A Treatise on Soap-Making

Front matter

A

TREATISE

ON

Address to the Reader

TO THE READER.

THE author of the following Treatise would request the favour, that his intentions in producing this small, but, he trusts, useful piece, may be candidly imputed to his own real motives, viz. an endeavour of being useful to a large proportion of his Brethren in Trade, and not to an ostentatious show of exhibiting either his own abilities or education. Sensible of his deficiency in both, he humbly solicits, that the indulgent reader will have the goodness to take an opportunity of announcing any inaccuracies or mistakes herein apparent to his conception, which shall in due time be taken into consideration, rectified, and the favour gratefully acknowledged. Had this been the production of what is denominated a scholar, or man of education, much room might have been found for exhibiting flowers of rhetoric and learned philosophical explanations. So much, indeed, a display of these talents might have been exercised, as to render the book of more extensive magnitude, but at the same time, obscure and unintelligible to the very class for whose instruction and information it is principally intended. Wrote by a tradesman, for the particular behoof of tradesmen, all technical terms are therefore carefully avoided; or, where such do necessarily occur, an illustration generally succeeds. That this book may prove useful, will much depend upon the serious attention and strict observance of the matter therein laid down. The importance of its contents will more readily be discovered by those who have travelled a little in the path already, and have espied the darkness and dangers of the road. That great light may be thrown upon the subject, is the earnest wish and sincere desire of

THE AUTHOR.

Preface

PREFACE.

IT may appear something strange, that notwithstanding the numerous volumes hitherto published upon the different Arts, Sciences, and Manufactures, no practical account of Soap-making have as yet reached the eye of the Public. What this may be owing to, seem rather difficult to account for: it may be, that those few possessed of the secret, from a parsimonious, contracted, or selfish disposition, consider themselves justly entitled to preserve, exclusively, that which have cost them, perhaps, much time, expence, and trouble, to acquire. Another, and more favourable reason, however, may be alleged; that amongst these few, none have been urged by that degree of confidence in their own abilities, sufficient to induce them to set about a work in itself so mysterious and uncommon. Be that as it may, the author of the following pages could seriously have wished that this task had fortunately fallen to the lot of some other person much better qualified than himself. The idea, however, of retaining from our fellow-creatures that knowledge which the Great Disposer of all good have been pleased to lend us, only, is a notion so contrary to the benevolent rules of Christianity, which is, To do good and to communicate, that the author feels himself peculiarly happy in having it in his power to obey so far the sacred injunctions, as with pleasure to communicate to others what they may stand in need of, or to the extent of his abilities bestow.

To obtain the knowledge necessary to complete a Soap-maker, must at all times be attended with a very considerable expence, besides the consumption of a large portion of time. No experienced Soap-boiler would consider it at all worth his attention, to undertake the instructing, in the fundamental principles of the art, any person under a premium of One Hundred Guineas, besides the benefit of the person's labour spent in the acquirement. Common apprentices to soap-makers, acquire their knowledge from ocular demonstration only: they see how to prepare the materials, mix them together, set a cave, draw off and collect the leys therefrom, boil the same with tallow in the soap-pan:—the event ultimately is the production of soap.

They may also be instructed, under the eye of their master, or the boiler, occasionally, to finish a soap-pan. This last indulgence naturally creates in the apprentice, perhaps nearly out of his time, an impressive idea of his own finishing, or completion in the art of his trade. How wonderfully mistaken, however, many such have found themselves, when afterwards entrusted with the sole charge and management of a soap-work, I shall leave to their own ingenuous bosoms to declare. I well know from experience what I have just advanced to be a positive fact.

The following Treatise, therefore, I consider as a handsome and valuable present to Soap-makers in general.—Any person possessing the means, and having an inclination to become Soap-maker, may, with this book before him, proceed immediately to work, without danger of going wrong, provided always the rules and directions therein inculcated be most scrupulously attended to.

I have commenced, in order, at the very first principles of the profession, as supposing the reader totally ignorant of soap and its combinations, by giving a short account of the principal alkaline materials most universally made use of in the manufacturing of soap, and how they are to be treated, in order to extract therefrom the leys, or alkaline salts.

Secondly, I have pointed out how the hard materials may be analysed, or examined, in order to detect sand in their composition.

I next proceed to consider the leys, and to shew how they are to be weighed, and proved with regard to their strength, mildness, and causticity; consequently, to determine whether they are, or are not, fit for making soap.

After which I come, in course, to charge the pan, preparatory to a mak of Yellow Hard Soap, the operation of which is gone through in the most minute manner, explaining, as I proceed, every thing that may appear any ways dark to the understanding of a young beginner.

An operation of White Hard Soap, with the same peculiar minuteness, is also proceeded in, and described, with the grand secret of finishing for Pure White Soap, and how to scent or perfume the same.

It is also shown, how the perfume may be at an easy rate procured; with the method of preparing the Test for discovering the existence of an alkali in any liquid body.

After the conclusion of the observations on hard Soap, is inserted Two Experiments accurately made on White Soap, upon a small scale, with a Calculation of the Expence, Profit, &c. attending the same; and a Table, shewing at one view the neat Amount of Duties to be paid to the Excise on any number of inches in the frame, from one to one hundred, and by which any other quantity, or number of inches, may be discovered.

For the benefit of those who may not be acquainted with casting up the same, a specimen of the work is also subjoined.

I then enter upon the operation of Soft Soap, exhibiting and explaining several makings as they actually took place, with descriptions of leys, &c. By way of Appendix, and what is most essentially necessary for every Soapmaker to be intimately acquainted with, I have selected Abstracts of the principal Laws of Excise, peculiar to Hard and Soft Soap-makers:—The whole comprising a complete System of Soap-making, comprehending everything needful in the trade for the Soap-boiler to be informed of.

The Author has only further to observe, that in prosecuting his business as a Soap-maker, he was uniformly in the practice, from an early period, of taking down notes in writing of every particular, or uncommon circumstance, that appeared to him material, in the course of his operations.

These remarks, for his further satisfaction, he from time to time submitted to trial, by various experiments upon a small scale: And by thus persevering, he flatters himself to have acquired a tolerable knowledge of the different phenomena so universally attendant on, and inseparably connected with, the process of Soap-making; thereby rendering the whole at once clear, plain, and comprehensive.

In reviewing of late his jottings, he was forcibly impressed with this idea, viz. that these remarks and observations, being the result of above five-and-twenty years practical experience, might be of advantage, if made public, to the generality of his Brethren in Trade, especially those who have not had an opportunity of being properly instructed in the fundamental principles of Soap-making.

These principles the Author considers to be a thorough knowledge of the nature and qualities of the original materials, leys, &c. used in the manufactory. It may in general be observed, that all bodies possessing a fixed alkaline salt, may be rendered useful in the making of Soap; but the chief, and what is commonly resorted to, are the following, viz. Kelp, Barilla, American and St Peterburg, Pot and Pearl Ashes, Dantzic, English, &c.; with a short Account of which, from the best authorities, we shall commence this Treatise, and conclude the whole with a brief Dissertation on Spoiled Hard Soap, &c.

Treatise on hard and soft soap-making

A

TREATISE

ON

HARD & SOFT SOAP-MAKING.

ALTHOUGH it is not absolutely needful that soap-makers should know where, and how, their materials are originally produced; yet it is essentially so, that he be acquainted with what is more intimately connected with his own real interest; that is, how to detect frauds therein when made, and be enabled to judge of the strength, quality, and fitness of such materials for his purpose, when prepared and brought to market.

These necessary precautions known, will guard the manufacturer at all times against every imposition, whether attempted in quality or price.

To obtain a perfect knowledge, or as much information with regard to alkaline salts as possible, ought to be the principal study of the soap-boiler. The whole art of the trade, the sole prospect of aggrandisement, depends upon, and must accrue from such knowledge well digested.

As the making of soap is the avowed purpose of this Treatise to explain, the doing so, by barely exhibiting the method of treating the materials in a soap-work, preparatory for using; of charging, boiling, and finishing a pan of soap, only, would be doing nothing; would be communicating no more information than any laboring man, with a small degree of attention, in one of those works, may soon be master of. To complete the soap-maker, a far different, and more extensive degree of knowledge is necessary. An intimate acquaintance with the alkaline materials, and their consequents, the leys, ought to be attentively cultivated, so as to be rendered perfectly familiar; the nature, strength, quality, and fitness of such reduced to a demonstration, clear and simple. After these necessary acquirements are substantiated, soap-making, with the various phenomena incident thereto, will become exceedingly plain, easy, and comprehensive. We shall therefore commence this treatise, by giving a short explanation, by way of introduction, of the different alkalis, with their source of production; avoiding all extraneous or useless matter, that could only serve to swell the book, without communi any thing of importance to the soap-boiler.

Alkalis are of two kinds, fixed and volatile. The fixed kind are subdivided into two, the vegetable, and mineral or fossile alkali. The vegetable is so called, because it is procured from the ashes of burnt vegetables; the fossile, because it is found native in some places of the earth, and is the basis of sea-salt, and, in other parts, is dug out of mines in vast quantities.

They are called fixed, because they endure a very intense degree of heat without being dissipated in vapour, so as even to form a part of the composition of glass.

The volatile alkali is generally obtained by distillation from animal substances. In its pure state, this alkali is perfectly invisible, but affects the sense of smelling to such a degree as not to be approached with safety.

The acids and alkalis are generally thought to be entirely opposite in their nature to one another.

Some, however, imagine them to be extremely similar, and to be as it were parts of one substance violently taken from each other. Certain it is, that, when separated, they appear as opposite to one another as heat from cold.

Their opposite action, indeed, very much resembles that of heat and cold, even when applied to the tongue; for the alkali has a hot, bitter, burning taste, while the acid, if not considerably concentrated, always gives a sensation of coldness. In their action, too, upon animal substances, the alkali dissolves, and reduces the part to a mucilage (or clammy, glutinous, ropy substance); while the acid, if not very much concentrated, tends to preserve it uncorrupted. If an alkaline salt, and moderately strong acid, in a liquid state, be mixed together, they will immediately unite; and, provided the alkali has not been deprived of its fixed air, their union will be attended with a very considerable effervescence, or seeming fermentation.

If the alkali has been deprived of air, no effervescence will ensue, but they will quietly mix together; but, if a due proportion of each has been added, the liquor will neither have the properties of an acid nor an alkali, but will be what is called neutral. The bringing the liquor into this state is called saturating the acid, or alkali, or, combining them to the point of saturation.

If the liquor, after such a saturation, be gently evaporated, a saline mass will be left, which is neither an acid nor an alkali, but a new compound, formed by the union of the two, and which is called a perfect neutral salt. The epithet perfect is given it, to make a distinction between the salts formed by the union of an acid and an alkali, and those formed by the union of acids with earthy or metallic substances; for these will likewise unite with acids: and some of the compounds will likewise crystallise into regular figures; but because of their weaker union with these substances, the salts resulting from combinations of this kind are called imperfect.

All acids, the volatile sulphurous one excepted, change the blue infusions of vegetables, such as violets, to a red; and alkalis, as well as some of the imperfect neutrals, change them to a green.

This is the nicest test of an acid or alkali abounding in any substance, and seems the most proper method of determining whether a solution, intended to be neutral, really is so or not.

The two great divisions of salts are, into acids and alkalis. The first of these are known by their peculiar taste, which are called acid or sour. They are not found in a solid form; neither are any of them, except the acids of vitriol, of tartar, of phosphorus, and of borax, capable of being reduced to solidity.

The others, when highly concentrated, that is, brought to the utmost degree of strength of which they are capable, always become an invisible vapour, permanently elastic, until it comes in contact with water, or some other substance with which they are capable of uniting.

For such acids the name of salts seem less proper, as we can scarcely say that a vapour which is already much more fluid than water can be dissolved in that element.

Both vegetable and mineral alkali appear to be composed of an exceedingly caustic salt, united with a certain quantity of fixed air. This may be increased so far as to make the vegetable alkali assume a crystalline form, and lose great part of its alkaline properties. But, as the adhesion of great part of this air is very slight, it easily separates with a gentle heat.

The only method of depriving it of its fixed air entirely, is by mixing an alkaline solution with quicklime.

The alkaline salts for the use of the soap-boiler, are produced from the following materials: The first of which to be noticed is that well-known article, the produce of our own sea-shores, &c. called kelp.

From the large quantity of alkali therein contained, it is very justly esteemed an excellent and useful material in hard soap-making. The best of this article is made from sea-ware, or weed, cut from the rocks of the shores at low water-mark, not under four or five years old, and distant from a communication with fresh-water rivers. All the sand ought carefully to be washed from the ware when cutting, and the remainder, if any, shaken off while drying.

Particular attention should be had that no sand be mixed in the kiln when burning. The pernicious effects of sand are twofold; first, robbing the purchaser, making him pay for sand instead of kelp; and, 2dly, what is still worse, kelp burnt with sand is converted into a kind of vitrified substance, and from which it is next to impossible for the soap-maker to extract the alkali.

Kelp is always esteemed the best which is hardest, finest grained, and free from sand or earth. Sea-ware is a most useful article otherwise, besides the making of soap: it is an excellent manure for land, for which purpose it is often applied in the maritime parts of Scotland and other countries.

In the island of Jura and Skye, it frequently serves as a winter food for cattle, which regularly come down to the shores at the recess of the tides to seek for it. In Gothland and Sweden also, the inhabitants boil it in water, and mixing therewith a little coarse meal, feed their hogs with it. And we are informed, that in Jura, and some other of the Hebrides, the inhabitants dry their cheeses without salt, by covering them with the ashes of this plant. These ashes abound with such quantity of salts, that from five ounces of them, may be procured two ounces and a half of fixed alkaline salt, that is, half of their whole weight.

But the most beneficial use which such sea-weed can be put to, in the way of œconomy, is in making kelp; a work much practised in the Western Isles, Orkney, Shetland, Norway, &c.

I shall next take notice of an article peculiarly adapted to white soap-making, although equally good for yellow. It is the produce of the kingdom of Spain, at least the best is from that country, and called

BARILLA.

The description we meet with of this plant is as follows, viz.

Barilla or baritha, the name of a plant cultivated in Spain for its ashes, from which the purest kinds of alkali are obtained.

There are four plants which, in the early part of their growth, bear so strong a resemblance of each other, as would deceive any but the farmers and nice observers. These four are, barilla, gazul (or, as some call it, algazul), soza and salicornia, or salicor. They are all burnt to ashes, but applied to different uses, as being possessed of different qualities. Some of the roguish farmers mix more or less of the three last sort with the first; and it requires a complete knowledge of the colour, taste, and smell of the ashes, to be able to detect their knavery.

Barilla is sown fresh every year; its greatest height above ground is four inches; each root pushes out a vast number of little stalks, which again are subdivided into smaller sprigs, resembling samphire; and altogether form a large, spreading, tufted bush. The colour is bright green. As the plant advances to maturity, this colour vanishes away, till it comes at last to be a dull green, tinged with brown.

Gazul bears the greatest affinity to barilla, both in quality and appearance. The principal difference consists in its growing on a still dryer, salter earth, consequently it is impregnated with a stronger salt. It does not rise above two inches out of the ground, spreading out into little tufts. Its sprigs are much flatter and more pulpy than those of barilla, and are still more like samphire. It is sown but once in three, four, or five years, according to the nature of the soil.

Soza, when of the same size, has the same appearance as gazul, but in time grows much larger, as its natural soil is a strong salt marsh, where it is to be found in large tufts of sprigs, treble the size of barilla, and of a bright green colour, which it retains to the last.

Salicor has a stalk of a deep green colour, inclining to red, which last becomes by degrees the colour of the whole plant. From the beginning it grows upright, and much resembling a bush of rosemary.

Its natural soil is on the declivity of hills, near the salt marshes, or on the edge of the small drains or channels made by the husbandmen for the purpose of watering the fields. Before it has acquired its full growth, it is very like the barilla of those in which the ground has been dunged before sowing. In these years of manuring, barilla, contrary to its usual nature, comes up with a tinge of red; and when burnt, falls far short of its wonted goodness, being bitter, more impregnated with salts than it should be, and raising a blister, if applied a few minutes to the tongue.

Barilla contains less salt than the others. When burnt, it runs into a mass resembling a spungy stone, with a faint cast of blue.

Gazul, after burning, comes as near barilla in its outward appearance, as it does when growing in its vegetable form; but, if broken, the inside is of a deeper and more glossy blue. Soza and Salicor are darker, and almost black within, of a heavier consistence, and very little or no sign of spunginess.

All these ashes contain a strong alkali, but barilla the best and purest, though not in the greatest quantity. Upon this principle, it is fittest for making glass, and bleaching linen. The others are used in making soap. Each of them would whiten linen, but all, except barilla, would burn it.

The method used in making barilla is the same as that followed in Britain in burning kelp.

The plant, as soon as ripe, is plucked up, and laid in heaps, then set on fire; the salt juices run out below into a hole made in the ground, where they collect into a vitrified lump, which is left about a fortnight to cool. An acre may give about a ton.

AMERICAN POT-ASH

Is a fixed vegetable alkali, another valuable material in hard soap-making, prepared from the ashes of burnt wood in America, Russia, &c. The process of preparation is nearly as follows.

A quantity of wood being burnt to ashes, these, while hot, are raked together into a heap, in which state they remain for ten or twelve hours. The purpose of this is, to give the embers, or black bits of the wood, sufficient time to dissolve, and be thoroughly converted into a white ash. These white ashes are boiled with water, for the purpose of extracting the salt. This water being drawn off, is again boiled, and evaporated in a broad pan, over a strong fire, until the whole is reduced to a perfect dry salt.

In this state, the salt is thrown into a proper fluxing furnace, where they are converted by a strong heat into a red hot mass. This is drawn off by means of a hole in the side of the furnace, and received into iron, or other moulds, and left to cool. When cold, the lumps are broke up, and packed in close casks for exportation, being then completely ready for use. Most other ashes of the pot kind are prepared after a similar process; it is therefore unnecessary here to say more respecting them.

There is also a second and third sort made; but these are in general so full of refuse, especially the last, as to render them of little or no consequence to soap-makers.

Having mentioned a few of the principal, and certainly the best ashes used in the manufacturing of hard soap, we shall turn for a little our attention to the mode used for detecting sand therein.

This low, dirty, and abominable fraud, is but too frequently practised, not only by kelp-burners, but barilla-makers also; that is, mixing sand with their commodity while manufacturing, and in a liquid state.

The process I have used for detecting sand is simple, and not tedious, viz. take two ounces of a fair sample from any parcel meant to be purchased; beat it down in a mortar very small, pour some boiling water upon it, and rub it well in the mortar; pour off this, and add more, and so continue until all the black light substance is gone off with the water. The sand will then be found in the bottom of the mortar, and, if surveyed with a magnifier, will resemble in appearance small pebble stones, or channel, of various colours. Dry and weigh the sand; and from the quantity contained in the two ounces, a calculation may be made for the hundred weight or ton.

A certain given quantity of water ought always to be allotted for trying this expeririment; say, one or two pints; and by weighing one pint thereof afterwards, when the experiment is finished, the quantity of alkaline salt may also be discovered which one pint of said ley contains; thus, an English pint of spring water weighs 15 oz. 3 drs. 12 gr., so that all above that weight in the rubbing water, or ley, must be supposed alkaline salt. The price of the article ought to be regulated according as the experiment turns out.

From these ashes already mentioned, the strongest and purest vegetable alkali is obtained. From other vegetables, as fern, broom, bean-stalks, &c. an alkaline salt is produced, but so impure, and in such small quantities, that no soap-manufacturer in this country can use them, with any reasonable expectation of profit.

The other ashes (although sometimes used in hard soap-making, are more proper for bleaching linen, being preferred for their whitening quality, and mildness of the alkali) are the following:

BLUE PEARL ASHES.

These appear to be a pure alkaline salt, mixed with a small quantity of vitriolated tartar and earth. Half a pound of these will give about 5½ ounces of pure salt.

WHITE PEARL ASHES

Are nearly of the same quality with the former, half a pound of them giving five ounces and seven drams of pure salt, with some vitriolated tartar and earth.

RUSSIA, OR MUSCOVY ASHES,

Have very much the appearance of slaked lime, and are, like it, friable, or may be powdered or crumbled betwixt the fingers. Half a pound of them will only give about ten drams and fifteen grains of a very caustic salt. These consist, therefore, of a small quantity of alkaline salt, united with a large quantity of lime.

CASHUL ASHES

Are of the colour of iron-stone, and extremely hard, with many shining particles of charcoal in them. They have a saline taste, with a considerable degree of pungency or prickling heat. Half a pound of these ashes being boiled in a quantity of water for twenty-four hours, and evaporated, produced only ten drams of a brown salt, having a strong caustic alkaline taste. Upon examination, they appear to contain an earth half vitrified, some lime, alkaline salt, and a quantity of sulphur.

MARCOFT ASHES

Are of a paler colour than the former, with some small pieces of charcoal in their composition. Half a pound of them dissolved in water, filtrated and evaporated, yielded only eleven drams one scruple and two grains of alkaline residuum.

The blue and white pearl ashes, discovered by experiment to be pure alkaline salts, without any considerable mixture of heterogeneous bodies, may be used in hard soapmaking, mixed with kelp or barilla, with certain success. When used alone, a large quantity of common salt is necessary; nor is the soap ever so firm and hard as when they are combined with kelp, &c.; and soap made with these ashes alone, is always apt to get softer by age. Upon this account, pearl ashes seem much better calculated for soft, or green soap, than hard. A boil, however, with these pearl ashes, after the rosin have been melted, is peculiarly serviceable for killing the tallow, (according to the common phrase); it converts the whole mass in the pan to a consistence, or thin weak soap. But this will be better understood when we come to the operation of boiling or making the soap; a process which we shall immediately set about.

Let us now suppose that every thing is ready for commencing the operation upon a moderate scale, viz. that there is a small soap-pan, capable of casting from 20 to 24 cwt. of soap, six or eight iron vats, or caves, with receivers that will contain 12 or 14 cwt. of kelp or ashes, each; that there is also kelp, ashes, tallow, lime-shells, and palm oil at hand. These are all the materials necessary for performing the operation, and finishing a pan, or making of hard soap.

The first thing to be done is, to prepare for setting a cave, viz. Break down very small about 12 cwt. of kelp, and, to make a good ley, 2 or 3 cwt. of American pot-ash may also be broke and mixed therewith. Barilla ash is generally set by itself alone. The breaking, however, of the American pot-ash, from the danger of sparks (if great care is not taken) of flying into the eyes, or lodging about the feet, &c. would be as well altered to melting down, or dissolving in boiling water, and then poured upon the other materials (just now to be mentioned), after they are put into the cave.

The kelp now broke, spread about one-sixth part of it upon the floor, or slake-pit, if there is one, upon which lay about half a bushel lime-shells, and water them. When the shells begin to burst and crack, put on another layer of kelp, then more shells, and water them; and so on, stratum super stratum, or one above the other, until there is about the quantity of 2½ or 3 American ash barrels of shells mixed with the 12 cwt. of kelp. Let this stand for the space of two hours. The cave in the interim may be got ready for receiving them, thus: Lay two rows of bricks upon the bottom, from the hole or pipe quite across to the opposite side, forming therewith a small channel, of three or four inches breadth. Cover this over with any convenient thing, such as slate, tyle, a piece of dale, &c. And to crown the whole, lay on some straw, or an old bass mat, &c. This is to prevent the grosser parts of the materials from getting in and stopping up the channel, intended only for the leys to run in. Stop up the pipe, or hole in the cave, with a pin, about which ought to be lapt a piece of paper to keep all close.