ammonia compounds ; while other sub- 
 stances, such as sulphur compounds and more am- 
 monia, are removed in the purifying processes, 
 leaving finally the coal gas, as we know it, to be 
 sent into the mains. 
 
 When the two principal products of this opera- 
 tion — that is to say, the gas and the coke — are 
 burned separately, they burn with practically no 
 smoke, and yet we have seen that when burned 
 together, by throwing the coal on a fire, they pro- 
 duce a good deal of smoke. It is obvious that it 
 cannot be the fault of the coke, and our experiment 
 with paraffin oil confirms the deduction that the 
 smoke is due to the imperfect combustion of the 
 other part of the coal. Consequently, if a laun- 
 derer wishes to avoid a smoky chimney, he must 
 do one of two things: he must either burn coke, 
 or anthracite (which is a sort of natural coke), or 
 he must so adjust his boiler fire and the draught 
 
FUELS 131 
 
 of air as to burn the gaseous part of his coal 
 completely. 
 
 With a mechanical stoker, which feeds finely 
 broken coal continuously and distributes it over 
 the fire, the difficulty is solved, because the coal 
 falls upon the fire in such small quantities at a 
 time that it does not cool it appreciably, and the 
 gases given off are readily burned ; but where, as 
 in a laundry boiler furnace, the coal has to be 
 placed on the fire in considerable quantities at a 
 time, the problem is a ditferent one. It is impos- 
 sible to prevent the smoke being produced, or, on 
 account partly of the local cooling of the fire and 
 partly of the large quantity of air which would 
 be required at that particular spot, to burn it 
 immediately. The important thing is to keep half 
 the fire bright, and then the carbonic acid pro- 
 duced by the hot fire will form carbon monoxide 
 with the carbon of the smoke, and this again will 
 be completely burnt further up the flue, so that 
 the resulting gases will be smokeless. 
 
 The Ash in Coke. 
 
 In considering the relative merits of coal and 
 coke, it must always be borne in mind that the 
 coke contains practically the whole of the ash in 
 the original coal. Eoughly, thirteen cwt. of coke 
 are obtained from one ton of coal, so that if a 
 particular coal contained 8 per cent, of ash, the 
 
183 FUELS 
 
 coke made from it at tlie gasworks would contain 
 roughly 12 per cent, of ash. Moreover, the greater 
 part of the sulphur will remain in the coke. 
 
 Valuing- Coal. 
 
 In purchasing coal, one of the first things to 
 take into consideration is the amount of ash it 
 contains. Not only is the ash useless in itself, but 
 the fuel has to heat up the ash as well as itself, 
 and all this heat is wasted; also, there is all the 
 trouble of removing the ash from the furnace. 
 It is important also to notice the character of the 
 ash, whether it is of a powdery nature, or whether 
 it is inclined to fuse together in the furnace and 
 cause a large amount of clinker, which will choke 
 the fire and give more work to the fireman. The 
 quantity of sulphur in the ash is also important, 
 as sulphur j)roducts deteriorate the metal of the 
 boiler flues. The most important thing of all, 
 however, is the calorific, or heat-giving value of 
 the coal. Every large launderer, on entering into 
 a coal contract, should secure a price on a guaran- 
 teed calorific value of so many thermal units. A 
 determination of calorific value will be made by a 
 good analyst for quite a small fee, and as coal, 
 even from the same mine, varies very much in 
 quality, it is important to have some check upon 
 the value of the fuel supplied. 
 
FUELS 123 
 
 Producer and Suction Gas. 
 
 As the gas known as ''producer" gas and ''suc- 
 tion" gas is coming so much into vogue, it would 
 be well to devote a few lines here to explaining 
 the principles upon which it is made. These two 
 gases are really the same from a chemical point 
 of view, so that I will treat them as one. If steam 
 be passed through red-hot fuel, it is broken up 
 with production of hydrogen and carbon mon- 
 oxide, thus : — 
 
 noil + (J = CO + II. 
 
 This gas is known as water gas, and is, by some 
 gas companies, mixed with the coal gas they sup- 
 ply to the public, the difference in illuminating 
 value being made up by the addition of a certain 
 amount of oil gas of high illuminating value. The 
 natural effect, however, of blowing steam into red- 
 hot fuel is to rapidly bring down its temperature, 
 so that, in making water gas the operation has to 
 be interrupted at the end of a few minutes to turn 
 on an air blast to get the fuel up to the proper 
 heat again. 
 
 In making "producer" or "suction gas," these 
 two operations — that is to say, the "run" and the 
 "blow" — are combined. When the fuel has once 
 been got up to the right heat, a mixture of steam 
 and air is passed through the fuel continuously. 
 The steam is broken up by the fuel into hydrogen 
 
134 FUELS 
 
 aud carbon monoxide, and the air, which, by the 
 way, is insufficient for complete combustion, in- 
 stead of burning' the fuel to carbonic acid, only 
 burns it to carbon monoxide, so that the whole 
 process results in the production of a mixture of 
 carbon monoxide and hydrogen. The heat-giving 
 properties of this gas are not nearly so great as 
 those of ordinary coal gas, so that it is necessary 
 to use a proportionately larger quantity of it in 
 the gas engine, or gas irons, or ironing machines, 
 in order to produce the same power or heat, as the 
 case may be. Except for the danger of the escape 
 of unburnt producer gas into the air, there is no 
 more danger in its use than in that of coal gas, 
 as, when once burnt, the gases are equally 
 harmless. Producer or suction gas is remarkably 
 economical, and I have very little doubt that be- 
 fore long it will bo used for driving aud heating in 
 many power laundries. 
 
CHAPTER XI 
 
 Fabrics 
 
 In the chapter on Starches, I have already men- 
 tioned starch cellulose, and I now come to a very 
 important class of substances, all of which are 
 modifications of the substance called cellulose. 
 This is very similar in chemical composition to 
 starch, and from it, or from different variations 
 of it, all vegetable fibres — linen, cotton, jute, bast, 
 hemp, etc. — as well as wood, are constructed. Cot- 
 ton wool, for example, is practically pure cellulose. 
 Although celhilose and its compounds, of which 
 more directly, do not give the resistance to com- 
 pression of steel, yet the tensile strength of a 
 linen fibre or a thread of such a substance as cellu- 
 lose tetra-acetate, is quite remarkable. 
 
 Cellulose is affected by strong acids and rapidly 
 by weak acids, and it is acted upon by alkalies 
 far more easily than is generally supposed. If 
 acid be used upon vegetable fibers for removing 
 stains or other purposes, care should be taken to 
 rinse very thoroughly, for it must always be re- 
 membered that, except in the case of a volatile 
 acid, such as acetic acid, the acid concentrates 
 
 125 
 
126 FABEICS 
 
 as water of dilution evaporates, and may leave 
 the acid in certain parts of the fabric in compara- 
 tively large proportion. This is equally true of 
 alkalies, and it must always be borne in mind that 
 any injurious action the alkali may have upon 
 the fabric may — and iDrobably will — be greatly 
 increased when a hot iron is passed over it, or 
 when, in the case of flat work, it is passed through 
 the calender. When comparatively strong alkali, 
 juch as 25 per cent caustic soda, acts upon a vege- 
 table fibre, it causes it to contract, at the same 
 time becoming much thicker with an increased 
 tensile strength. A cotton fibre treated in this 
 way is completely altered. Instead of presenting, 
 under the microscope, a flat, twisted, ribbon-like 
 appearance, it has, after treatment, a thick, 
 rounded aspect. This process is known as '*Mer- 
 cerization, ' ' from the name of the discoverer, John 
 Mercer. 
 
 Mercerized Cotton. 
 
 Mercerized cotton is now an important article 
 of commerce, and it is all made in this way, or 
 in some modification of it. There is hardly any 
 lustre in mercerized cotton if it is allowed to con- 
 tract to its full extent under the action of the 
 alkali, but if the cotton be stretched and thus pre- 
 vented from contracting when the alkali acts upon 
 it, the surface has a most beautiful lustre, which 
 
FABEICS 137 
 
 is used in many ways. Mercerized cotton has a 
 mnch higher affinity for dyes than ordinary cotton, 
 and this again is a valuable property. Bleached 
 cotton fibres will take a much higher degree of 
 lustre than when unbleached, so that the first 
 step in mercerization is to bleach the hanks of 
 cotton, which, by the way, are selected from the 
 Egyptian or Georgian long-stapled fibre in pre- 
 ference to the short-stapled American product. 
 After bleaching, the hanks are washed, stretched 
 on rollers, and passed through the mercerizing 
 solution. There are various modifications of this 
 process, some of which are distinctly injurious to 
 the fibre. The fibres may be injured in the bleach- 
 ing or may be over-stretched in mercerizing, or the 
 bleaching and mercerizing process is sometimes 
 combined to the injury of the fabric. Conse- 
 quently, in many cases, a fabric is produced by 
 mercerizing, which, instead of being stronger than 
 ordinary cotton, is materially weaker, as the 
 launderer knows to his cost. 
 
 The Action of Alkalies. 
 
 It would seem that, as such a strong alkali as 
 caustic soda has a strengthening process on the 
 fibres in the mercerization process, there can be 
 no harm in using plenty of alkali in the washing 
 machine; but the conditions are not similar. In 
 the first place, mercerization is carried on in the 
 
128 FABRICS 
 
 cold, or, if a higher temperature be employed, 
 care has to be taken to exclude air; while in the 
 washing process the fabric is boiled with a hot 
 solution of alkali, which is continuously aerated 
 by the rotation of the machine. Also, instead of 
 only happening once in the mercerizing process, 
 this boiling with hot alkali in the washing process 
 happens repeatedly. As a matter of practice, it is 
 found that wasliing with a large proportion of 
 alkali has a very injurious effect, causing the 
 fibres to swell and disintegrate, giving them at 
 the same time an unpleasant yellowish color, 
 which can only be whitened by bleaching. Of 
 all the fixed alkalies, caustic soda (or potash) has 
 the most, and borax the least, injurious action on 
 fibres. 
 
 Linen and Cotton. 
 
 Although essentially the same in chemical com- 
 position, the fibres of linen and cotton possess 
 very distinct physical characters. In the first 
 place, their origin is vevj different, linen being 
 derived from the long and very strong stem fibres 
 of the flax plant ; while cotton consists of the seed 
 hairs of the cotton plant, the fibres being com- 
 paratively short. They differ very much in 
 appearance under the miscroscope. The cotton 
 fibre presents the appearance of a flat twisted 
 ribbon thickened at the edges, and it is not easy to 
 
FABEICS 139 
 
 see the partitions between the cells which make up 
 the fibre. In the linen fibres the separate cells can 
 be easily distinguished, the fibre being thickened 
 where the two cells join. It is these thickenings 
 which make linen fibre easy to spin, as the fibres 
 readily attach themselves to one another ; in cotton 
 an artificial twist has to be given to join the fibres 
 together. On account of the much greater length 
 and strength of the linen fibre, it is much less 
 liable to "fluff" in the washing process than cot- 
 ton. On the other hand, cotton goes through the 
 calender [ironing machine] with much less dam- 
 age than linen. 
 
 Gun Cotton. 
 
 Cellulose readily forms compounds with nitric 
 acid, the best known one being gun cotton, which 
 is cellulose tri-nitrate. This is made by acting 
 upon cotton wool with a mixture of nitric and 
 sulphuric acids. The same substance mixed with 
 camphor forms celluloid, which accounts for its 
 dangerous inflammable character. Nitro-cellulose 
 also is used for some artificial silks. 
 
 Cellulose Acetates. 
 
 By acting upon cotton wool with a substance 
 known as acetyl chloride, a very beautiful com- 
 pound is produced, known as cellulose tetra- 
 acetate. This forms a most beautiful transparent 
 
130 FABBICS 
 
 colorless film, and the substance is used in the 
 production of an artificial silk. 
 
 Cellulose is readily dissolved by cuprammonium 
 solution (sulphate of copper to which ammonia 
 has been added to precipitate the hydrate, which 
 redissolves again in the excess of ammonia), and 
 advantage is taken of this in the manufacture of 
 Willesden paper — a thick waterproof paper used 
 for roofing and similar purposes. 
 
 Zinc chloride also rapidily dissolves cellulose. A 
 good method of separating cotton and wool is by 
 means of dilute sulphuric acid. The fabric is 
 dipped in the acid, and then dried and heated. 
 This concentrates the acid, which chars the cotton, 
 leaving the wool practically untouched. By shak- 
 ing and rubbing the cloth, the charred cotton can 
 be all removed, leaving the wool behind. 
 
 Wool. 
 
 "Wool is just as easily dissolved by caustic alkali 
 as cotton is by zinc chloride, and the wool can be 
 removed from a cotton-wool fabric with the great- 
 est ease, although it cannot be recovered. All 
 varieties of wool, hair, etc., used for textile 
 fabrics, although they may differ considerably in 
 mechanical structure, are very similar in com- 
 position. The peculiarity of wool is that the fibre 
 is made up of small sections fitted into one an- 
 other, and at each join, so to speak, there is a 
 
FABEICS 131 
 
 rough expanded serrated edge. These edges, when 
 the fibres are woven, lock into one another, and 
 every movement of the fabric caused by changes 
 of temperature, etc., causes these serrations to 
 interlock closer and closer, so that a woolen fabric 
 always has a tendency to shrink when washed. 
 Consequently, it is important that in the washing 
 process wool should be exposed to as few changes 
 of temperature as possible, and that the washing 
 process should be carried through quickly. High 
 temperature causes the fibres to move very much, 
 so that they ''felt" together with considerable 
 shrinkage. 
 
 Acids have comparatively slight action on the 
 fibre, although, as stated above, wool is rapidly 
 destroyed and dissolved by strong caustic alkalies. 
 Even weak alkalies have a most injurious effect on 
 the wool fibre, and all woolen goods should be 
 washed in a neutral soap solution at about 90 
 deg. Fahr. If it is necessary to use alkali, weak 
 borax — or, better, ammonia — is the best to employ, 
 although it must not be forgotten that ammonia 
 has a tendency to turn white woolen goods yel- 
 lowish. 
 
 Silk. 
 
 Silk, obtained from the cocoons of various kinds 
 of silkworm, is somewhat similar in composition 
 to wool, the most important substance present in 
 
133 FABEICS 
 
 silk being known as serecine. More will be said 
 about its properties in the chapter on "Dyes and 
 Dyeing." Silk in the laundry requires to be 
 treated very much the same as wool, and if similar 
 methods are employed, the silk will come to no 
 harm. If the launderer or cleaner and dyer 
 only had pure silks to deal with, he would be able 
 to accomplish his work without much difficulty, 
 but the terrible adulteration practiced in silk 
 weaving of late years has made his task an ex- 
 tremely difficult one. 
 
 It has been found that silk will take up very 
 large quantities of tin, barium, and other mineral 
 oxides without any apparent change in lustre or 
 appearance, and consequently a very considerable 
 proportion of the silk in the market is adulterated 
 to an enormous extent. By repeated treatment 
 with chloride of tin (stanic chloride), silk can be 
 loaded so that it contains only about 20 per cent 
 of genuine silk. 
 
 Although improvements in the methods of 
 weighting have rendered this weighted silk less 
 fragile than it used to be, it is rapidly acted upon 
 by light and by perspiration; a very small per- 
 centage of common salt, which is a normal con- 
 stituent of perspiration, rapidly disintegrating 
 weighted silk. Various unaccountable spots and 
 stains often occur in weighted silk. Consequently 
 weighted silk, although it may look quite sound, 
 
FABEICS 133 
 
 very often tears under the arm-pits or falls to 
 pieces when placed in water. When it is remem- 
 bered that mere exposure to light in the linen- 
 draper's window is quite sufficient to ruin the 
 fabric, it is needless to add that the launderer 
 must be on his guard against it. 
 
 Other Adulterations. 
 
 Cotton and linen goods are usually more or less 
 adulterated with filling and sizing materials, such 
 as glue, starch, gum tragasol, etc., on the one side, 
 and china clay on the mineral side. "Woolens, be- 
 sides being adulterated with cotton, are loaded 
 also, and when washing new blankets or new 
 woolen goods, care must be taken to get out the 
 dressing before proceeding to wash the article. 
 
 Chlorinated Wool. 
 
 There are a considerable number of woolen gar- 
 ments on the market, known as ''unshrinkable," 
 and these have in most cases been treated with 
 chlorine (or, rather, hypochlorous acid) which has 
 the effect of removing the serrations on the fibres 
 which cause them to interlock and shrink in the 
 ordinary way. 
 
CHAPTER XII 
 
 Dyes and Dyeing 
 
 Dyeing lies somewhat ouside the business of 
 the average launderer and is really quite a special 
 subject requiring a large amount of study and a 
 very considerable knowledge of chemistry — far 
 more than could be obtained from an elementary 
 manual — so that in this chapter I only propose to 
 touch upon the subject sufficiently to give the 
 reader what small insight is possible into the main 
 principles of dyeing. If he wishes to go farther, 
 he will find it necessary to study some larger work, 
 and at the same time to secure some practical in- 
 struction in the matter, to attempt dyeing with 
 only a book knowledge of the subject would be 
 disastrous. In the first place it may be stated that 
 dyeing is quite a different thing from mere stain- 
 ing of the fabric. If a piece of sugar be placed 
 resting in some colored fluid, the color will be 
 sucked up by capillary action until the sugar ap- 
 pears to have been regularly stained throughout. 
 In the same way a piece of cotton will take up a 
 stain if part of it is resting in a colored solution, 
 and if dried the stain will remain in it, but the 
 
 134 
 
DYES AND DYEING 135 
 
 colored appearance is purely temporary, and is as 
 readily removed as it is taken up. By dyeing, we 
 understand a much closer relationship between the 
 coloring matter and the fibre, than the instance 
 we have just discussed. Some coloring matters 
 can be dyed direct on to the fabric and remain 
 permanently fixed, and the reason for this will be 
 discussed subsequently; but in the majority of 
 instances the dyeing operation is by no means so 
 simple as this. 
 
 Theories About Dyeing. 
 
 There are various theories to account for the 
 dyeing action of colors on fabrics, but none of 
 these appear to cover the whole ground. In the 
 majority of cases the dyeing action appears to be 
 in the nature of a chemical relationship between 
 the fibre and the coloring matter ; while in others, 
 the coloring matter appears to be deposited in 
 the fibre in a purely mechanical manner. The 
 latter is undoubtedly the case with metallic pig- 
 ments, such as chrome yellow, and with indigo 
 dyed on the vat system, in which the reduced 
 indigo is deposited in the fabric and is afterwards 
 oxidized to develop the color. In any case the 
 structure of the fibre does not appear to be altered 
 in any way, and where the coloring matter can 
 be conveniently removed, the fibre, when examined 
 subsequently, appears to be entirely unaltered. 
 
136 DYES AND DYEING 
 
 Wool, silk, and animal substances generally be- 
 have in a very similar manner towards dyes, and 
 this is what might be expected from a knowledge 
 of their chemical nature. They are all very much 
 more readily dyed than cotton and other vegetable 
 fibres, which in the majority of cases require much 
 more drastic treatment to get them to take up the 
 dye. In fact it is usually necessary to introduce 
 an intermediary, if it may be termed so, in the 
 shape of a mordant, the nature of which will be 
 explained later. 
 
 Those who consider the action of dyeing to be 
 a mechanical one, compare the action of the fibre 
 on the dye to the solvent action of ether on an 
 aqueous solution of a dye. In most instances the 
 ether, if shaken up with the other solution, will 
 absorb all the color, and it is thought that the 
 action of the vegetable fibre at all events is sim- 
 ilar. On this supposition the differences observed 
 with different fibres are considered to be due to 
 variations in the pores of the fibre. Whatever 
 may be the exact case in regard to vegetable fibres, 
 it is pretty clear that in the dyeing of animal fibre 
 a genuine chemical combination takes place be- 
 tween some substance in the fibre and the coloring 
 material. 
 
 My readers will remember that a salt is pro- 
 duced by the union of an acid and an alkali or 
 base, and the same thing appears to take place in 
 
DYES AND DYEING 137 
 
 the dyeing of certain animal fibres. In some 
 cases the fibre appears to act as the base, and in 
 others as the acid, and it is very courions that 
 wool and silk can be dyed with plain, colorless 
 rosaniline, which is a substance bearing a chemi- 
 cal resemblance to ammonia, only much more com- 
 plicated. If the hydrochloride or combination of 
 rosaniline base with hydrochloric acid is used, the 
 whole of the hydrochloric acid will be found left in 
 the solution, indicating that the fibre takes its place 
 in the combination with the rosaniline. It is inter- 
 esting to note that in the case of wool, silk and 
 other animal matters, the dye appears to com- 
 pletely permeate the substance ; while in the case 
 of cotton, the dye lies more or less on the surface. 
 
 Classes of Dyes. 
 
 Dyeing substances may be divided roughly into 
 two classes, namely, those which act more or less 
 after the manner of pigments, that is to say, pos- 
 sess a strong coloring themselves, and only give 
 shades of the same color under all circumstances, 
 and those which are only lightly colored, or some- 
 times colorless in themselves, but produce strong 
 dyes in combination with a mordant or its equiva- 
 lent. Moreover, the coloring matters of the second 
 class vary very much in the shade they produce 
 according to the mordant with which they are 
 combined. As instances of the first class I may 
 
138 DYES AND DYEING 
 
 mention magenta, indigo, and azo-scarlet. These 
 are applied by steeping the fabric in hot solution 
 of the dye, to which has been added an acid, an 
 alkali, or a salt, such as Glauber's salt, as the case 
 may be. As instances of the second class, alizarine 
 (madder), cochineal and brazilein, yield different 
 colors according to the mordant with which they 
 are used. It is important to note in this connection 
 that magenta, while it will dye wool and silk di- 
 rectly, needs a mordant with cotton. 
 
 Another very important — one of the most im- 
 portant from the dyer's point of view — difference 
 between coloring matters, is the division into acid 
 and basic coloring matters. The two classes com- 
 bine with substances of the opposite chemical 
 character to yield a dye. For example, in the 
 case of alizarine red, which is an acid color, this 
 is dyed with alizarine — a base resembling ros- 
 aniline or ammonia already referred to, and alumi- 
 na — another base — as a mordant; while rosani- 
 line, being a basic color, requires hydrochloric acid 
 as a mordant. 
 
 Direct Dyes and Mordants. 
 
 A direct dye, such as magenta, will dye the 
 fabric without any assistance ; but there are many 
 dyes which require the aid of what is known as a 
 mordant. The substances most commonly em- 
 ployed for this purpose are metallic oxides, such 
 
DYES AND DYEING 139 
 
 as alumina, iron, hydrate of copper or chromium, 
 and so on, which are usually deposited first on the 
 fibre, and then, when the dyeing process proper 
 is carried out, the dye combines with the mordant, 
 or with the mordant and the fibre, and remains 
 permanently fixed. When the action is at an end, 
 the mordant — and in the case of wool and silk the 
 fibre itself — have combined with the coloring mat- 
 ter to form an insoluble substance, which is quite 
 fast to the action of water, but not to that of light. 
 
 As a good example of the action of a mordant, 
 it is an interesting experiment to mix an acid 
 color with sulphate of alumina and carbonate of 
 soda in solution ; the alumina will carry down the 
 whole of the coloring matter, leaving a clear color- 
 less solution. Mordants consisting of metallic 
 salts are of a basic character and are employed 
 with acid colors, and it is interesting to note how 
 very sensitive these basic metallic salts are. In 
 many cases it is only necessary to dilute a solution 
 of a metallic salt to obtain the basic salt, which 
 commences to precipate at once. 
 
 Wool is mordanted by boiling with dilute solu- 
 tions of metallic salts, but these are usually mixed 
 with organic acids such as formic acid, or acid 
 salts, such as cream of tartar, to assist in keeping 
 the mordant in solution. While the boiling pro- 
 ceeds, the metallic salt in contact with the fibre, 
 dissociates, forming a basic compound with the 
 
140 DYES AND DYEING 
 
 fibre. When the mordanting is complete, the fabric 
 is transferred to a vat containg the dye. The 
 composition of silk is very similar to that of wool, 
 and it is mordanted in a similar manner by boil- 
 ing with metallic salts, or by steeping for a cer- 
 tain number of hours in a more or less basic solu- 
 tion, and it is then dyed in the usual way. 
 
 Cotton and all vegetable fibers require quite 
 different treatment to wool and silk, as they con- 
 tain no active chemical substance such as that 
 existing in the first named. On account of the 
 absence of any active substance, cotton is not able 
 to break up and combine with any basic salt. The 
 most common mordants employed with cotton are 
 the metallic acetates. These decompose compara- 
 tively readily, leaving the basic salt deposited on 
 the cotton fibre. Acid mordants are very com- 
 monly used with cotton, the most common being 
 tannic acid. 
 
 Classes of Dyes. 
 
 Owing to the exceedingly complicated chemical 
 structure of most of the organic dyes now so 
 largely used, it would only be possible to go into 
 their composition after a large preliminary volume 
 on organic chemistry. Consequently, I can only 
 give a very rough indication of the classes of dyes 
 which exist. 
 
 First of all there are metallic dyes, such as 
 
DYES AND DYEING 141 
 
 chrome yellow, whicli are very much in the nature 
 of a pigment. 
 
 Next, there are the aniline dyes proper, of which 
 magenta is a well-known member. These bear 
 a distant resemblance to ammonia and its salts. 
 
 Then there are the important groups of which 
 alizarine is the best known. These, like the last, 
 are all derived from benzole (benzene), or coal 
 tar naphtha, or substances resembling benzene. 
 Unless combined with other substances they are 
 basic dyes. 
 
 Again, there is the nitro-group, of which picric 
 acid — the nitrate of phenol, or carbolic acid, as it 
 is commonly called — is a good example. These 
 are acid colors, and can be used for direct dyeing 
 without a mordant. 
 
 Further, there is the very important group of 
 sulphonic dyes, which are obtained by the action 
 of sulphuric acid on benzene and similar com- 
 pounds. The sulphuric acid is broken up, an atom 
 of oxygen and one of hydrogen being removed 
 by the action of benzine. These colors can be 
 dyed direct on to wool, silk, and cotton, and are, 
 perhaps, the most valuable dyes the garment dyer 
 possesses. 
 
 Direct Wool, Silk and Cotton Dyes. 
 
 In speaking of direct dyes, it must always be 
 remembered that dyes which are direct on wool 
 
142 DYES AND DYEING 
 
 and silk, are not necessarily so on cotton ; in fact, 
 although direct cotton dyes are not so scarce as 
 they used to be, there are not nearly so many 
 direct cotton dyes as direct wool dyes. The rea- 
 son for this is that the animal fibre takes a very 
 active part in the dyeing process ; while the vege- 
 table fibre is passive, and in many cases, so to 
 speak, takes up the dj^e under protest. These 
 important differences in the behavior of the 
 fibres in the presence of dyes makes it distinctly 
 difficult for the dyer to deal with mixed fabrics of 
 wool and cotton, although there is now a fairly 
 numerous list of dyes which will dye both wool 
 and cotton direct in the same bath. With such 
 dyes, temi3erature plays a most important part. 
 The dye will usually go on to the wool when it 
 is hot and the cotton when it is cold, and it will 
 even leave the cotton to go on to the wool when 
 hot so that much care and judgment is required. 
 
 Natural Dyes. 
 
 Although naturally occuring dyes, such as in- 
 digo, logwood, fustic, catechu, etc., are still of con- 
 siderable importance to the piece dyer, they are 
 little used in garment dyeing. They possess the 
 advantage of being very fast to light and the 
 washing process, and probably a large quantity of 
 fabrics dyed with them pass through the wash- 
 room every week. 
 
DYES AND DYEING 143 
 
 Laundry Blues. 
 
 A few words on blues used in the laundry may 
 very well come in here. The blue used originally 
 was indigo, or rather a soluble compound with 
 sulphuric acid, but, except perhaps in domestic 
 washing, indigo is now very little employed for 
 laundry purposes. Prussian blue is ued to some 
 extent. This is a ferrocyanide of iron, is rather 
 apt to have a greenish cast, and is credited with 
 leaving an iron stain in the goods when they are 
 re-washed. Ultramarine is employed a good deal. 
 This coloring matter is formed by roasting to- 
 gether a mixture of china clay, charcoal and sul- 
 phate or carbonate of soda. Its composition and 
 color vary considerably from a greenish to a dark 
 blue shade, and, as is always the case with pig- 
 ments, the depth of color and value depends as 
 much or more upon the fineness of the grinding, 
 as upon the original color. Ultramarine is quite 
 insoluble in water, and although it appears to 
 dissolve, it is really only in a state of suspension. 
 It is really somewhat of the nature of powdered 
 glass, and is quite unaffected by weak acids and 
 alkalies. Other blues which are largely employed, 
 shade, from violet blue to greenish blue. These 
 fiare aniline blues, which can be obtained in any 
 are true dyes, soluble in water, and must be used 
 with care, because the fabric is actually dyed, and 
 if excess of blue be employed, it cannot be re- 
 
144 DYES AND DYEING 
 
 moved except by some reducing agent, such as 
 hydraldite or titanous chloride (stripping salts). 
 It is very important in selecting a blue, to use one 
 with a slight violet shade ; on no account should a 
 greenish blue be employed, as the object of the 
 blue is to cover up the natural yellowish color 
 of the cotton or linen fibre. 
 
CHAPTER XIII 
 
 Water 
 
 As water is the most important article, the 
 finest washing compound, so to speak, that the 
 launderer uses, it certainly deserves a chapter to 
 itself. I have already dealt with its chemical 
 structure, and what I specially propose to deal 
 with in this chapter is the composition, purifica- 
 tion and general properties of the natural waters 
 which the launderer has to use in practice. 
 
 In the first place the action of water is far more 
 than a purely mechanical one. Water wets things 
 and other liquids do not. Benzine, for example, 
 although it may saturate a fabric, does not ''wet" 
 it. It has been found that most chemical reactions, 
 in which apparently water is in no way concerned, 
 will not proceed in the absence of water ; so that 
 water must possess some action peculiar to itself 
 which is not yet thoroughly understood. 
 
 The Universal Solvent. 
 
 Water probably approaches closer to the uni- 
 versal solvent that the ancients dreamed of, than 
 
 145 
 
146 WATER 
 
 most people suppose. There are very few things 
 which will not dissolve to some extent in water, 
 and distilled or rain water, which is free from any- 
 dissolved mineral matter, possesses remarkable 
 solvent powers. If placed in a glass or earthen- 
 ware vessel, it rapidly attacks the glass or the 
 glaze of the earthenware, dissolving out the alkali. 
 If placed in metal vessels or pipes, the metal, if it 
 be iron, lead or zinc, is quickly attacked by the 
 water with probably the help of the dissolved air 
 which it contains. This powerful solvent action of 
 what is commonly called ''soft" water, is alone 
 a good reason for the launderer to use it as much 
 as possible. 
 
 Another effect of this powerful solvent tendency 
 of soft water is that as it passes through the soil, 
 carrying, in addition to its own solvent powers, 
 some carbonic acid from the air and some of the 
 humic acid from the decomposing vegetable matter 
 in the soil, both of which help it to attack the 
 rocks, it dissolves out a large variety of mineral 
 substances. The most common are sodium chloride 
 (common salt), magnesium chloride and calcium 
 chloride, calcium sulphate (gj^psum), magnesium 
 sulphate and calcium carbonate (chalk and lime- 
 stone). In addition, some waters contain peaty 
 matter derived from bog moss on the hills, and 
 iron, of which more later. 
 
WATER 147 
 
 Lime in Water. 
 
 All or any of the substances just mentioned are 
 undesirable in the washing machine, as, with the 
 exception of the peaty matter, they combine with 
 the fatty acid of the soap, rendering it useless 
 from the launderer's point of view, and thereby 
 causing a large waste, as well as the bad color, 
 streaks and other blemishes due to the lime soap 
 already referred to. Another objection to the pre- 
 sence of lime in the water used in the washing 
 machine is that, although most of it goes into com- 
 bination with the soap or is thrown out in a loose 
 form by the soda, yet an appreciable amount very 
 frequently is deposited in a crystalline form in 
 the fibres of the linen, where it accumulates with 
 every wash until the amount present is quite 
 appreciable. These sharp crystals of carbonate 
 of lime rapidly assist the ordinary process of wear 
 and tear, and the life of the article becomes 
 exceedingly short. 
 
 Hardness. 
 
 Chloride of calcium and magnesium, and sul- 
 phate of calcium (gypsum), and magnesium are 
 soluble in water in the ordinary way, and if the 
 water be boiled, the only effect is to concentrate 
 them until you get them so concentrated that they 
 begin to crystallize out. These salts constitute 
 what is known as the "permanent hardness" of 
 
148 WATER 
 
 water. The carbonate of calcium is kept in solu- 
 tion only by virtue of the carbonate acid present 
 in the water; it is really a bicarbonate (see page 
 33), and if the extra carbonic acid can be removed, 
 the carbonate of calcium will fall to the bottom. 
 Boiling the water has the effect of removing this 
 carbonic acid, so that the hardness produced by 
 carbonate of calcium or carbonate of lime, as it is 
 often called, is known as "temporary." Instead 
 of boiling the water we can remove the carbonic 
 acid by adding either solution of lime, or milk of 
 lime, or caustic soda. Thus: — 
 
 Calcium bicarbonate. Slaked lime 
 CaCOa H,0 CO. + CaO H,0 
 
 Calcium Carbonate. Water 
 = 2 CaCOa + 2 H,0 ; 
 or — 
 
 Caustic Soda. 
 CaCOs H,0 CO. + 2 NaOH 
 
 Carbonate of Soda. 
 = CaCOa + Na.COs + 2 H^O. 
 
 Similarly, the permanent hardness can be re- 
 moved by treatment with carbonate of soda, thus — 
 
 Calcium Carbonate Sulphate 
 
 sulphate. of soda. of soda. 
 
 CaSO, + Na.COa = CaCOa + Na.SO,. 
 
WATEE 149 
 
 In softening water for laundry or other industrial 
 uses, a combination of these two processes is 
 employed, so that all, or nearly all, the temporary 
 and permanent hardness is removed. On account 
 of the powerful solvent action of perfectly soft 
 water, to which I have already referred, it is not 
 advisable to make the water perfectly soft, as it 
 would then be unsuitable for use in the boiler. 
 
 The hardness of water is usually stated in 
 analytical reports as parts per 100,000 or grains 
 per gallon, that is to say, per 70,000 and one degree 
 of hardness corresponds to one grain of carbonate 
 of calcium per gallon. Consequently, a water 
 certified to contain 5 degrees of permanent hard- 
 ness and 16 degrees of temporary hardness would 
 contain 16 grains per gallon of carbonate of lime 
 as temporary hardness and the equivalent of 5 
 grains of carbonate of lime as permanent hard- 
 ness. Hardness is estimated by means of what 
 is known as Clark's Soap Test, full particulars of 
 which will be given in the last chapter. A definite 
 quanity of water is taken, and a standard solution 
 of soap is added, a little at a time, until a per- 
 manent lather is obtained on shaking the liquid. 
 
 Iron can usually be removed from natural water 
 by aerating it. If water containing iron be 
 thoroughly aerated, and allowed to stand, the iron 
 will usually fall to the bottom; or it can be re- 
 
150 WATER 
 
 moved more quickly by passing it through one 
 of the usual filters employed in water softening. 
 The materials used in the ordinary water soften- 
 ing process will remove the iron at the same time 
 as the lime. 
 
CHAPTER XIV 
 
 The Chemistey of the Washroom 
 
 All of the subsequent processes of starching, 
 ironing, and so forth, depend for their success 
 upon the article being properly washed in the first 
 instance, so that the proper conduct of the wash- 
 room is of vital importance to the whole establish- 
 ment. The theory of the washroom has already 
 been dealth with more or less, but there will be 
 no harm whatever in recapitulating. 
 
 There are three kinds of ''dirt" the launderer 
 has to contend with, namely, albuminous animal 
 dirt, caused by exudations from the skin, particles 
 of epidermis and animal stains generally; next 
 there is greasy matter, which, together with the 
 first, helps to keep the mineral dirt or general dust 
 stuck to the fabric ; lastly, in starched garments, 
 there is old starch. 
 
 Each of these kinds of dirt requires different 
 treatment for its removal. In the first place albu- 
 minous matter is readily coagulated by heat and 
 rendered permanently insoluble; consequently it 
 is necessary to remove this before the temperature 
 is allowed to rise to any extent, the best plan being 
 
 151 
 
153 CHEMISTRY OF THE WASHROOM 
 
 to soak the linen for as long as conveniently pos- 
 sible in plain water containing a little alkali, which 
 helps to render the albuminous matter soluble. 
 The next step with this albuminous matter is to 
 wash the articles with soap and soda, in warm 
 water only, which removes a good deal of the 
 loose dirt and most of the albuminous matter; 
 finally the articles are boiled with soap and soda, 
 and here I must emphasize the necessity of 
 having a good lather in the machine. 
 
 If there is no lather in the machine it shows 
 that the quantity of soap is insufficient ; that some 
 substance present, be it lime or manufacturer's 
 dressing, or whatever it may be, has taken up the 
 fatty acid of the soap and that more is required. 
 So long as there is no lather there is no free soap 
 present. Where this happens as a matter of 
 practice you are quite as likely to boil the dirt into 
 the clothes as to boil it out, and working in this 
 manner is a frequent source of bad color. More- 
 over, in the case of a hard water, the deposition 
 of lime soap in the goods is certain to be greatly 
 increased where they are washed without sufficient 
 soap. 
 
 The action of the soap and alkali in the first 
 wash — I am dealing here with body linen — and 
 the boil, is to emulsify the grease and the loose 
 dirt, having nothing now to hold it on to the fabric, 
 comes away. In addition to removing the dirt, 
 
CHEMISTEY OF THE WASHROOM 153 
 
 boiling, possibly due to the action of the steam 
 causing the production of ozone — the active form 
 of oxygen — or in some way connected with the 
 aeration of the goods in the revolving machine at 
 that temperature, has a great effect in whitening 
 and sweetening the goods. Moreover, it must be 
 remembered, that exposure to boiling temperature 
 for any length of time causes the destruction of 
 all disease germs. 
 
 Rubbers. 
 
 Rubbers, on account of the very miscellaneous 
 nature of the dirt which they contain, require 
 somewhat similar treatment to body linen, al- 
 though the preliminary breakdown can be omitted. 
 Nevertheless, it is a good plan to run them in plain 
 water for a few minutes to wet them thoroughly, 
 and to remove any loose dirt before commencing 
 to wash. 
 
 Sheets and Table Linen. 
 
 Sheets, as a general rule, require very little 
 washing compared to other goods, and are easy to 
 deal with, and there should be no great difficulty 
 in washing table linen, for, apart from fruit and 
 wine stains, and occasional iron mould, the prin- 
 cipal dirt is grease, which comes out readily 
 enough. As a rule, launderers keep these articles 
 much too long in the machine, probably because 
 
164 CHEMISTRY OF THE WASHROOM 
 
 SO many insist upon using too mu^h alkali and not 
 enough soap. This tendency is at the bottom of 
 half the launderer's troubles. 
 
 Shirts and Collars. 
 
 The washing of shirts and collars raises the 
 question of old starch. If this be not removed, it 
 is fatal to any satisfactory results afterwards. 
 Here again there is not much object in an extended 
 breakdown. The first wash with soap and soda 
 in warm water only, not hotter than the hand can 
 bear, should loosen the animal matter; while a 
 thorough good boil should get rid of the starch. 
 In regard to the wear and tear of shirts and col- 
 lars, however, it is well worth while considering 
 whether malt extract might not be used to advan- 
 tage to free shirts and collars from old starch by 
 simple fermentation, thus securing freedom from 
 old starch with very little washing. In the case of 
 colored starched articles, malt extract is simply 
 invaluable. 
 
 Washing Materials. 
 
 Before considering silks and flannels, it would 
 be well to deal briefly with washing materials. Of 
 the hard soaps there are curd, mottled, yellow or 
 pale, and oil soaps. Of the soft soap there are 
 various makes, all more or less similar in char- 
 acter. For general washroom use, the inex- 
 
CHEiMISTRY OF THE WASHROOM 155 
 
 perienced laimderer is certainly safest with a 
 good curd mottled soap. It cannot be adulterated, 
 and he is certain of good results in the washing 
 machine. It has the disadvantage, however that 
 goods washed with it require more thorough rins- 
 ing than with any other soap. Also it is alkaline, 
 and must not be used on colored goods. The 
 yellow soap is said to give in time, a brownish 
 tinge to linen washed with it; but I have not 
 noticed it, and excellent results certainly can be 
 obtained with it. Like curd soap, it is made 
 largely from animal fats, and requires thorough 
 rinsing. It is, or should be, neutral. Oil soap is 
 made from olive, sesame or other oils, and very 
 often from the waste oils of the candle factory. 
 It is an excellent soap — neutral, and easily rinsed 
 out of the goods. For that reason it is very suit- 
 able for colored goods or other articles which are 
 not boiled, and which cannot be rinsed with hot 
 water. Some oil soaps, however, leave a peculiar 
 smell in the goods, and this must be guarded 
 against. The odor of all the soaps used in the 
 washroom must be carefully watched. Soft soaps 
 are excellent for flannels and blankets. 
 
 Alkalies. 
 
 Alkalies in use in the washroom are washing 
 soda or soda crystals, 58 per cent alkali, and 
 yarious proprietary compounds, some good and 
 
156 CHEMISTEY OF THE WASHROOM 
 
 some bad, including in this category those which 
 contain sodium silicate. 58 per cent alkali is 
 practically pure carbonate of soda ; while washing 
 soda or soda crystals (see page 34) contain a 
 large proportion of water. The equivalent quanti- 
 ties to use, if you are changing from one alkali to 
 another, will be found on page 179. Alkali in 
 any form should never be put into the machine 
 in the solid state, but always dissolved in water. 
 For general use it is a good plan to add the alkali 
 to the soap solution; or, rather, the other way 
 round, dissolving the alkali first and then the 
 soap, instead of putting them in the machine " 
 separately. The reason for this is that a neutral 
 soap is very much inclined to dissociate to some 
 extent when dissolved, and the free fat is prob- 
 ably the cause of many unexplained troubles. 
 
 Soap Solution. 
 
 Soap chips containing something over 70 per 
 cent of fatty acids are largely used in America, 
 and it is necessary to use some form of alkali in 
 order to dissolve the whole of the fatty acid, which 
 would otherwise separate out. Instead of having 
 two tanks in the wash room, one for soap and the 
 other for alkali, as is often done, I prefer to use 
 only one tank. Add the alkali first, turn on 
 steam, and then add the soap. This prevents any 
 
CHEMISTEY OF THE WASHEOOM 157 
 
 separation of insoluble fatty acid which would be 
 almost sure to occur if the alkali were added after 
 the soap. By working in this manner, the quan- 
 tity of alkali can be reduced. Caustic soda should 
 not be used in the laundry at all, except in the 
 water softener. It has a most injurious action on 
 fibres, and is quite unnecessary. Ordinary alkali 
 or sodium carbonate is quite strong enough, and 
 most launderers use a great deal too much of that. 
 The theoretical quantity of alkali required for 
 soft, or even for hard water, is very small com- 
 pared with that generally in use. This is prob- 
 ably too little for practical purposes, but I should 
 regard 4 ozs. of actual sodium carbonate as a 
 maximum for a 100-shirt machine. No pains 
 should be spared to keep down the excessive use 
 of alkali in the washroom, as it causes rapid wear 
 in the linen and a yellow color to boot. 
 
 Rinsing. 
 
 A few words now about rinsing. Where soft- 
 ened water is in use, as it should be everywhere 
 for washing, the rinse which follows the last wash 
 should be with hot soft water ; then should follow 
 a second rinse with hot soft and cold hard water 
 mixed, and a last rinse with cold hard water. 
 Where soft water alone is used it is difficult to get 
 rid of the last traces of soap, and there is a ten- 
 
158 CHEMISTRY OF THE WASHROOM 
 
 dency for the goods to feel sticky, but the least 
 trace of lime in the water gets over this difficulty. 
 Where soft water is not to be had, and washing 
 with hard water is unavoidable, it is an excellent 
 plan to add acetic acid — in the proportion of, say, 
 half a pint of commercial acid to a 100-shirt ma- 
 chine — to the second rinse. This decomposes any 
 lime soap or lime salts there may be in the goods, 
 so that they are washed out, and the goods keep 
 a good color and wear better. 
 
 Bleaching". 
 
 Indiscriminate bleaching or insufficient care in 
 the use of bleaching materials is the cause of any 
 amount of trouble. A very large number of the 
 articles which are sent to me in holes, for opinion 
 on the cause of the trouble, are due to the use of 
 chlorine bleaches, and the rest, to the use of ex- 
 cess of alkali. "While it may be necessary to use a 
 chlorine bleach to remove stains from table linen, 
 this should be done with all jDossible care, and 
 only the actual stained portions bleached, unless 
 they are too numerous or too extensive, when the 
 whole cloth must be treated. Collars should be 
 bleached at very rare intervals, if at all, and 
 there should be nothing else which requires this 
 treatment, except in the case of actual stains. On 
 account of the danger of allowing any form of 
 
CHEMISTRY OF THE WASHROOM 159 
 
 chlorine bleach in the hands of the average wash- 
 man, some launderers prefer to let the stains in 
 table linen go unremoved, or to treat them only 
 at the special request of the owner. 
 
 There are many reliable made up chlorine 
 bleaches on the market, but where the launderer 
 thinks it best to make his own, a good method is 
 to take 5 lbs. of bleacliing powder (chloride of 
 lime), dissolve in a bucket with water, and add 
 5 lbs. of carbonate of soda (58 per cent, alkali), 
 or its equivalent in soda crystals. Allow it to 
 stand all night to settle, and then strain through 
 muslin into a 5 gallon jar of water. Use one pint 
 of this to 15 gallons of water. (Note. — The 
 strength of this is approximately 0.03 per cent, 
 available chlorine.) 
 
 Souringf. 
 
 After bleaching, the goods should have a bath 
 in dilute acetic acid of a strength of one pint of 
 the commercial acid in 40 gallons of water. The 
 effect of this is to decompose the sodium hypo- 
 chlorite with production of hypochlorous acid — a 
 very powerful bleaching agent, and easily remov- 
 able. On account of its greater convenience, 
 oxalic acid is usually employed in America, but 
 acetic is greatly to be preferred on account of the 
 absence of injury to the goods. 
 
160 CHEMISTRY OF THE WASHROOM 
 
 Iron Mould. 
 
 An indispensable reagent in the washroom is 
 oxalic acid for the removal of iron mould. A con- 
 venient strength is about 10 per cent. It should 
 be used warm, and steeping for a few minutes 
 usually suffices to remove the stain. The article 
 should be well rinsed afterwards, as the acid has 
 an injurious action on the fibre. It is not gener- 
 ally known that warm oxalic acid will remove 
 mildew stains. 
 
 Silks and Flannels. 
 
 I must now deal, in a few words, with the 
 washing of silks and flannels. There are two 
 essential things to be observed here, namely, that 
 the temperature of washing should not exceed 90° 
 Fahrenheit, and that the wash water should be 
 neutral. A good soft soap is the best for washing 
 silks and flannels, and the only alkalies that 
 should be used are ammonia or weak borax. The 
 latter is, perhaps, the better of the two, as am- 
 monia is inclined to turn white silks or flannels 
 yellow. The use of alkalies, such as carbonate of 
 soda or potash, upon flannels or silks, is most 
 dangerous, and many articles have been submitted 
 to me which have been ruined in this way. In 
 connection with this it must always be remem- 
 bered that curd soap is alkaline, and consequently 
 it should not be used for flannels. 
 
CHEMISTRY OF THE WASHROOM IQl 
 
 It is most important that the temperature, in 
 washing flannels, should be kept as constant as 
 possible, that is to say, all the wash waters and 
 rinse waters should be at a temperature of 90° 
 Fahr. ; while the drying-room for flannels, if they 
 are dried indoors, should be about 100° Fahr. By 
 keeping the temperature constant, the shrinkage 
 of flannels, due to the serrations of the fibres 
 interlocking or felting as the fibres move under 
 the change of temperature, is prevented. It is 
 also very important that as much water as pos- 
 sible should be wrung out of the garment before 
 hanging out to dry, as the evaporation of this 
 water, especially if hung in a cold wind in the 
 open air, is very liable to cause shrinking, for the 
 reason just mentioned. 
 
 Colored Goods. 
 
 Colored cotton or linen goods are best washed 
 with a neutral oil soap in lukewarm water. If a 
 color shows a tendency to ''bleed," a bath in 
 acetic acid will usually stop it, besides helping to 
 brighten the color. 
 
CHAPTEE XV 
 
 Some Simple Analytical Wobk 
 
 In analyzing a substance, that is to say, divid- 
 ing it up into its component parts, there are two 
 things to be done: first, to find out what are the 
 components ; secondly, how much of each of them 
 is present. In some cases it is sufficient to know 
 what substances are present in the material you 
 are dealing with; while it is not important to 
 know exactly how much of each of them is there ; 
 as, for example, if an article is yellow in color, 
 you are satisfied with knowing that it is due to 
 the presence of iron, and it would not be of any 
 particular advantage to know how much iron. In 
 other cases you can determine not only whether 
 a particular substance is present, but also exactly 
 how much is there at the same time. 
 
 For simply finding out what substances are 
 present you will not require apparatus for accu- 
 rate measurement, but for determining quantities, 
 accurate weighing and measuring of everything 
 used is essential. I will refer to the different 
 apparatus, which will only be what is absolutely 
 required, as I pass along, and will give a sum- 
 
 163 
 
SIMPLE ANALYTICAL WOBK 163 
 
 mary at the end of the chapter for the guidance 
 of those who wish to purchase an outfit for doing 
 a little simple analytical work. 
 
 In the first place you will find it necessary to 
 get a few glass stirring rods, a few glass or porce- 
 lain vessels in which to conduct your operations, 
 and a few bottles in which to contain your chem- 
 icals. SupjDosing these have been obtained, with 
 the necessary chemicals (see list on page 176), I 
 will get to work. 
 
 Tests for Alkalies. 
 
 1. If in solution take up a drop on a clean 
 stirring-rod and put the drop on a piece of red 
 litmus paper. It will be turned blue if an alkali 
 is present. 
 
 2. Add one or two drops of solution of phenol- 
 phthalein to the solution. It will turn red in the 
 presence of alkali. 
 
 3. Add one or two drops of solution of methyl- 
 orange to the solution. If alkaline it will turn 
 yellow. 
 
 4. Alkalies in Fabrics. — Boil a piece of the fab- 
 ric, if cotton or linen, in clean distilled water in a 
 clean dish for two or three minutes, and add one 
 or two drops of phenol-phthalein. If alkaline it 
 will turn red. 
 
 Note. — In connection with this it must always 
 be remembered that soap insufficiently rinsed out 
 
164 SIMPLE ANALYTICAL WORK 
 
 may appear as alkali in this test. If the fabric 
 be wool or silk the water used for dissolving out 
 the supposed alkali must only be warm. 
 
 5. Alkali in Soap. — In order to test whether a 
 soap contains free alkali, the easiest way is to 
 make a shallow hole in the soap about as large as 
 a sixpence, and allow two or three drops of phenol- 
 phthalein to fall into it. If the soap is alkaline a 
 pink color will be produced. 
 
 Test for Acid. 
 
 6. If a solution is being tested, take a drop on 
 a clean stirring-rod, and place it upon a piece of 
 blue litmus paper. If acid be present it will turn 
 red. 
 
 7. Add one or two drops of solution methyl- 
 orange to the solution. If acid it will turn red. 
 Phenol-phthalein under like conditions would be 
 colorless. 
 
 When a fabric is being tested it can be treated 
 in exactly the same way as for alkalies. 
 
 Test for Presence of Chlorine Bleach. 
 
 8. Immerse a portion of the fabric in warm 
 water for five minutes, squeeze the excess out of 
 the fabric so that it mixes with the rest and add 
 some solution, or, better, two or three crystals of 
 potassium iodide. If chlorine be present the solu- 
 
SIMPLE ANALYTICAL WORK 165 
 
 tion will turn yellowish. The adition of a few 
 drops of starch solution will turn it from yellow 
 to deep blue. 
 
 Test for Iron. 
 
 9. If a fabric is being tested, moisten the 
 stained portion with 10 per cent, hydrochloric 
 acid and add a drop of potassium ferrocyanide 
 solution. If iron be present it will turn blue. The 
 color will easily come out with ordinary carbonate 
 of soda solution. 
 
 10. If a water is being tested, the best way is 
 to concentrate it by boiling down, say, a pint, 
 nearly to dryness, in a white porcelain dish. Then 
 add hydrochloric acid and one or two drops of 
 potassium ferrocyanide. 
 
 Test for Copper. 
 
 11. Copper sometimes causes a stain on a 
 fabric. Moisten the stain with hydrochloric acid 
 and add a drop or two of potassium ferrocyanide. 
 If copper is present it will turn red. 
 
 Test for Old Starch. 
 
 12. Moisten the collar, or whatever it may be, 
 with warm water and add one or two drops of 
 solution of iodine in potassium iodide. If there is 
 
166 SIMPLE ANALYTICAL WOEK 
 
 any starch present an intense blue color will be 
 produced. As this test is very delicate the color 
 will be produced by a very minute quantity of 
 starch. The test solution is made by dissolving, 
 say, 10 grams or i/^ oz. of potassium iodide in 100 
 c. c, or 4 ozs. of distilled water, and adding a few 
 crystals of idodine. 
 
 Test for Lime Soap. 
 
 13. Dark stains and bad color are often pro- 
 duced by lime soap in the fabric. Soak part of 
 the stained portion for a few minutes in a dish 
 containing 10 per cent hydrochloric acid and then 
 see if the stain is removed. Also see if there are 
 any globules of fat from the soap decomposed by 
 the acid floating in the solution. 
 
 The Fastness of Dyes. 
 
 14. In testing the fastness of dyes on a fabric 
 the best way is to cut a small portion from a hem 
 or some turned in part of the garment, place it in 
 a small porcelain dish and try (a) the effect of 
 neutral soap and water in the cold; (&) when 
 warmed to whatever temperature it is proposed 
 to wash at; (c) the effect of water rendered alka- 
 line with one or two drops of 10 per cent caustic 
 soda. 
 
SIMPLE ANALYTICAL WOEK 167 
 
 The Valuation of Soap. 
 
 15. Altliough the complete analysis of a soap is 
 a complicated matter requiring extensive know- 
 ledge of chemistry and considerable analytical 
 experience, it is a comparatively easy matter to 
 arrive at a rough estimate of the value of any 
 particular soap in a few moments. As I have 
 explained above the value of soap can, for all 
 practical purposes, be gauged by the amount of 
 fatty acid which it contains, and it is quite a 
 usual thing to see a soap quoted as containing so 
 much per cent of fatty acid. The easiest way to 
 form a rough estimate of this amount is to have 
 two tall glass jars of exactly the same pattern, 
 and to make up a standard solution of any well- 
 known and thoroughly reliable soap, dissolving, 
 say, four ounces of this soap in water and making 
 it up to exactly a quart. 
 
 When it is desired to test the value of a new 
 consignment or new sample of soap, half an ounce 
 should be carefully weighed out from the middle 
 of the bar, and dissolved in water and placed 
 in one of the tall jars. At the same time 5 fluid 
 ounces (i/4 pint) of the standard solution should 
 be placed in the other jar, and sufficient dilute 
 sulphuric acid added to each jar to decompose the 
 soap and throw down the fatty acid, which will 
 immediately appear as a thick, white, flocculent 
 
168 SIMPLE ANALYTICAL WOEK 
 
 [wooly] precipitate. When this has been done, 
 plain water must be added, to each jar until the 
 liquid in both jars is exactly the same height. 
 After standing for, say, ten minutes for the precip- 
 itate to settle, a glance will show how the amount 
 of fatty acid in the two soaps compares. If a 
 soap contains its proper proportion of fatty acid 
 it is not likely to have much the matter with it in 
 other respects. 
 
 A More Complete Analysis of Soap. 
 
 For the benefit of those who wish to go more 
 thoroughly into the matter and make a complete 
 analysis, I will explain as simply as possible how 
 this can be accomplished satisfactorily with the 
 appliances the launderer is likely to have ready 
 to hand. The first thing that will be required is 
 a pair of scales, such as the amateur photographer 
 uses, and also the equally necessary weights. If 
 a launderer does propose to do work of this kind 
 it will be well worth his while to purchase a set of 
 weights on the metric system, which can be ob- 
 tained for a few pence, as the calculation of the re- 
 sults is so much simplified ; nevertheless, the work 
 can be done equally well using grain weights in- 
 stead of grams, if the launderer does not possess 
 the latter. I shall give the figures that follow on 
 the metric system, but in case the reader wishes to 
 
SIMPLE ANALYTICAL WOEK 169 
 
 use grains he must remember that roughly speak- 
 ing 15 grains go to the gram, and instead of weigh- 
 ing out 5 grams of soap, as I am about to suggest, 
 he will find it convenient to weigh out 100 grains. 
 
 Sampling Soap. 
 
 Before going any farther, I must say a few 
 words about sampling soap. If the latter be sup- 
 plied in the form of powder or shreds, as is some- 
 times done, the sampling is easy enough, all that 
 is required being to take the sample some little 
 distance away from the outside of the package; 
 but in the case of bar soap, the sampling is not 
 quite so easy. Soap, even the best laundry soap, 
 contains an appreciable amount of water, varying 
 from about 25 per cent in the case of the best 
 soaps, to a very much larger amount in the case 
 of inferior soaps. Directly this soap is exposed 
 to the air, it commences to lose moisture, and the 
 rate of shrinkage in a bar of soap, on keeping, is 
 one excellent test of the value of the soap. A 
 really good soap will not lose its shape appreci- 
 ably, but while shrinking a little will get much 
 harder and darker in color on the outside; while 
 a poor watery soap will shrink in the most notice- 
 able way, the bar frequently curling up and losing- 
 its shape altogether. In consequence of this loss 
 of water on exposure to the air, it is very import- 
 ant, when taking a sample from a bar of soap, to 
 
170 SIMPLE ANALYTICAL WORK 
 
 cut it in half and take the sample as fairly as 
 possible from the middle. 
 
 The Analysis. 
 
 In making the extended analysis, weigh ont 
 first of all about 5 grams in a porcelain dish; it 
 is too tedious a process to get an exact 5 grams, 
 so you get somewhere about that amount, making 
 an accurate record of the weight taken. Suppose 
 in this instance the weight was 5.4 grams. After 
 weighing, place the dish containing the soap in a 
 double saucepan or porridge pot, and keep it 
 boiling until the soap (and dish) are found not to 
 lose any more weight. Let us suppose that the 
 fresh weight is 4.1 grams. This means that the 
 soap, in drying, has lost 1.3 grams of water, and 
 the soap is now dry. A piece of filter paper or 
 blotting paper is now placed in a glass funnel 
 and the dry soap carefully brushed into it with a 
 camel hair brush, taking care that none is lost. 
 Alcohol (rectified methylated spirit) is poured 
 slowly over the soap until all is dissolved, and the 
 filter is quite clear of soap, the alchol with the 
 dissolved soap being received in a glass vessel 
 underneath. This now contains an alcoholic solu- 
 tion of soap, any mineral matter, such as carbon- 
 ate of soda or silica, being left in the filter. If it 
 is desired to estimate this, the filter can be placed 
 in a dish, burnt to an ash and weighed; but mth 
 
SIMPLE ANALYTICAL WOEK lyj 
 
 most modern soaps the impurities of this kind 
 are trifling, and the launderer need not trouble 
 himself much about them. The next step is to boil 
 the alcoholic solution carefully in order to drive 
 off the alcohol, and the remainder is then made 
 up to a definite convenient bulk and divided into 
 two equal parts. To one of these portions dilute 
 sulphuric acid (say 10 per cent) is added, to 
 decompose the soap and throw out the fatty acid, 
 and the whole is passed through another filter, 
 which has been previously weighed. When the 
 fatty acid is all on the filter, it is carefully washed 
 down with hot water to bring the fatty acid 
 towards the centre of the filter and at the same 
 time remove any traces of sulphuric acid, which 
 would char the filter if allowed to dry upon it, 
 and thus affect the weight. The glass funnel with 
 the filter is now placed in a warm place to dry, 
 and when sufficiently so, the filter is carefully 
 removed from the funnel, placed on a porcelain 
 dish, and put to dry properly in the double sauce- 
 pan kept at boiling point. This must be weighed 
 and re-weighed until it ceases to lose any more 
 weight, as the fatty acid has a tendency to retain 
 the last portions of moisture. The final weight 
 gives you the amount of fatty acid in half the 
 total amount of soap weighed out. Let us sup- 
 pose that this weight, less the filter and the dish, 
 
172 SIMPLE ANALYTICAL WOBK 
 
 is 1.8 grams, which represents 3.6 grams on the 
 original soap. 
 
 Having obtained these figures, we will see how 
 they work out. It was found that the weight of 
 the water in the soap was 1.3 grams. To obtain 
 the percentage composition, we multiply by 100 
 and divide by the original weight of the soap, 
 namely 5.4, which gives us 24.1 per cent of water. 
 
 Again is was found that the weight of the fatty 
 acid was 3.6 grams. Multiply by 100 and divide 
 by 5.4 gives 66.7 per cent of fatty acid. 
 
 It is not difficult to estimate the alkali present, 
 but as this requires a knowledge of chemistry, 
 which most of my readers will not possess, and 
 the amount of alkali is not an essential thing to 
 know, I will not explain here how it should be 
 done. In the soap under consideration, the alkali 
 combined with the fatty acid would be about 6.2 
 per cent. 
 
 To return to the first operation when the soap 
 was dissolved in alcohol and the mineral residue 
 left upon the filter. This can either be burnt to 
 an ash and weighed, in which case I will suppose 
 it weighs 0.12 grams, or it can be tested to see 
 what the impurities on the filter consist of. In 
 the former case, the result must be multiplied by 
 100 and divided by 5.4, as before, thus 0.12 mul- 
 tiplied by 100, divided by 5.4 equals 2.2 per cent 
 mineral matter. 
 
SIMPLE ANALYTICAL WOEK 173 
 
 Unless there is some very marked amount of 
 impurity present on the filter, it is hardly worth 
 while to make a test, but where there is a con- 
 siderable quantity, it is comparatively easy to 
 ascertain what it is composed of. In the first 
 place, we can add a drop or two of dilute acid, and 
 if it effervesces this will indicate that the matter 
 on the filter consists of carbonate of soda; if it 
 dissolves without effervescence it is probably 
 Glauber's salt; if it does not dissolve at all it is 
 either powdered talc, silica or starch (farina). A 
 simple test will show whether it is the latter; it 
 must be boiled in water for a few minutes and a 
 drop of iodine solution added; if farina or any 
 other starch be present it will be turned deep blue. 
 Farina is not often used to adulterate hard soaps, 
 but it is used for soft soaps. 
 
 In the soap under consideration, the mineral 
 residue is small and can be burnt to an ash as 
 directed. Putting together all the figures ob- 
 tained, the composition of the soap will be found 
 to be as follows: — 
 
 Water ... ... 24.1 per cent. 
 
 Fatty Acid 66.7 " " 
 
 Combined Alkali ... 6.2 " " 
 Mineral Matter ... 2.2 " " 
 
 Glycerine and other Sub- 
 stances not estimated .8 " " 
 
 100.0 per cent. 
 
174 SIMPLE ANALYTICAL WORK 
 
 The Hardness of Water. 
 
 16. In estimating the hardness of water, the 
 first step is to estimate the total hardness; then 
 to boil another portion of the water, thus remov- 
 ing the temporary hardness, due to carbonate of 
 lime, filter off the precipitated carbonate, and esti- 
 mate the permanent hardness, which is now left. 
 By subtracting this from the total, the amount 
 of the temporary hardness is obtained. The test 
 employed is known as Clark's Soap Test, a stand- 
 ard solution of soap, made up so that when the test 
 is made so many cubic centimetres correspond to 
 one grain per gallon (70,000 grains), or, by calcu- 
 lation, so many parts per 100,000. In making the 
 test, a clean stoppered or corked bottle is taken, 
 capable of holding, say 250 c.c. and 50 c.c. of the 
 water to be tested is placed in it. The standard 
 soap solution is then run in from a burette, a little 
 at a time, the bottle being shaken vigorously after 
 each addition. As soon as a lather which will re- 
 main for five minutes is obtained, the amount of 
 standard solution used is read off and by compar- 
 ing with the table (see page 179) the figure for the 
 total hardness is secured. A fresh portion of 50 
 c. c. is then taken and boiled in a beaker flask for 
 five or six minutes to expel the carbonic acid gas ; 
 the precipitated carbonate of lime is filtered off; 
 the filtrate being allowed to run into the same 
 
SIMPLE ANALYTICAL WOBK 175 
 
 bottle used for the first test, which has been made 
 clean in the meanwhile, the liquid which satu- 
 rates the paper in the filter being washed into 
 the estimating bottle with distilled or condensed 
 water. The hardness is then estimated in the 
 boiled water in just the same way as before and 
 the amount of soap solution used compared with 
 the table. This gives the permanent hardness, 
 due to sulphate and chloride of calcium (lime) and 
 magnesium. By subtracting the figures for the 
 permanent, from that for the total hardness, the 
 figure for the temporary hardness is obtained. 
 Many other analytical operations can be carried 
 out with the chemicals and apparatus, but too 
 much space would be required to explain the modus 
 operandi and methods of calculating results. Those 
 who wish to go further into this matter should 
 consult Sutton's Volumetric Analysis and other 
 text books on analytical chemistry. 
 
 Apparatus and Methods. 
 
 The apparatus which would be required to start 
 with for doing simple analytical work would be : 
 
 Price. 
 s. d. 
 
 1. Six beaker flasks (assorted) ... 2 6 $ .60 
 
 2. Six test tubes (a ''nest") and a 
 
 small test-tube stand ... 1 .24 
 
176 SIMPLE ANALYTICAL WORK 
 
 3. Three glass stirring rods ... 6 .12 
 
 4. Two burettes and a burette 
 
 stand 8 6 2.04 
 
 5. Six porcelain basins ... ... 1 3 .30 
 
 6. A small gas ring 3 .72 
 
 7. An iron tripod stand ... 7 .14 
 
 8. A piece of wire gauze and 
 
 asbestos millboard ... 1 .24 
 
 9. A simple balance and weights 
 
 from 50 grm. to 0.01 grm. ... 7 1.68 
 
 10. Two glass funnels and filter 
 
 paper ... ... ... 1 .24 
 
 11. 100 c. c. graduated vertical 
 
 measure ... ... ... 1 10 .44 
 
 12. Two graduated pipettes up to 
 
 10 c. c 2 .48 
 
 13. Dropping bottle for phenol- 
 
 phthalein solution ... 04 .08 
 
 14. One doz. N. M. bottles ... 4 .96 
 
 Chemicals. 
 
 Hydrochloric Acid (pure) 1 W.Q.' 
 
 Ammonia .880 1 W.Q. 
 
 Acetic Acid 1 W.Q. 
 
 Sulphuric Acid ... 1 W.Q. 
 Oxalic Acid 71bs. 
 
 *W.Q. stands for a Winchester Quart, holding 51bs. to lOIbs. 
 according to contents. 
 
 1 8 
 
 .40 
 
 2 1 
 
 .50 
 
 1 5 
 
 .34 
 
 2 11 
 
 .70 
 
 3 3 
 
 .78 
 
SIMPLE ANALYTICAL WOEK 177 
 
 Carbon tetracUoride . . . 
 
 1 W.Q. 
 
 7 
 
 
 
 1.68 
 
 Alcohol 
 
 1 Pint 
 
 
 
 6 
 
 .12 
 
 Potassium ferrocyanide 
 
 y4ib. 
 
 
 
 3 
 
 .06 
 
 Potassium Iodide 
 
 1 oz. 
 
 1 
 
 3 
 
 .30 
 
 Iodine 
 
 ^/oOZ. 
 
 
 
 6 
 
 .12 
 
 Standard Soap Solution 
 
 1/0 litre 
 
 2 
 
 9 
 
 M 
 
 Caustic Soda 
 
 1 lb. 
 
 
 
 5 
 
 .10 
 
 Phenol-phthalein 
 
 50 c.c. 
 
 1 
 
 
 
 .24 
 
 Methyl-Orange 
 
 50 c.c. 
 
 
 
 6 
 
 .12 
 
 Litmus paper, six books, red 
 
 
 
 
 and blue . . j 
 
 . • • 
 
 
 
 9 
 
 .18 
 
 I have allowed much larger quantities of hydro- 
 chloric acid, ammonia, etc., than would be re- 
 quired for experiments, as these will be found 
 useful for removing stains, etc. 
 
 A convenient strength for the acids and alkalies 
 is 10 per cent. These with the exception of 
 caustic soda and carbonate of soda, should be 
 placed in stoppered bottles, holding, say, eight 
 ounces. The indicators phenol-phthalein and 
 methyl-orange, which show whether a solution is 
 acid or alkaline, are best placed in dropping bot- 
 tles, so that it is easy to place one or two drops 
 where you want them, instead of pouring in a 
 dozen drops. 
 
 The form of burette with a piece of rubber tub- 
 ing, a pinchcock and a glass nozzle, is the cheap- 
 est, and perhaps, the most convenient. In work- 
 
178 SIMPLE ANALYTICAL WORK 
 
 ing with a burette, it is first of all filled up nearly 
 to the top with the standard solution, and then 
 sufficient is run off to drive the air out of the rub- 
 ber tubing where the pinchcock is; the level can 
 then be read off. 
 
 There are two forms of pipette, one which 
 measures only a definite quantity, say, 10 c.c.,* 
 another which measures 10 c.c, say, when full; 
 but is graduated all the way up, so that any 
 quantity up to 10 c.c. can be measured with it. 
 The liquid to be measured is drawn up with the 
 mouth some distance above the required point, and 
 is retained in position by placing the finger upon 
 the orifice at the top. By slightly relaxing the 
 pressure of the finger, the liquid is allowed to run 
 down to any desired point. 
 
 Although a thin glass vessel containing liquid 
 will not crack, as a rule, when placed over a 
 naked gas flame, it is much safer to interpose a 
 piece of wire gauze or asbestos millboard between 
 the bottom of the vessel and the flame. 
 
 In all chemical operations, it must be borne in 
 mind that scrupulous accuracy and cleanliness 
 are necessary to any approach to an accurate 
 result. 
 
 *c.c. is an abbreviation of cubic centimeters. 
 
APPENDIX A. 
 
 Table stowing the chemically equivalent quanti- 
 ties of the different kinds of alkalies. 
 
 Soda Ash, 58 
 per cent Alkali, 
 (Dry Carbon- 
 ate of Soda.) 
 
 1.0 
 0.4 
 0.9 
 0.7 
 
 Washing Soda 
 (Soda Crys- 
 tals). 
 
 2.7 
 1.0 
 2.4 
 1.8 
 
 Caustic 
 70 per 
 
 Soda, 
 cent. 
 
 Pearlash 
 
 (Carbonate 
 
 Potash). 
 
 1.1 
 
 
 1.5 
 
 0.4 
 
 
 0.6 
 
 1.0 
 
 
 0.4 
 
 0.8 
 
 
 1.0 
 
 of 
 
 Suppose you wish to change from washing soda 
 to 58 per alkali, you see that 10 lbs. of wash- 
 ing soda can be replaced by 4 lbs. of 58 per cent 
 alkali; consequently for every 10 lbs. of washing 
 soda you have been using you must now only use 
 4 lbs. of 58 per cent alkali. 
 
 APPENDIX B. 
 
 Table showing the amount of alkali required to 
 soften washing water. 
 
 f Hardness. 
 
 Amount of Dry Soda 
 
 (58% Alkali or 98% 
 
 Carbonate of Soda) 
 
 required to soften 100 
 
 gallons in ounces 
 
 Avoirdupois. 
 
 Amount of Washing 
 
 Soda (Soda Crystals) 
 
 required to soften 100 
 
 gallons of water in 
 
 ounces 
 
 Avoirdupois. 
 
 5 
 
 11/4 
 
 3% ' 
 
 10 
 
 21/2 
 
 71/2 
 
 15 
 
 334 
 
 111/4 
 
 20 
 
 5 
 
 15 
 
 25 
 
 6V4 
 
 18% 
 
 30 
 
 71/2 
 179 
 
 221/2 
 
APPENDIX C. 
 
 Table showing the hardness of natural waters 
 equivalent to the amounts of standard soap solu- 
 tion required to produce a permanent lather (see 
 page 149) calculated as calcium carbonate. 
 
 Parts of Calcium 
 C. C. Soap Soln. Carbonate (Chalk) 
 
 per 100,000. 
 
 0.7 0.0 
 
 1.0 5 
 
 1.5 1.3 
 
 2.0 2.0 
 
 2.5 2.6 
 
 3.0 3.2 
 
 3.5 3.9 
 
 4.0 4.6 
 
 4.5 5.3 
 
 5.0 6.0 
 
 5.5 6.7 
 
 6.0 7.4 
 
 6.5 8.1 
 
 7.0 8.9 
 
 7.5 9.6 
 
 8.0 10.3 
 
 8.5 11.0 
 
 180 
 
APPENDIX C. 181 
 
 9.0 11.8 
 
 9.5 12.6 
 
 10.0 13.3 
 
 10.5 14.0 
 
 11.0 14.8 
 
 11.5 15.6 
 
 12.0 16.5 
 
 12.5 17.2 
 
 13.0 18.0 
 
 13.5 18.8 
 
 14.0 19.6 
 
 14.5 20.4 
 
 15.0 21.2 
 
 15.5 22.0 
 
 16.0 22.9 
 
INDEX 
 
 FAGB. 
 
 Acetates— Cellulose 114-129 
 
 Acetates — Cellulose and Feculose 114 
 
 Acetic Acid 48 
 
 Acetic Acid — Use of 47 
 
 Acid — Actioa on Starch Ill 
 
 Acid — ricric (Nitrate of Phenol) 141 
 
 Acid — Test for 164 
 
 Acids 42 
 
 Acids, Allsalies and Salts 30 
 
 Acids and Alkalies in re. to Stains 81 
 
 Acids — Strong and Weak 43 
 
 Adulterations of Soap 57 
 
 Air — Its Component Parts 26 
 
 Albuminous and Blood Stains — Removing 89 
 
 Alcohol 96 
 
 Alizarine (Madder) 138 
 
 Alkali — Action on Starch Ill 
 
 Alkali — Amount Needed to Soften Water 179 
 
 Alkali— Too Much Used 38 
 
 Alkalies 29 
 
 Alkalies, Acids and Salts 30 
 
 Alkalies — Action of, in Mercerization 127 
 
 Alkalies — Action on Wool 40 
 
 Alkalies — Chemical Equivalents of 179 
 
 Alkalies— Test for 163 
 
 Alkalies Used in Washing 155 
 
 Ammonia, 26 ; Caustic 36 
 
 Ammonia Soap 61 
 
 Amyl Alcohol 96 
 
 Analysis — Apparatus for ". 175 
 
 Analysis of Soap 168-170 
 
 Analytical Work 102-181 
 
 Analytical Work — Apparatus Required 163 
 
 Analyzing — Chemicals Used in 176 
 
 Aniline Dyes 81 
 
 Apparatus for Analysis 175 
 
 Ash In Coke 121 
 
 Bad Color of Linen — Cause of 38 
 
 Beiuilne 95 
 
 183 
 
184 INDEX. 
 
 PAGE. 
 
 Benzine ; or Petrol, Benzollne, Petroleum Spirit and Petroleum 
 
 Ether 91 
 
 Benzine — Soap, CI ; Solvent Action of 94 
 
 Benzole. See Benzene 95 
 
 Bicarbonate Potassium 36 
 
 Bicarbonate, Sodium and Carbonate 33 
 
 Bleach — Making 159 
 
 Bleaches, Chlorine 72 
 
 Bleaching 68, 78 and 158 
 
 Bleaching — Nature of, 67 ; Powder 73 
 
 Bleaching with Sulphur 77 
 
 Blood and Albuminous Stains — Removing 89 
 
 Blues — Laundry 143 
 
 Borax, 38 ; In Starch 116 
 
 Burette 177 
 
 Capillary Action 17 
 
 Carbon Disulphide 98 
 
 Carbon Monoxide and Carbonic Acid 118-119 
 
 Carbon Tetrachloride 97 
 
 Carbonate of Potash 36 
 
 Carbonate Potassium 36 
 
 Carbonate, Sodium and Bicarbonate 33 
 
 Carbonic Acid and Carbon Monoxide 118 
 
 Carbonic Acid Gas — How Formed 32 
 
 Cause and Effect 13 
 
 Caustic Ammonia 36 
 
 Caustic Soda — How Formed 30 
 
 Cellulose— Acetate of 114-129 
 
 Cellulose — Action of Acids and Alkalies on 125 
 
 Cellulose — Made Into Fabrics 125 
 
 Chemical Architecture 22 
 
 Chemical Equivalents of Different AlKalies 179 
 
 Chemicals Used in Analyzing 176 
 
 Chemistry of Washroom 151, 161 and 15 
 
 Chip Soap 56 
 
 Chloride of Lime — How Made 73 
 
 Chloride of Tin — "Loading" Silk with 132 
 
 Chloride — Zinc — Destroys Cotton 130 
 
 Chlorinated Wool 133 
 
 Chlorine, 27 ; Bleaches 72 
 
 Chlorine Bleach — Test for Presence of 164 
 
 Chlorine — How Made 72 
 
 Chloroform, in Removing Stains 82 
 
 Chloroform, Turpentine and Carbon Disulphide 98 
 
 Coal — Composition of, 119 ; Valuing 122 
 
 Coke— Ash In 121 
 
 Coke — Manufacture and Use of, see Coal 120 
 
 Color of Linen — Cause of Bad 38 
 
INDEX. 185 
 
 PAGE. 
 
 Colored Goods — Washing 161 
 
 Colloids, and Crystalloids 99 
 
 Conduction and Connection of Heat 19 
 
 Copper Stains 84 
 
 Copper — Test for 165 
 
 Corn (Maize) Starch 112 
 
 Cotton and Linen — Differences 128 
 
 Cotton — Direct Dyes on, 141 ; Mordanting 140 
 
 Crystalloids and Colloids 99 
 
 Cuprammonium — See Cellulose 130 
 
 Curd Mottled Soap 55 
 
 "Curd" Soaps 54 
 
 Dangers of Carbon Monoxide 119 
 
 Deterioration of Linen— Cause of 38 
 
 Dextrin — See Starch Paste 105 
 
 Diastafor and Malt Extract 104 
 
 Diffusion 18 
 
 Direct Dyes and Mordants 138 
 
 Direct Wool, Silk and Cotton Dyes 141 
 
 Disulphide — Carbon 98 
 
 Dyeing — I'heories About 135 
 
 Dyes — Affinity of Mercerized Cotton for 127 
 
 Dyes and Dyeing 134-144 
 
 Dyes — Classes of, 137-140 ; Direct 138 
 
 Dyes — Direct Wool, Silk and Cotton 141 
 
 Dyes — Fastness of 166 
 
 Dyes— Metallic, 140 ; Natural 142 
 
 Electrolytic Bleaches 75 
 
 Ether — For Grass Stains. See Alcohol 96 
 
 Fabrics, 125-133 ; Adulteration of 132-133 
 
 Farina — Potato Starch 103 
 
 Fastness of Dyes 166 
 
 Feculose — Acetate of 114 
 
 •Fitted" Soaps 54 
 
 Flannels and Silks — Washing 160 
 
 Fuels 117-124 
 
 Gas — Making from Coal. See "Coal" 120 
 
 Gas — Suction and Producer — Making 123 
 
 Gas — Water — Making 23 
 
 Glycerine 96 
 
 Grass Stains. See Alcohol 96 
 
 Grease Stains — Removing 87 
 
 Green Stains — Removing 82 
 
 Gum Tragasol 115 
 
 Gun Cotton 129 
 
186 INDEX. 
 
 PAGE. 
 
 Hard and Soft Soaps 52 
 
 Hard Water 147 
 
 Hardness of Water 174 
 
 Heat — Conduction and Connection of 19 
 
 Heat— Effect of 11 
 
 Heat — Radiation, Reflection and Conduction of 20 
 
 •'Higher" Alcohols — See Amyl Alcohol 96 
 
 Hydrate of a Hydrocarbon — See Alcohol 96 
 
 Hydrochloric Acid 31 
 
 Hydrogen as a Component Part of Water 25 
 
 Hydrogen Peroxide 68 
 
 Ink — Printing — Removing 89 
 
 Ink — Writing — Removing 85 
 
 Introduction 7-10 
 
 Iron— Test for, 165 : Mould (Rust) 160 
 
 Iron Stains — Removing, 83 ; Testing for 84 
 
 Light — Effect of in Chemical Changes 21 
 
 Lime and Lime Soap 44 
 
 Lime Soap, 46 ; Test for 166 
 
 Lime in Water 147 
 
 Linen and Cotton — Differences 128 
 
 Madder (Alizarine) 138 
 
 Maize (Corn) Starch 112 
 
 Malt Extract and Diastafor 106 
 
 Marking Ink (Silver) — Removing 86 
 
 Marsh Gas 27 
 
 Mechanical Stoker 121 
 
 Mercerization — Action of Alkalies in 127 
 
 Mercerized Cotton 126 
 
 Metallic Dyes 140 
 
 Mineral Oils 52 
 
 Monopol and Tetrapol Soaps 62 
 
 Mordanting Cotton, 140 ; Wool 139 
 
 Mordants and Direct Dyes 138 
 
 Nascent Oxygen 70 
 
 Natural Dyes 142 
 
 Nature ol Things, The 15 
 
 Nitrate of Phenol (Picric Acid) 141 
 
 Nitrogen — Its Component Part, In Water 26 
 
 Oils— Mineral 52 
 
 Oil Soaps 58 
 
 Oil Used in Soap Making 51 
 
 Oxygen as a Component Part of Water 25 
 
 Oxygen — Its Component Part, in Water 26 
 
 Oxygen — Nascent 70 
 
INDEX, 187 
 
 PAGE. 
 
 Paiat Stains — Removing 88 
 
 Paraffins 92 
 
 Perborate of Sodium 71 
 
 Peroxide of Hydrogen 68 
 
 Peroxide of Sodium 70 
 
 Photographic Stains — Removing 83 
 
 Picric Acid 141 
 
 Pipette 178 
 
 Potash 35 
 
 Potassium Bicarbonate and Carbonate 36 
 
 Potato Starch, 101 ; Easiest to Make 109 
 
 Potato Starch ( Farina) 103 
 
 Printing Ink — Removing 89 
 
 Producer and Suction Gas — Making 123 
 
 Prussian Blue (Ferrocyanide of Iron) 143 
 
 Radiation, Reflection and Conduction of Heat 20 
 
 Reduction 76 
 
 Removing Marking Ink (Silver) 86 
 
 Removing Stains — Blood and Albuminous 89 
 
 Removing Stains — Copper, 84 ; Grease 87 
 
 Removing Stains — Paint, 88 ; Printing Ink 89 
 
 Removing Writing Ink 85 
 
 Rice Starch 110-111 
 
 Rinsing 157 
 
 Sago — See "Manufacture of Starch" 109 
 
 Salts — Alkalies and Acids 30 
 
 Scientific Methods 14 
 
 Silk, 131 ; Direct Dyes on 141 
 
 Silks and Flannels — Washing 160 
 
 Simple Analytical Work 162-181 
 
 Soaking Garments Before Washing — Reason For 12 
 
 Soap — Analysis of 168-170 
 
 Soap and Water — Philosophy of Action 17 
 
 Soap — Chips 56 
 
 Soap — Lime, 44-46 ; Test For 166 
 
 Soap — Sampling, 169 ; Soap Solution 156 
 
 Soap — Test for Free Alkali in 163 
 
 Soapmaklng — Oils Used in 51 
 
 Soaps 49-154-155 
 
 Soaps — Adulterations, 57 ; Ammonia, 61 ; Benzine 61 
 
 Soaps — Boiled Process, 53 ; Curd, 54 ; Curd Mottled, 55; "Fitted". 54 
 
 Soaps — Hard and Soft 52 
 
 Soaps — Monopol and Tetrapol, 62 ; Oil 58 
 
 Soaps — Soft, Special and Soap Powders 59 
 
 Soaps — Valuing, 63-167 ; Warnings re. Valuing 64 
 
 Soaps — Yellow 56 
 
 Soda Crystals 34 
 
188 INDEX. 
 
 PAGE. 
 
 Sodium Carbonate 32 
 
 Sodium Carbonate and Bicarbonate 33 
 
 Sodium — Displacing Hydrogen from Water 29-30 
 
 Sodium Oxide — How Formed 30 
 
 Sodium Perborate 71 
 
 Sodium I'eroxide 70 
 
 Soft Soaps 59 
 
 Soft Water — Powerful Solvent Effect of 146 
 
 Softening Water — Amount of Alkali Needed 179 
 
 Solvent Action of Benzine 94 
 
 Solvents 1)1-98 
 
 Souring 48-159 
 
 Stains and Their Removal 79-90 
 
 Stains — Material Necessary for Testing 80 
 
 Stains — Removing Copper, 84 : Grease 87 
 
 Stains — Removing Green, 82' ; Iron 83 
 
 Stains— Removing Paint, 88 ; Photographic 83 
 
 Stains — Removing Printing Ink 89 
 
 Stains — Removing Blood and Albuminous 89 
 
 Stains — Testing as to Nature of 81 
 
 Stains — Walnut ; Removing 83 
 
 Starch — Action of Alkali and Acid on Ill 
 
 Starch — Borax in, 116 ; Gelatinized 103 
 
 Starch — Granules ; Forms of 101 
 
 Starch— -Maize (Corn) 112 
 
 Starch — Manufacture of 108 
 
 Starch — Paste, 104 ; Properties of 102 
 
 Starch— Rice, 110-111 ; Sago 109 
 
 Starch— Test for Old 165 
 
 Starch — Thin and Thick — Boiling 113 
 
 Starch — Viscosity of 107 
 
 Starches and Other Stiffening Agents 99-116 
 
 Stiffening Agents Other Tlian Starch 1 15 
 
 Stoker — Mechanical 121 
 
 Suction, and Producer Gas Making 123 
 
 Sulphur Bleaching 77 
 
 Sulphur Compounds 94 
 
 Surface Action 16 
 
 Temperature 10 
 
 Temperature — Effect of, on Chemical Changes 15 
 
 Test for Acid, 164 ; for Alkalies, 163 ; for Copper 165 
 
 Test for Free Alkali in Soap 164 
 
 Test for Iron, 165; for Lime Soap 166 
 
 Test for Old Starch 165 
 
 Test for Presence of Chlorine Bleach 164 
 
 Testing for Iron Stains 84 
 
 Testing Stains for Nature of 81 
 
 Testing Stains — Materials Necessary for 80 
 
INDEX. 189 
 
 PAGE. 
 
 Tetrachloride — Carbon 97 
 
 Tetrapol and Monopol Soaps 62 
 
 Thermometer — Necessity of 10-11 
 
 Thick and Thin-Boiling Starches 113 
 
 Titanous Chloride 78 
 
 Toluene — See Benzene 93 
 
 Tragasol — Gum 115 
 
 Turpentine 98 
 
 Ultramarine Blue 143 
 
 Valuing Soaps 63-167 
 
 Viscocity of Starch 107 
 
 Walnut Stains — Removing 83 
 
 Warnings re. Soap 64 
 
 Washing — Alkalies Used in, 155 ; Colored Goods 161 
 
 Washing Materials 154 
 
 Washing Silks and Flannels 160 
 
 Water 145-150 
 
 Water and Soap — Philosophy of Action 17 
 
 Water — Composition of 24 
 
 Water —Hard 147-174 
 
 Water Gas-Making 123 
 
 Water — Lime in 147 
 
 Wool — Action of Acid and Alkalies on 130 
 
 Wool — Action of Alkalies on 40 
 
 Wool — Chlorinated, 133 ; Direct Dyes on 141 
 
 Wool — Mordanting 139 
 
 Xylene — See Benzene 95 
 
 Yellow Soap 56 
 
 Zinc Chloride — Destroys Cotton , 130 
 
267 90 
 

 
 
 
 
 
 
 
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