31.5.16

A Treatise on Calico Printing, Of Colour-Making, Of Fermentation and Putrefaction. End of the Compendium of Chemistry.

A Treatise on Calico Printing, VOL. I-II
Printed for C. O'Brien, Bookseller, Islington, and fold by Bew, Paternoster-row: Richardson, Royal Exchange: Murray, Fleet-Street: And the Booksellers of Manchester, Glasgow, Dublin, &c.
1792
By fermentation is understood (as partly mentioned before, see notes 12 and 33 in copper work) be a spontaneous motion in a body, by which a new disposition and combination of its parts is produced: To procure it there must be a certain proportion of watery, saline, oily and earthy parts, the must be in a temperate heat, and have the assistance of the air: And as all animal and vegetable substances contain the principles just mentioned, they are of course all to fermentation: Minerals are excluded, not being as far as can be discovered, subject to this operation.

There are three species of fermentation, the vinous or spirituous or what produces wine, and spirituous liquors; the acetous or what produces acid liquors, such as vinegar; and the putrid. or what generates an alkaline volatile salt.

The subjects of the spirituous are most fruits, seeds and grains, diluted with a certain quantity of water; by certain processes, air bubbles arise with vapours, so extremely active and pernicious that without caution the effects may be fatal, this operation, if not stopped, will proceed to the last stage, namely putrefaction; the imparities then precipitate and leave the liquor clear and transparent.

By distillation an inflammable liquor light, pleasant and penetrating is drawn from wine that has sermented, which by repeated processes become more and more rectified, and is called so irit of wine; and if considerably purified, an ardent spirit; which burns without smoak or leaving any coal: united with acids they lose their pungency, and are said to be dulcified. This ardent spirit may, however, be rectified, or en tirely dephlcgmated till it produces æther, which is so volatile that it flies off in the air, fires at the approach of a flame, and leaves not the least appearance of allies; dissolving oily matters with the greatest ease, and has a greater affinity with gold than even aqua regia has.

Besides this ardent spirit, a deal of water, oil, earth, and a kind of acid is afforded by wine, which when the spirituous part is extracted suffers no farther change: but if they all remain, the fermentation, after some time, will begin again, the liquid turns sour, and then acquires the name vinegar, but this produces no noxious vapours, nor deposits any tartar: Wine however is not alone the subject of acetous fermentation, for several vegetable, and even animal substances, not to the spirituous turn sour before they putresy: this acid has the same properties as the mineral, and has effect on the same substances that the mineral acid has, but in a weaker degree: It has a greater affinity with alkali than sulphur has, and a neutral oily salt is formed from its saturation with a fixed alkali. By its solution in spirits of wine, is produced regenerated tartar: Several saline compounds are produced by its union with calcined pearls, corals, shells, &c. it perfectly dissolves lead, converting it into a neutral metallic salt, from which is produced Sal Saturni, or Sugar of Lead, because of its sweet taste; The vapour of vinegar has that effect on lead as to produce etruss: Vinegar likewise corrodes copper, and converts it into a green rust, called verdigreas, though not commonly employed for that purpose, wine, or the rape of wine, being more used.

Tartar is a saline compound, containing earth, oil, and a super proportion of acid; it is formed in wine-casks, adhering to the inner sides, particularly in those that contain acid wines; when purified, there appears on the surface a crystal line pellicle, or sort of skin, which taken off is called cream of tartar, the crystallizations of the same liquor are called crystals of tartar, and only differ in form from the cream; and though they have the appearance of a neutral salt, yet they* have all the properties of a true acid, but weaker than any other: by calcination a fixed alkali is procured from tartar, stronger and more saline than what is formed from most other matters.

16 Boerhaave particularly, Stahl however denies it.The last stage of fermentation (though by some deemed a distinct operations (16) is putrefaction, to which state when a body is approaching, it is evident by a superior degree of heat, the effect of which, as in the preceding spirituous and acetous operations, tends to change the disposition of the particles of the body in which it is excited; though how it is brought about, is not yet discovered; but after it has undergone the change, the body seems then to contain a principle that it did not before, a saline matter exceedingly volatile, and is, when separated from the other principles of the body which produced it, either a volatile urinous spirit in a liquid form, or a volatile urinous salt in a mass. In this state, whatever difference there might have been, before in vegetable substances, none is now visible.


End of the Compendium of Chemistry.

Note, It is in different places observed, that it Would be absurd to offer positive or specific rules for the performance of the operations just treated, of, and for which, various reasons are given (see introduction to copper-work note 16, and other places) therefore according to the same principles the of thissection will be treated in a similar planner; and as the preceding part of this section was exhibited under an idea that a knowledge of chemistry should be the foundation of the practice in its fullest extent, so the following com pendium or general view of operative circumstances is exhibited as the foundation of those processes which arise from them, spreading every way into an endless variety, and which can only be conceived by long experience in the practice of them.

1. Red, yellow, and blue, are the primitive or fundamental colours, and from which, under various combinations, all colours or {hades that exist in nature that are to be procured. Black is excluded on a philosophical consideration.

2. Most colouring materials require some operation to separate or dissolve their tinging qualities; some will give no permanent colour, till the sub ject intended to be coloured is printed with some astringent, such as allum, which will secure the particles of the colouring such; such as red from madder, yellow from woald, &c. or by the addition of others the colour is varied according to the quality of the additional salts, as tartar, &c. vary the shade or colour that the allum only would procure.

3. In general the effect of colouring materials produced by certain solutions, is different from their natural outward appearance.


17 Thousands of unsuccessful attempts have been made to attain this point, but till the tinging blue and yellow substance can be so equallized in quality, or harmonized in union, it is granted it must remain undiscovered — See more on this matter further on.

(18) It is remarkable in many cases, that the deepness of the black depends on the height of the white of the substance from which it is produced, as ivory when burnt; and some materials, as madder, woad, and indigo, will turn black in their effusions, by repetitions of their tinctures, — see note 28 farther on.

(19) This brightening is too much practised, not as here meant, but merely to flush up the colours, — See maddering, and note 39 of this section.
4. No substance is yet discovered that of itself will make permanent green (17), consequently all durable ones are compounded; neither is there any black material in ule, that, of itself, gives a permanent black. (18)

5. In some cases, the colouring liquid must be boiling, in others luke-warm, and in others cold: some drugs require a certain age, and others not: the materials which form different vessels, in which, colours are made or kept, mould be considered, as well as their capacities, or the uses to which they may have been before applied.

6. In the operation of fast work, should be considered 1. the opening of the body to be coloured: 2. the colouring matter itself, and 3. the fixing of it, to which may be added, the clearing or brightning of it. (19) See the end of copper-work.

Note, Cleanliness at all times, and in every stage, cannot be too much enforced; thus if the colour maker be ever so careful, his endeavours may be rendered abortive by the careless use of sieves, pans, &c. A Colour-house should never be open to every one; and a place should be set apart for delivering out colour: for wantonness and malevolence, it is well known, has in this case great latitude.

30.5.16

A Treatise on Calico Printing, Of Earths.

A Treatise on Calico Printing, VOL. I-II
Printed for C. O'Brien, Bookseller, Islington, and fold by Bew, Paternoster-row: Richardson, Royal Exchange: Murray, Fleet-Street: And the Booksellers of Manchester, Glasgow, Dublin, &c.
1792
Earths are either ponderous; calcareous (Lime) magnesia; argillaceous (Clay;)or silicious (Crystal) They are characterized by remaining unaltered in a red heat, and of those five above mentioned no one has been yet able to decompose or transunite one into another.

Ponderous earth forms with vitrolic acid, ponderous spar, and is not soluble in one thousand times its own weight of boiling water.

Calcareous earth saturated with vitriolic acid forms gypsum, known by the property it has of forming, after a flight burning, a hard mass with water.

Magnesia saturated with vitriolic-acid; forms what is called Epsom salt.

Pure argillaceous earth with vitriolic acid forms an allum.

The abevesour hinds may be called absvbent earths but the last has the least claim.

Silicious earth is not affected by vitriolic acid, it is however dissolved by that of spar, the dia mond excepted, neither is the diamond changed by the greatest heat, if not exposed to the air.

29.5.16

A Treatise on Calico Printing, Of Animal Substances

A Treatise on Calico Printing, VOL. I-II
Printed for C. O'Brien, Bookseller, Islington, and fold by Bew, Paternoster-row: Richardson, Royal Exchange: Murray, Fleet-Street: And the Booksellers of Manchester, Glasgow, Dublin, &c.
1792
These produce jellies, which when inspissated and become solid in the cold, form glue, and by the evaporation being carried further, it becomes horn.

This jelly, or gelatinous substance, is the only true animal one; as all human parts, bones and all, are to be reduced to it; the other properties it has in common with vegetables gums or mu cilages, except Jhat the animal one makes a stronger cement: Acid, and alkalies particularly, easily dissolve animal jellies; but the na ture of these combinations is not known.

28.5.16

A Treatise on Calico Printing, Of Vegetable Substances.

A Treatise on Calico Printing, VOL. I-II
Printed for C. O'Brien, Bookseller, Islington, and fold by Bew, Paternoster-row: Richardson, Royal Exchange: Murray, Fleet-Street: And the Booksellers of Manchester, Glasgow, Dublin, &c.
1792
From the analysis of vegetable substances, it is clear they contain phlegm, an acid, alight oil, much air, and a thick oil, but none of these principles can be obtained pure by mere distillation, as their separation is only began by this process, therefore others are adopted to compleat the analysis.

Some vegetables, by analization, prove that they contain the same principles as animal substances possess, and instead of yielding an acid, a volatile alkaline only is to be obtained; probably because the acid of the vegetable suffers such changes when it enters into the composition of animals, that is, it combines with some of their earth and oil, in.such a manner as to be changed into a volatile alkali.

In burning any vegetable substance in the open air, the analysis is more rapid and compleat, burning till all its oil is consumed, and a coal remains, and this continues wasting till all its phlogiston is dissipated, what then is left is its earth and fixed alkali, commonly called the ashes. Water, the natural solvent of salts, takes all of them up that are contained in the ashes, so that by lixiviating them, nothing at last is left but the pure earth.

All balsams, as well as turpentine, are oily aromatic matters, procured by different methods from those trees which produce them; these abound with essential oils separated from the vegetable in which they exist.

Resins are distinguished from natural balsams by containing less oil, and more acid, so that they are less disposed to be fluid, and are soluble only in spirits of wjne; they however differ from each other according to the quantity or quality 6f acid to which they owe their consistence: The saline character of Benjamin is evident from its being soluble. in water, but then it must be boiling; the salt produced from it will chrystallize and may be dissolved in spirits, of wine.

Gums differ from resins in being soluble in water, but (as before said) resins are not; resin being an essential oil grown thick, and have an aromatic odour, which gums have not: the small portion of oil which gums contain, being so tho roughly mixed with their acid, does not hinder their dissolving in water, and therefore they re semble honey, and other vegetable juices, in being originally fluid, and only grown hard by the evaporation of their moisture; the same as resins become solid by losing, in the same manner, their fluid parts: but in gum-resins, the two qualities, are so blended, that each will dissolve in its proper menstruum, leaving the other entire.

Sugar, manna, and all the saccharine juices of fruits and plants, are of the nature of honey, containing a phlegm, an acid, an oil, and a coal: but differ from resiirs in not being inflammable, or will not flame till nearly reduced to a coal: All these substances are deemed natural soaps, consisting of an oil rendered mislible with water by means of a saline substance, but differ from common or artificial soaps in heaving their saline part an acid, while that of the others is an alkali: Why they are sweet, thongh containing much acid, is from the acid being intimately sheathed or smoothed by the oil: Of soap it may further be said, that alkalies or acids combined, in a certain manner with oil, produce them; for oily and saline substances combined, follow the same rules as other combinations, by reciprocally combining the properties belonging to each other, and (according to the rules of affinities) soaps are decomposed by alkalies, and alkalies by acids.

The most expeditious mode of making a soap (being Dr.Lewis's improvement on Mr.Beaume's) is, by heating the alkali red hot, then throwing it into oil of turpentine, and stirring them well together; in time, a salt crystallizes both within it, and over its surface, but its nature is unknown.

27.5.16

A Treatise on Calico Printing, Inflammable Substances.

A Treatise on Calico Printing, VOL. I-II
Printed for C. O'Brien, Bookseller, Islington, and fold by Bew, Paternoster-row: Richardson, Royal Exchange: Murray, Fleet-Street: And the Booksellers of Manchester, Glasgow, Dublin, &c.
1792
These are Sulphurs, Oils, Resins, Bitumens, Spirits of Wine, Charcoal.

All bodies, probably contain more or less phlogiston, but these are deemed ihflammable in which it abounds, but with which, at the same time, it is not so intimately blended, but that it may be driven out from them, under certain circumstances, by the intervention or rushing in of the air.

Sulphur (as said before) isthe vitriolic acid combined with much phlogiston. Oils are mineral, vegetable, or animal, and are, in general, unctuous bodies, that burn and consume with flame and smoke, containing phlogiston; which by means of an acid is united with phlegm or water, together with a certain portion of earth: Nitrous and vitriolic acid, act on oils according to the portion of phlegm which they contain.

Charcoal, or any charred matter, is what is left from the burning of any vegetable or animal matter, that has an oil united to much earth; this substance is unalterable by any other body than fire; hence acids ever so highly concentrated have no effect on it.

Resins will be spoken of in the next section.

26.5.16

A Treatise on Calico Printing, Of Semi-Metals

A Treatise on Calico Printing, VOL. I-II
Printed for C. O'Brien, Bookseller, Islington, and fold by Bew, Paternoster-row: Richardson, Royal Exchange: Murray, Fleet-Street: And the Booksellers of Manchester, Glasgow, Dublin, &c.
1792
Namely, Regulus of Antimony, Bismuth, Zinc Regulus of Arsenic.

Reg. of antimony has the brilliancy, opacity, and gravity of a metal, but like all semi-metals, crumbles under the hammer: It soon dissipates into smoak and white vapours by a violent heat; flowers of antimony are those vapours, collected toy any cold body, which stops them in their ascension.

Its affinity is greatest with iron, copper next, and then with tin, lead, and silver.

Its proper solvent is aqua regia, marine acid next, if highly concentrated and applied by distillation; The vitriolic acid-likewise dissolves it, but with the nitrous it is little more than calcined.

Liver of antimony is procured by mixing nitre with it, three parts nitre and one of antimony produces a calx called diaphoretic antimony, or diaphoretic mineral. Antimony is used to separate gold from other metals, and the precipitate from its union with an alkali, is called the golden sulphur of antimony.


Bismuth.

This substance is rather duskier than the former, and like other semi-metals is volatized with a violent heat: It mixes with and quickens the fusion of all metals, whitens them, and destroys their malleability.

Bismuth is not soluble in the vitriolic acid, but in the nitrous it dissolves with much fume: Marine and aqua regia dissolve it, but with less rapidity; alkalies, and even water only, precipitate it, forming the magistery of bismuth. In its union with sulphur it forms a compound, appearing like needles lying sideways by each other.


Zinc.

Zinc differs little in appearance from bismuth, except having a bluish cast, though essentially it differs very much: It melts the moment it grows red, soon turning to a calx; and in an augmented heat burns like an oily matter, evincing the great quantity of phlogiston which it contains.

It unites with all metallic substances except Bismuth; It is soluble in all the acids, particularly in the nitrous; sulphur has little or no power over it.

It has a greater affinity with the vitriolic acid - than iron or copper has, forming a precipitate called white vitriol, or vitriol of zinc: United with copper it makes brass, pinchbeck, &c.


Regulus of Arsenic.

This readily unites with all metals, and is the most volatile of the semi-metals, flying off even by a moderate heat: the calx is plain arsenic; the properties of which are peculiar to itself, having great volatility, having a saline character, being soluble in water, and excessively corrosive, a quality none of the other semi-metals possess: It cannot be decompounded by any acid, except when joined to metallic substances: combined with the alkali of nitre or sea-salt, if they be in a fluid state, it forms a singular saline compound, called liver of arsenic: Arsenic unites readily with sulphur, and produces yellow orpiment.

25.5.16

A Treatise on Calico Printing, Metallic Substances.

A Treatise on Calico Printing, VOL. I-II
Printed for C. O'Brien, Bookseller, Islington, and fold by Bew, Paternoster-row: Richardson, Royal Exchange: Murray, Fleet-Street: And the Booksellers of Manchester, Glasgow, Dublin, &c.
1792
These consist chiefly of a verifiable earth combined with phlogiston, and are therein fusible; they are likewise ponderous, opaque, and sparkling: a third prinqiple is contended for by some chymists, called mercurial earth, but it is doubted to exist by others.

Metallic substances readily unite with most acids, and in that case an ebullition with vapours arise; by degrees the metallic particles become invisible in their solvents, and the metal is then said to be dissolved; but, as with alkalies, an acid can only take up such a portion as is sufficient to destroy some of its properties, and to render others weaker. The affinity that metallic substances have with acids, is less than what they have with absorbent earths and fixed alkalies, so that the acid which will unite with these substances, will decompound the metalline salts, and precipitate the metal, which are then called precipitates and magesteries.

Metallic substances are 6 in number, 2 perfect viz. Gold (Sol) Silver (Luna) and 4 imperfect, viz. Copper (Venus) Iron (Mars) Tin (Jupiter) and Lead (Saturn;) Quicksilver (Mercury) is by some, called a seventh metal.


Gold.

As metals are the heaviest substances known, gold is the heaviest of all, and when pure, is unalterable in fire as far as any experiment hath hitherto proved, neither can it be dissolved by any pure acid; but only by the acid of nitre mixed with that of sea-salt, called aqua regia. Gold is likewise the most ductile and most malleable of all metals.

A remarkable circumstance, and as yet not clearly accounted for, is the fulminating quality of the precipitate by an alkali or absorbent earth, gently dried and exposed to a certain degree of heat; this is called aurum fulminans, but the acid of vitriol poured on it, will deprive it of that quality, as will likewise be the case, if it be cleared of its saline particles, which, washing it in water will accomplish.

Gold is not affected by a pure sulphur when combined with an alkali.


Silver.

This metal is the next perfect to gold, being lighter and less ductile, but like gold it resists the greatest force of fire, in which is their superiority over all metals: The true solvent of silver is the nitrous acid, the chrystals formed thereby are particularly caustic; it is likewise soluble by the vitriolic acid, if it be concentrated, but spirit of salt, and aqua regia, as well as the; other acids, are not capable of affecting it: yet in reality it has a greater affinity with both, than, with the vitriolic; for if the vitriolic or marine acid be added to a solution of silver in the nitrous, the silver will directly join it, and the precipitate procured by the marine acid, is called Luna Cornea: Fixed alkalies and absorbent earths will separate the silver from the nitrous acid, though the nitrous acid cannot act on it when mixed with an equal quantity of gold, but when in a triple proportion it can with ease: If aqua regia be employed when they are in equal quantities the separation will be effected, by the gold being dissolved and the silver left free; but the operation by aqua fortis is to be preserred, it having no effect on gold, and a little of the silver is always taken up by the aqua regia: Silver united with sulphur soon flows, and forms a mallable mass, the colour of lead: — Solution of silver in the nitrous acid stains hair, bones, wood, &c. from a brown to a black, and gives a stain to marble and other stones.


Copper.

This is the first of the imperfect metals, it resists fire a long time, unites readily with gold and silver, and is soluble in all the acids, neutral salts, and even in water; to some imparting a green colour, and to others a blue: dissolved in vitriolic acid it forms blue crystals, called blue vitriol or vitriol of copper: dissolved in aqua regia, the marine or nitrous acid, it forms a salt which does not crystalize, and runs in the air: The precipitates by alkalies or earths retain nearly the colour the solution gives: mingled with nitre and exposed to the fire, as well as the other imperfect and semi-metals, it is sooner decomposed and calcined than if presented alone: mixed with sulphur and made red hot, it soon melts and forms a new compound more fusible than alone.


Iron.

This metal stands alone for its property of being attracted by the magnet, but loses it if reduced to a calx, or converted to an earth: by repeated melting it is rendered purer than by havingonly undergone fusion, but is not malleable till after being heated red and hammered in all directions: before this process it is called pig-iron but bar-iron afterwards; and is then harder to fuse: Fusing it with articles that contain phlogiston, or enclosing it in phlogiston matters, and. exposing it thus in just a red hot state for a. certain time, it is converted into steel or hardened: Suddenly quenching it when red-hot in a cold liquor, the hardness is augmented, and that in proportion to the heat of the metal and coldness of the water; it may be brought back by cementing it with calcined bones, chalk, &c. rendering it red hot and leaving it to cool gradually, or if heated alone, and left thus to cool, the temper given to steel is destroyed. Iron being calcined turns to a yellowish crust, by losing its phlogiston, and is then called crocus martis or saffron of mars. All acids, as well as certain salts, alkalies, and water itself, operate on it, but the vitriolic acid dissolves it the readiest, rendering the solution of a beautiful green; the crystals produced by which are called green vitriol, vitriol of mars, or copperas: Ochre is, the sediment produced from green vitriol dissolved in water: Spirit of nitre dissolves iron with, ease, producing a brownish yellow, but the calx formed by this solution cannot be a second time dissolved, for having lost its phlogiston, the nitre will not act on it, neither does this nitrous solution crystallize: The solution by spirit of salt is green, the vapours of which are inflammable, as well as those caused by the vitriolic acid: the solution in aqua regia is yellow.

Iron having a greater affinity with spirits of nitre and spirits of vitriol, than either silver or copper has, if offered to a solution of either, the silver or copper will precipitate, by the acid quitting them and joining the iron: Iron filings exposed to the dew, turn entirely to a ruft, called crocus martis apeciens: united with sulphur, it acquires a great degree of susibility: Iron makes a part of almost all substances (which the magnet will discover) it is found in the caput mortuum of all vegetable substances, even in honey, the earth being supposed to be impreg nated with a ferruginous or vitriolic matter, and from thence received into vegetables, and from vegetables it passes into animals: It is the only metal that sparkles in the focus of a burning glass.


Tin.

This is the lightest of all metals, has but little ductility and runs long before it is red hot: The calx when vitrified, being mixed with some other substance is called enamel, which is differently coloured by means of other metalline calces: tin unites with all metals, but destroys their ductility and malleableness, lead excepted: Those the most ductile it effects the soonest, and in the greatest degree: Bronze and bell-metal are made from a composition of this metal with zinc: mixed with lead it produces pewter, and is used quick-silver in making looking-glasses.

The vitriolic, nitrous and marine acids have an affinity with it, but cannot easily dissolve it, as they only reduce it to a kind of calx: The proper solvent (as mentioned more fully further on) is aqua regia, and has even a greater affinity with it than with gold; Gold precipitated by this method is a most beautiful colour, and used as a red for porcelain and enamelling: It has the property of giving red colours in general, hence tin vessels are used in making fine syrup of violet. It is not affected by water as iron and copper are, but it loses its polish om exposure to the air: It readily unites with sulphur.


Lead.

This is the heaviest of all metals, gold and silver excepted, is softer than any, and except tin, melts the easiest: Vitriolic acid affects it nearly as it does silver; the nitrous acid dissolves it with much ease, and in great quantities; the crystals are of a sweet taste, of a yellqwim colour, and are not easily dissolved in water: Spirit of salt, or the salt in substance, added to the solution in nitrous acid, produces a white precipitate called plumbum cornea, which dissolves easily in water: Being melted, it hardens into a kind of horny substance, like the luna cornea (whence the name:) Lead boiled a long time in a lixivium of fixed alkali will partially dissolve: It is rendered very refractory by sulphur.


Quicksilver.

This substance is soluble in acids, but to each acid, particular circumstances are annexed; thus the vitriolic acid concentrated, and made boiling, hot, reduces it apparently to a white powder; which on the affusion of water turns yellow and is called turbith mineral.

Quicksilver is easily dissolved by the nitrous acid; the solution is clear, and as it cools. shoots into crystals: If evaporated to dryness, it pro duces red precipitate: With solution of copper the precipitate is green.

Combined with marine acid, it farms a metalline salt, the crystals of which, called corrosive sublimate, are pointed like daggers, and is the most violent corrosive hitherto discovered: from this sublimate is produced yellow precipitate: Quicksilver unites with sulphur very easily, and produces by the mere mixture, ethiops mineral: By rendering the union more perfect by a strong heat, a ponderous substance is procured called cinnabar, which finely ground produces vermillion.

24.5.16

A Treatise on Calico Printing, Of Salts in General, or Saline Substances, comprising Acids, Alkalies and Neutrals.

A Treatise on Calico Printing, VOL. I-II
Printed for C. O'Brien, Bookseller, Islington, and fold by Bew, Paternoster-row: Richardson, Royal Exchange: Murray, Fleet-Street: And the Booksellers of Manchester, Glasgow, Dublin, &c.
1792
Saline substances are combinations of earths and water, or they are combinations capable of uniting with either of them, or with both to gether, for all salts are resolvable into earth and water, and the more or less they are united to their earths, they are fixed or volatile, which circumstance makes the difference between acids and alkalies. Acids are the simplest of salts, uniting readily with water, are. sharp to the taste, and have the distinguishing property of turning vegetable blues and violets red.

Alkalies have a greater proportion of earth than acids have, and have less affinity with water, but unite violently with acids, producing an effervescence and hissing; they are fiery and acrid to the taste, and turn vegetable blues and violets green.

Neutral Salts are formed from the union of art acid and alkali, by which union they rob each other of its properties, which are then so blended that neither predominates, and which intimate union is called the point of saturation: they produce no change in the blue colours of vegetables, and are neither acrid or four, but salt, such as is the taste of kitchen salt, and are generally known by the plain general term of salts. Imperfect neutrals are those in which either the acid or alkali predominate.


Of the universal or vitriolic Nitrous and Marine Acids.

The universal acid, according to its name, is found diffused in the waters, in the atmosphere, and in the bowels of the earth, but seldom pure or unmixed with other substances; what the greatest quantity is collected from is vitriol, hence it is called the vitriolic acid; and when it contains only just phlegm enough to give it a fluid form, it is called oil of vitriol; if it contain much water, it is called spirit of yitriol; when it has not enough to render it fluid, it is called the icy oil of vitriol.

This acid combined with a certain absorbent earth, with the nature of which we are unacquainted, forms a neutral salt called allum; differing in quality according to the earths with which the vitriol is combined: An alkali being presented to allum, the acid will quit the earth and join the alkali, and from the junction of the vitriolic acid, with a fixt alkali, a neutral salt is formed, called either arcanum duplicatum, or vitriolated tartar, one of the fixed alkalies most in use, being salt of tartar. — See Maddering, and note 27.

The conjunction of this acid with phlogiston forms sulphur.


Nitrous Acid.

This is no other than the vitriolic acid combined with phlogiston, by the agency of putrefaction, at least such is the received opinion, the nitrous acid being found only in earths and stones, impregnated with matters to putrefaction; when combined with chalk, stone, marble, &c. it forms a salt, that does not chrystalize, which runs in the air, per deliquium, and is de composed by fixed alkalies, with which the acid unites and quits the earths, and from this union results salt-petre.

The most remarkable and distinguishing property of nitre is its disposition to unite with phlogiston, in its purest state, such as charcoal, sulphur and metallic substances; thence bursting into a flame with great noise, called its detonation or deflagration, in which case the acid is dissipated, and the alkali which is left is called fixed alkali.

A nitre isto be procured by dropping into spring water, a solution of fixed alkaline salt, filtrating the liquid and evaporating it to a certain degree.


Marine Acid or Sea-Salt.

In respect to the constituent parts of this acid, wherein it differs from the vitriolic and nitrous, it is not certainly known, no more than it is wherein they disfer from each other; but when combined with absorbent earth (lime or chalk) it forms a neutral salt, that does not christalize, and when dried, attracts the moisture qf the air: This acid, like the others, has less affinity with earths than with fixed alkalies, but as well as the others have, it has a greater with phlogiston; and when combined with fixed alkali it forms a neutral salt which shoots into cubical chrystals, and is inclined to run in the air.

The acid of this salt when freed from its basis, is called spirit of salt, and when containing little phlogiston, it is called the smoaking spirit of salt, from its then continually emitting vapours.

Combined with phlogiston, a kind of sulphur is the result, that takes fire on being exposed to the air, called phosphorus of urine, being generally prepared from urine.

India supplies us with another acid called bo rax, which flows and takes the form of glass, and possesses some of the properties of fixed alkali.


Lime.

Any substance that has been roasted in a strong fire without melting, is called a calx; stones, (which are substances composed of different earths) reduced to this state is called lime; this applied to fixed alkalies make them more active and renders them corrosive or caustic, and from which the common caustic stone is prepared: Lime unites with all acids, and chrystalizes with the marme, but not with the nitrous.

Quick lime attracts the air like concentrated acid, and dry fixed alkali, but not so as to render it fluid; it only takes the form of a powder, and is then called slacked lime; when once slacked, though it seem ever so dry afterwards, it requires a violent calcination to separate the water from it, which it had imbibed. Sand is mixed with it in making mortar, or it would otherwise contract and consequently crack and break.

In Chemistry it is deemed holding a middle rank between absorbent earths and fixed alkalies.

23.5.16

A Treatise on Calico Printing, Of Colour-Makings

A Treatise on Calico Printing, VOL. I-II
Printed for C. O'Brien, Bookseller, Islington, and fold by Bew, Paternoster-row: Richardson, Royal Exchange: Murray, Fleet-Street: And the Booksellers of Manchester, Glasgow, Dublin, &c.
1792

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(1) There is no avoiding thus mis-naming this operation, custom has so established it, for (as observed before) what is called colour-making is but preparing the means to procure the colour from the colouring materials (in dyeing it is really and properly called the preparation) and even in chemick colour-making, where there is not the process of boilings it is not always just; for even in that case the substance imparted to the cloth is not exactly what it will be in respect to colour when rinsed, or otherwise brought up; indeed some of those cases seems an invertion of the process, being, as in the instance of liming, brought up or struck by a non colouring article. — See note 1, to Copper-work.

It is agreed that the art or mystery of colouring various articles was in use among the ancients, and in some instances they excelled us, at least it seems our mode of operation is but little different both in respect to preparation and finishing, though some parts of their knowledge is certainly lost to us; it is however certain, that they used other substances to that arr in present use; the presumption, of this being the case, is taken from the writings of very ancient authors, particularly the Greeks, and from some who have written expressly on the subject.

The Greeks, it is certain, distinguished the operations of preparation and colouring, by terms exactly to the same import as with us, as relative to opening the cores of the of to be coloured, the consider ration of the colour, and then the fixing of it; and that in the practice astringents were used as amongst us. from them it is probable it passed to the Romans, and their colour-makers or dyers (for here the terms are to the same meaning) made use of a species of fucus, which fixed the colours as firmly as is done by any modern proces; this plant is to be found in this island, it is, however, not deemed proper for whitening of linen.

The use of allum, tartar, lime, and other astringents were known to the ancients, though perhaps not exactly for the purpose we use them; what is said of them could be introduced here at length, but for reasons, several times given, it is deemed superfluous.

(2) It is not here meant that printers are to be restrained in this respect; they undoubtedly wish for as many colours as they can procure; but the difference alluded to is, as ebserved a little before in a note, that the mere producing of colours, as with dyers, is not their only object, Calico Printers having to exhibit a certain design, consisting of flowers, figures, &c. on the cloth, therefore, unless the writer is very mistaken, here is certainly a difference.

(3)See further on, where some hints are addressed immediately to the colour maker.

(4) Here the writer, in his usual unreserved manner, intimates the entertainment he has received when he has heard some Colour-makers in discourse; what was generally advanced being mere boasts of what each other knew beyond the rest, without touching on the principles of colour-making, for almost every master printer and every colourmaker will say, and probably believes, he is possessed of some advantage in this case, over every other; by which, to consider it in a general manner, that is, in every one possessing something extraordinary; it would seem as if on the whole nothing was wanting on this side perfection, but that is well known not to be the case; and it often happens, and every master Printer is appealed to for its truth, that when recipes have been purchased, it is rarely till after many experiments they derive advantage from them, and very often nothing can be made of them at any rate.

5) This phrase is in every chemical printers mouth, and some deem it so, and perhaps in some cases it is so, if it will endure two or three walhings.

(6) See at the close of this section a few thoughts on the probable effects of an univerfally adapted chemical mode of printing, if it could be attained.

(7) This brings to the writer's recollection his having read abook, he thinks called Marshall's Minutes of Agriculture; which in point of utility to the farmer, is a thousand times beyond a dry scientifical disquisition of the subject; as it contains a great number of observations apparently transmitted to paper as they occur, some of importance, and some but trivial, (or at least as might appear so to many) but these practical observations, as such, must be evidently of use, and the more so, as they are adapted to the capacities of those for whom they were intended to be useful.
As observed in the introduction to copper-work, so here it is said of this sub ject, that the chief intention in treating of it, consists more in an attempt to enforce the consideration of its principles, than in: a wish to exhibit a number of recipe's or other similar deceptive and inefficacious modes of filling up this publication: It is however begged to be noted, that though in, this light the is affected to be treated, it is not to be understood as addressed to the scientific reader only, for that would be equally useless, in respect to those to whom it is particularly directed; as Callico-printers and those employed by them, have other considerations in plenty to attend, though people in general, and some theorists in Chemistry, think the whole business, or at least the consideration of it, is comprized in producing colours; hut at present, most printers are contented with the mode as adopted in common, or else reconcile them selves to it from not having either ability, opportunity, or inclination, to pursue it further; their view being to gain something by what is known and attainable, rather than to devote much time to the uncertain effects of speculation. Of Dyeing, it may perhaps be said, the chief matter to study and practise is this article of procuring and conveying colours; but before colour is conveyed to the cloth in printing, there ire processes to be observed and to acquire a proper knowledge of, more difficult to attain than the mere art of colour-making, according to the present accepted practice of it; and in truth, to speak from a certainty, the imperfections of printing, and even the miscarriages of printers, originate as much, or more, from their inattention to other circumstances or departments, or their ignorance of them, than merely that of colourmaking. See the observations on putting on, and at the end of the first volume.

It is however certain, notwithstanding, that from the great number who practise it, and. with some reputation, who have very little acquaintance with chemistry, there seems perhaps no necessity for it; yet in order to attain a proper knowledge of the, principles of this departments it is indispensably necessary (particularly with the affinities of saline and metallic substances) other wise the practice of it must be attended with consequences vague, tedious, and unnecessarily expensive.

However, be this statement considered as just or not, the writer, as he has all along affected to blend advice with precept, shall preface what he has to advance respecting the consideration of colour-making, by addressing himself to those who are attached to making experiments, with out any principles to direct them, which, negatively may be of some service; as by pointings out what cannot be done, and wherein so many have bewildered them selves, it may shew the fallaciousness of certain operations, and in conseqrience divert their attention from that mode;. which ultimately will not answer the desired purpose.

As to laying down rules for making colour, or exhibiting a great number of recipe's for that purpose (as observed more fully in other places), it would not avail much, but on the contrary, might do considerable injury, by throwing out a stimulus to numbers who vaguely dip into the practice of colour-making, particularly in chemical processes; and hence too frequently dedicate their time and attention to what in the end, bring disappointment and regret.

As to the modes of imparting colour to the cloth, the consideration of them is reducible to a small compass, as it concerns the principle of colour-making for Callico-printers, their preparatory mixtures not running into that great diversity, in respect to the number of shades, as among Dyers. (2) It may nevertheless be said, that one part of Callico-printing is Dyeing, though not called by that name, notwithstanding the colour is communicated but in a partial degree; dyeing being generally understood as colouring the whole extent of the subject, having; previously immersed it in the preparation liquid; but here a method must be used to convey this preparation (called colour, and by an operation, called printing) to the cloth in certain lines,shapesand bodies, so that only shapes are visible when; the work is finished; and here it is, that the skill of the Colour-maker is visible; for though, by his memory or recipe's, he is informed that certain proportions of iron liquor, allum, sacrum saturni, and so on, properly applied, produce certain effects; yet the many undescribeable circumstances necessary to be attended to, render that department so extremely difficult to support in a proper manner, that very few indeed are found adequate to it, (3) even where no attempts are made at improvements, searching for new colours, or more advantageous modes of mixtures; though in fact to attempt this (as hinted before) is the height of folly without a sufficient knowledge of a chymical analysis of what is already in practice; as without such a knowledge, experiments must be inconclusive, and there is little hope of advantage from them, but by downright chance; and this leads to observe on the many instances we have of such experimental practitioness, and their little success in proportion to the boasts (4) that have been made of procuring procuring durable colours by the simplest operations; that is, as must be understood by every one in the printing business, without being brought up in the copper; for it does not much, enhance the value of that operator, who by some addition to the articles, with which another has produced a certain colour, or by some deviation, or retrenchment from them, if he can make it bear two or three more washings, for still it cannot be called permanent, though it may be deemed sast enough. (5) But the principle of most chemick operations or false colours, being little more than certain solutions combined with certain substances; with which every dabbler in chemistry is acquainted with, it would appear like affectation to dwell much upon it; (6) every one of those that make such pretensions will most likely talk highly of his recipe's and experiments; but great indeed is the experience requisite to ascertain the effects of chemick processes, as that only can be done by bringing them into practice so as to execute a course of work with some certainty of the operations not sailing.

It is far from the writer to wish to lessen or dis courage any laudable attempts toward any improvement, but those whom he treats thus cavalierly, are of a class distinguished in the printing business by an appellation too ludicrous to be here mentioned, as it is not likely much service or improvement can be educed from their vague experiments; as for those who proceed on ration al principles, whatever may be the fate of their researches, they are, and ought to treated with adequate respect; but if they do succeed, their re putation must be in proportion; as little progress is yet made toward the point desired in proceeding, even on the most scientific grounds.

Pursuing this idea further, some will undoubtedly say, who knows what may be produced from a number of experiments, if only by mere chance? as many discoveries originate more from accident than design; but still, all this is not a sufficient apology for making experiments without certain principles at hand to proceed by, for without them, the practice must be less pleasant, less likely to be affective, and what is of great, concern indeed, less likely to be attained with little expence; but here it unfortunately happens, that of the greater number of such experimentalists, is included those, who have a smattering of the practice from having been assistants to a colourmaker, or otherwise have caught the idea for the practice, and pursue it eagerly, though under every disadvantage; another class is among principals them selves, who having ingredients at hand, rush into the practice of combining and compounding one thing with another, just in the same manner, and upon the same uncertain grounds; the consequence, undoubtedly, is much anxiety and embarrassment, with very little benefit: as for the idea (just mentioned) of some thing turning up by chance, that is too absurd to give it countenance so as to recommend a series of experiments from such a hope; but advice in this particular it is apprehended will not be of much avail, most persons in this case, imagining that if they have but opportunities of making experiments or seeing ths result of them, or what is sometimes worse, getting together a number of receipes, they may save them selves the trouble of studying the theory or principles of what they undertake; for the idea of studying and storing the mind with certain regular ideas, carrying with it that of much labour and time uselessly employed, very few indeed by choice enter into it: but waving all this, it may be said, that even in such a vague course of practice, it would not be so discreditable or unprofitable, if either class, just specified, regularly made a point of transmitting to paper the sequel of their experiments, (7) as even that would be of service, since by so doing, they might, at all times, see where and how they have failed, or where they have gained any advantage, and accordingly might afterwards proceed uponsurer grounds: but even this is seldom done, though at all times necessary, under every circumstance, indeed it cannot be of much use, unless the minutes are accompanied with proper reflections on the probable causes of their failure or success.

To all this it may however be said, there are many who cannot attend to such a mode; in fact some practitioners are hardly able to write, and Principals have in general enough else to mind to dedicate much time for that purpose; hence is another reason why little benefit is reaped from such a chaos of uncertain or inconclusive experiments.

After dwelling upon this inconclusive mode of practice and the consequent circumstances; it may not be improper, by way of illustration, to intimate in a general manner wherein such practices fail, and then a word or two will be offered as recommending a properer mode of proceeding.

It is first obserted, that the substances capable of producing colours, are almost infinite; so that the field being very large, the mere dabbler has too much opportunity of fruitlessly making at tempts: Some substances give out colours that can be removed by soap, some will oppose that, but cannot resist air; and some cannot be moved by either; now respecting substances that are not permanent or fast (according to the common phrase) and known not to be such by a number of experiments; some persons have endeavoured to improve on them by joining a durable one to them; blending them as intimately as possible, from a presumption that the weak substance would have received assistance from the other; but it has always followed that the false colouring substance soon flies off, leaving the permanent one behind: Some have endeavoured to procure a permanent one, by first putting on a fading one, and covering it afterwards with a permanent one, on a supposition that the permanent one would secure it, and by being externally situated, might defend that beneath it or within it, or at least that it would operate in that manner for some time, so that there might be a little longer durability to the fading one, but this likewise will not answer; and in the practice of using acids, some by endeavouring to mix various ones together, without knowing their qualities or affinities, have found the effect of one destroyed by the effect of the other, like solution of tin and cream of tartar, or solution of tin and sacrum saturni, as the marine acid will quit the tin and join the saccharim, the acetous acid being at the same time suspended by it, is of no effect on the tin: — see experiments of this kind further on; others have had a notion that a mixture of different salts will keep the colours better; but it is proved to have a direct contrary effect: hence when they have acted in this manner, without any positive knowledge of the principles of this part of chemistry, they have made such aeonfused mixture, that it was impossible to know which ingredient, or what number of ingredients caused the miscarriage; much less to know in which was the efficacious property sought after. Now, in this case, it may be further said, a necessary circumstance is omitted, and that is, first of all to try what effect each salt has on the colouring substance in regard to their similarity of effect or appearance, for in knowing this, thsre is the greater chance of succeeding. But, if persons will plunge them selves into a practice of making experiments, let them begin with making them first, with simple solutions or extracts upon seperate vegetable or mineral subjects, making suitable remarks upon each result; though even that will not be sufficient, unless the qualities of the solution are alike, or a previous acquaintance with them be obtained, so as to know their different effects in point of strength, or time of operation; and this implies an abundance of food for observation, from the various mixtures that may be made only, of one article used as a basis, if considered in its different degrees of strength or purity, and the different subjects it may have to act on. However, by proceeding in this simple manner, they may then unite or multiply them . But if they proceed here in too precipitate a manner, they will presently be bewildered, as it must be clear from the above statement, even to an in different person, into what numberless channels the simplest mixtures of simple s with each will run; and much more so when compound ones are taken; hence without some clute in this practice, the same indifferent observers must as plainly see, that such operators must very quickly find them selves in an inextricable labyrinth, hemmed in with doubts and difficulties, and if they proceed, it will be more from a shame of going back, than from a hope of getting into any regular channel.

In proceeding now to the intimation of a more proper mode of making experiments, it is premised, that the consideration of colours (as may be supposed) is exhibited only as relative to printing, hence it chiefly alludes to those that are permanent or fading, as applied to linen or other substances of the same kind.

By permanent colours, everyone in the printing line considers those that are not to be removed by soap, sun nor air; the othert are of various kinds, as some withstand washings, but will fly an the air; others will withstand neither, and others only for a little time; but what is of the most concern is, that, with few exceptions, those colours that are the most permanent, are the least brilliant; though for this, it may perhaps be said, that entering but into the superfices of the made use of, the colouring particles are more crouded together; and consequently exhibit thejr rays more glowingly than if more dispersed or separated; which must: be the case when entered (as is supposed in the case of permanent ones) into cells adapted to receive and retain them; and the more compound the colour is in respect to its ingredients, it is the less vivid, and less likely to be durable.

As to what bold speculatists, or even experienced practitioners may suggest, our know ledge of the nature of colouring substances is very limited; or if we know something of any substance in one state, that substance, when separated, will present a new appearance in its separated parts, and so on ad infinitium; hence, likewise is our knowledge very small indeed in judging or determining on the result of those applications of one substance with another, for the purpose of discovering or fixing of colours. In simple processes, instances are very rare of permanency, but of any combination of ingredients, when one article seems to bid defiance to the great proofs of air and sun, there is the object for investigation; and therefore in colour-making, a great point is to discover those articles that naturally possess those permanently tinging qualities, or that can easily, and in the simplest manner be procured by a combination with some other.

(8) In the Spanish seas is found a shell-fish that resembles the antient purpura, the purple dye is in its throat; Cloth of Segovia is dyed with it, and bears a high price. The colour from the fish when first laid on linen, is a light green, which by the aio is changed to a dark one — in a few minutes to a seagreen — a little while longer into a blue — from that it turns to a purplish red — and in an hour or two to a deep purple; here the sun has no more power, but by washing it in scalding water and soap, and drying it, the colour, ripens to a beautisul bright crimson.

The Americans of Peru and Chili had knots of wool, which by the variety of their colours served for characters and writing; the knowledge of these knots was called guipos, and was one of their greatest sciences.

The Otaheiteans procure a beautisul crimson by mixing the yellow juice of a species of fig with the juice of fern.

(9) Among them will be found the means of ren dering impure waters otherwise. — Detecting, sophisticated allum, tartar, and other falts, with the discovery of new ones. — Various preparations of colours, — Experiments on Prussian blue, Indigo, &c. a new green colour procured from phlogisticated copper and arsnetical acid, &c. In the Manchester Philosophical Memoirs, are enquiries in view of procuring new dyeing materials by Dr. Delaval, — on the use of acids in bleaching by Dr. Eaton. — The state of the imitative arts among the Ancients compared with their present state, by Mr. Thomas Kershaw, &c. &c.

* See this admirably exemplified in Fourcoy, vol. 4, on the of putregaction.

(10) Not being generally known, and to shew that scientific discoveries, though not directly useful, may lead to what is lo, it is said here, that the re flections on the filling of Balloons, gave rise to certain experiments on air. — It may be added for the above reason, that the effects of light on vege table and other colouring substances is such, as to give the Eastern countries their superiority in that respect, as well as their original claim.

****** In order to give persons of consined information some idea of those regions, the object of the above great Astronomer's researches, it may be said the orbit of the Herschel (originally named the Georgium Sidus) or the revolution it describes round the sun, is between 10 and 12,000 millions of miles; or above 3000 millions in diameter. Now here let the reader stop and contemplate the magnitude of this space, as occupied by the sun and the rest of the planets; or suppose it is said a sphere or globular object filling this space. — Now let him compare this vast object or occupied space, to the regions now exploring, containing millions of millions of such occupied spaces, and it must appear as a speck, a grain of dust, or a point. But further, if he considers these regions as unlimited, then this vast object, or space of above 10000 millions of miles in circumference, if compared to such unlimited space, must seem smaller than any particle of matter is (which tho' we know it exists, yet cannot perceive it by the most powersul microscope) compared to this object of above 3000 millions diameter, or above 1000 millions in circumserence ! ! !
As it is not certainly known, nor perhaps will it ever be, why some colours fade, and others will not, suppositions have been formed, spe cious enough (as already exhibited) though they are received not as being indisputable, but only as the best or most rational that can be given. The most remarkable instance of simple substances for giving out their colour, as it were spontaneously, was in the tyrian dye, (8) which had power enough of itself, simply to communicate to silk and some other substances, a colour as; firmly as can, now be procured by any process whatever: Other instances are in the solutions of indigo and silver; the latter when mixed with chalk turns the sediment to a purplish black when exposed to the sun, or rather the action of the sun's heat is the cause; the other circumstance respecting indigo, is perhaps more known to callico printers, in the solution at first appearing green, but on exposure to the air turning to a blue, as observed in another place.

Having spoken of the vague and inconclusive operations of many, the following display of the institutes of chymistry in view of establishing me on a firmer basis, is humbly offered, which will be followed by a few thoughts immediately relative to the practice of what is the of this section.

It has been said, that an acquaintance with chemistry is indisputably necessary for a colourmaker to have, but it must be understood not in every division of it; as chemistry, in its extensive signification, comprizes considerations that have little to do with the of this treatise; therefore the elementary parts and principles only will be just touched on, as leading to what is the principal object of it, that of prompting those who look at this treatise, to pursue the enquiries it recommends to wards attaining knowledge, rarher than expecting to find it in the work itself. Hence it is supposed as this little abstract can quickly be perused, and easily retained, it may incite some, from the evident insufficiency of it, to look further into the whom otherwise the generally voluminous appearance of chemical treatises would have deterred.

from the above it may be supposed, that what is exhibited in the following sketch, will be as free from contested points as possibles as well as being limited in the subjects of it. Therefore, notwithstanding that, through the numerous discoveries made, and still making, Air, Water, Earth, and Fire, are no longer deemed elements (Fire is deemed ideal) they will here be considered still as such, and the account as well as the rest of the compendium, will be chiefly taken from macquier; he standing, as it were, in the mid-way between the old and the new theories (see Fourcroy's Chemistry in the Transtater's preface.

Here it would not be unpleasant to dwell on the new discoveries and theories, as almost numberless transcriptions could be made, that, at least, might amuse: however, those who are inclined to look into the most modern authors, will find a list at the end of the work, each ol which contains more or less of what would not only entertain as theories, but as otherwise are practically proper for every Callico-Printer to consult.(9) See maddering and the last note to it. But respecting Dictionaries and other similar compilations, a few excepted, nothing is more fallacious, (see note 40 to this section) from their nature containing little original matter, and few of the new discoveries. For so many have been the opinions and facts promulgated within the last 10 or 12 years, that authors however respectable before that period, are in many points superseded; and Dr. Priestly himself declares, that theory itself is now unhinged, and Philosophers have to unstudy what they have been long labouring to acquire. Not but that the more this great arcana is per vaded, the more we discover of that wonderful connection of the whole; that rotation of effects, where nothing is displaced but its room is sup plied; and that what is called destruction is only a preparative to new combinations and forms.*

The following are some of the modern innovations and facts, represented as briefly as possible, though far from being generally received. Phlogiston, instead of residing in inflammable bodies is resident in the Air, and is an element of Water. — Air contains phlogiston and water. - Inflammable air resolvable into water not smoak. — Common air contains out of 100 parts, 27 pure, 73 phlogestic.- Water transmutable into earth. — Water contains phlogiston and acid. — Ignition a substance put into a condition to imbibe phlogiston from the air; bodies therefore by being burnt acquire weight. — Vegetables exist by imbibing phlogiston. — certain green sedgy matters purify water and keep it so. — In solutions of metals, the diluent or water is the solvent, and the metal decomposes the acid. Several of the affinities are reversed.(10) and Phlogiston generally pat at the top of each column.

In fine, the elements are now almost as much a of decomposition as any other substances.

And here, to deviate from, or, perhaps, rather to enforce the just dwelt on, as it is of sering a great counterpart of discovery, and by the contrast, rendering what has been observed the more striking; may it be exhibited as a respectful, and from the sublimity of the circumstance introduced, an aweful testimony that the present glorious epoch of knowledge transcends all previous human efforts; as taking all nature, as it were, into its grasp, and collapsing the extremes of creation? For, while philosophy on one hand, bursting through the elementary barriers of nature, pursues her to her inmost recesses and analyzes those objects, whose minuteness confound the imagination, and which are only perceptible by their effects; on the other hand, it not only adds new orbs to our solar system, but darts into the immeasurable expanse and scrutinizes objects that as equally confound by their magnitude, and the spaces they possess; in short, it can be said, it explores immensity itself, gages the very Empyreum, and exhibits its construction ! ! ! ! ! — But of this stupendous effort, the writer dare not venture to say more, as he scientific analyzers of literature the:nselves, while they subscribe to the success of it, follow the explorer with timidity, and investigate his pursuits with astonishment! ******

This erratic descant is therefore closed with informing the reader, the whole is to be found in the memoirs of the Royal Society, 1785, as delivered in by Dr. Herschell; and the writer proceeds to the Compendium, beginning with the elements according to the positions just suggested; and first, of

AIR,

Air it need hardly be said, is that fluid which surrounds our globe, and pervades all bodies not filled with a heavier substance than itself. Its chief and distinguishing quality, and from which results the general effects of it, is its elasticity or spring, or its property of expansion and rarefaction, according to the presence of fire and heat. Its weight is about 800 times lighter than water; or a quantity of water 1 cubic inch in bulk will require 800 times that bulk of air to be of the same weight, taking the air in its common state, the bulk as before said, beingv continually susceptible of change.


WATER.

This is a transparent and insipid substance, and fluid or solid according as affected by heat or the privation of it; its natural state is supposed to be solid, and rendered fluid only by heat; exposed to actual fire, it acquires a certain heat (by boiling) beyond which the greatest force of fire can never raise it; the effects of dilatation' (as when a small quantity is thrown upon metal in fusion) are occasioned by the air it is supposed to contain, and like air it enters into the com position of most bodies, except metals and mi nerals, as it is only supposed to be interspersed between their parts, without entering, into their composition.


EARTH.

This element is different from those just mentioned, in being fixed; they being volatile, or easily separated by the action of fire, from the bodies with which they may be united; hence earth absolutely pure cannot be affected by any operation, and resists the utmost force of the strongest fire, being the caput mortuum, or that substance left after a chymical process, which to all perception cannot afterwards be changed. Earth may however be divided in respect to its qualities, into vitrifiable and unvitrifiable; one that will melt by fire and become glass, and the other that will remain unaltered, such as sands, which are likewise called absorbents, from their quality of imbibing liquids.


FIRE.

This element is divisible into that which is concluded to originate from the sun, and that which is called phlogiston, as being universally held a constituent part of any body: that coming from the sun may be called a fluid substance uninterruptedly flowing from him, and diffusing itself through the whole planetary system, and every particle of matter in it, but not as a native principle; hence it may be supposed the air itself would become a solid mass without this interve ning and active principle; its rarefaction and condensation, with the dilatation of water, and similar effects produced in the earth originating from it; and in all our eperations it is the most powerful agent, and when collected in the focus a large lens, is at the greatest possible height producible by human art.

What is understood by phlogiston seems to be different, being apparently fixed to all bodies, so asN to make a part of them; but how so active, or, as it were, so restless a substance can be so fixed, is not yet determinable, as it differs from elementary or pure fire (just spoken of) in communicating neither light nor heat when joined to any other substance, and produces no change in its state; so that a solid body becomes not fluid, nor a fluid solid, by its absence. The sign ot any substance containing phlogiston, is its being capable of taking fire; but, as in the case with metals which abound with it, and which are not inflammable, it is not thence inferred the have none. Thus a body may be said to contain its phlogiston, when after a flame subsides it sparkles or wastes, till reduced to a coal; and, adverting to the of colours, it is known, that the number which we perceive is owing to the varied combination of phlogiston, with oils, earths, and salts.

(11) So deemed as; containing an analyzation of substancei more simple than what they help to form, and are yet composed of primary principles.The next general consideration is, that of secondary principles, (11) which are constituted chiefly of saline and oily parts; and as all the experiments that have been made, prove there is such a mutual agreement, connection, or dependence on one part with another, the knowledge of what substances thus agree or disagree, under their various combinations, forms (as must be clear to every one, and which has been repeatedly enforced) the foundation of some certainty in making experiments for any purpose whatever; but before that can be known, in respect to particular substances, the nature of this universal afsection should be conceived, and likewise what are the affinities of the different classes of substances which comprehend the species belonging to them; therefore the following postulata or propositions received as fundamental truths, (similar to axioms in mathem aticks, or maxims in common life;) and the table or scheme of affinities which will afterwards follow, have been formed far that purpose.

1. Any substance having a conformity with an other, the two will unite and form one compound.

2. All simple substances have affinity with each other, and will consequently unite; such as waterwith water, fire with fire, &c.

3. Substances when united together lose some of their respective properties, and the compounds resulting from their union partake of the properties of those substances which served as their principles.

4. The simpler substances are, their affinities are more perceptible; hence it is most difficult to analyse bodies that are the least compounded.

(11) Thus if you pour vitriolic acid on common salt, the mineral alkali having a greater attraction for the vitriolic acid than for the marine; leaves the latter and unites with the former. The vitriolic acid is also said to have a stronger attraction for the mineral alkali than the marine acid has: hence the former acid is said to expel the latter from its basis; or it may be said demonstratively thus; If A being united with C, upon B's being after wards applied to them, lets go C and joins B, A is said to possess a greater attraction for B than C.

(13) Thus when pure calcareous earth (lime) is dissolved in the nitrous acid (aqua fortis), a caustic volatile alkali will hot disunite them, because the attraction of the alkali with the acid is not so strong as that of the calcareous earth.

(14) Thus, to pure calcareous earth dissolved in nitrous acid, (as above) let ærial or vitriolic acid be added, and the effect is obtained; the ærial acid acting en the earth on one hand, while the alkali acting on the nitrous acid on the other, diminishes the cohesion of the earth with the nitrous acid to such a degree, that the volatile alkali is now able to unite itself with the latter acid, and expel the earth.

(14) It may be intimated, that all Chymists to not agree in the justnesss of these affinities in particular cases, for in this instance (as well as in the instance of printing, and indeed in all human sciences) circumstantial differences will ever Happen, since the perceptions of hardly two persons are affected alike.
5. If to a compound, consisting of two substances, a third be added that has no affinity with one, but has a greater with the other, than the first; 2 combined have with each other, a new decompounding, and a new union must ensue.(11)

6. A third substance offered to a body consisting of two, no decomposition may follow; but the two uniting with the third, without quitting each other, may form a union of three principles; presuming the third substance has an affinity, or nearly equally so with each of the other substances. (13)

7. Though a compound consisting of two substances, having a greater affinity with each other than with a body presented to them, may not be decomposed by it; yet that body, when combined with another, having an affinity, with it, compensating for its want of it with the others, may separate the two, by uniting with each of them; therefore in this case there is a double affinity, a double decomposition, and a double combination. (14)

What next follows is a table of affinities, or elective attractions, of one substance to another, or a more specific representation of the substances just alluded to, in the relation they are observed to have with other as productive of those appearances that ensue by their operation on or with each other; the substances in each column or division are placed in the order they agree with that at the top: thus in the first division, Vitri olic Acid stands at the top; accordingly the substance that has the nearest affinity to it is Phlogiston; Fixed Alkali has less than Phlogiston; Calc. Earth less than Fixed Alkali, and so, on. (15)

Vitriolic Acid |
Phlogiston
Fixed Alkali
Calcareous Earth
Zinc
Iron
Tin
Copper
Quicksilver
Silver
Volatile Alkali
Magnesia
Earth of Allum

Nitrous Acid.
Phlogiston
Fixed Alkali
Calcareous Earth
Zinc
Iron
Lead
Tin
Copper
Quicksilver
Silver
Volatile Alkali

Marine Acid.
Fixed Alkali
Calcareous Earth
Zinc
Iron
Lead
Tin
Copper
Reg. of Antimony
Quicksilver
Spirits of Wine
Volatile Oils
Gold

Sulphur
Fixed Alkali
Calcareous Earth
Iron
Neckel
Copper
Lead
Tin
Reg. of Ant.
Quicksilver
Arsenic

Liver of Sulphur is partially composed by
Quickssilver
Solution of Fix. Alk.
Lime Water
Vol. Alk.

Fixed Air.
Calc. Earth
Fix. Alk.
Magnesia
Vol. Alk.

Alkaline Salts.
Vitriolic Acid
Nitrous Acid
Marine Acid
Acetous Acid
Vol. Vitriolic Acid
Sedative Salt
Fixed Air
Sulphur
Expressed Oils

Calcareous Earth.
Vitriolic Acid
Nitrous Acid
Marine Acid
Acid of Tartar
Acetous Acid
Sulphureous Acid and sedative salt
Sulphur

Metallic Substances, Lead and Red. of Ant. excepted.
Marine Acid
Vitriolic Acid
Nitrous Acid
Sulphur and
Acetous Acid.

Lead.
Vit. Acid
Mar. Acid
Nit. Acid
Acet. Acid
Expressed Oils.

Reg. of Ant.
Vit. Acid
Nit. Acid
Mar. Acid
Acet. Acid

Arsenic.
Zinc
Iron
Copper
Tin
Lead
Silver
Gold

Reg. of Antimony (with Metals.)
Iron
Copper
Tin
Lead
Silver
Gold

Quicksilver
Gold
Lead and Tin
Copper
Zinc, Bismuth, and Reg. of Ant.

Silver.
Lead
Copper
Iron

Water.
Fix. Alk.
Spiris of Wine
Mild Alk. Salt and
some neutrals

Spirit of Wine.
Water
Oils and Refins.

In consequence of heat, sedative salt decompose tartar and sea-salt, phosphorus acids decompose vitriolated tartar, nitre and sea-salt.

Instances of double elective attractions.

As where the two compounds being mixed, those opposite to each other, as they are here exhibited, unite and form double affinities.

Acids. Calcareous Earths, or Metallic Substances. | Vol. Alk, Fixed Air
Vitriolic or Marine Acid. Alk. or Earth. | Mercury, Silver, or Lead. Nit. Mar. Acid
Lead., Nit. Mar or acet. Acid | Vit. Acid, Alk. Earths or Metallic Substances
Silver, Vit. Mar. or acet. Acid | Fixed Air, Fixed Alk.
Vit. Mar. or acet. Acid | Vol. Alk. Magnesia, or Earth of Allum; Vit. Acid.

Instances in Fistillations and Sublimations, and that require heat.
Vol. Alk., Acids. | Fixed Air, Calc. Earth
Vol. Alk., Vit Acid | Nit. Mar. or acet. Acid., Fix. Alk.
Vol. Alk., Nit. Mar. or acet. Acid. | Acet. Acid., Fix. Alk. or absorbent Earths.
Reg. of Ant., Sulphur | Mar. Acid., Quicksilver

Instances in Mixtures by Fusion
Tin, Silver | Iron, Lead
Copper, Gold | Sulphur, Lead
Metallic Substances, Gold |Sulphur, Reg. of Antimony

The affinities or attractions here displayed wre either in the humid or dry way; the humid is, when one, at least, of the substances is fluid in the heat of air, or a heat but little beyond; the other is, when to produce a fluidity, the application of burning fuel is necessary.

Example in an instance of single attraction.
Apply to cinnabar and iron filings, a certain heat; the mercury of the cinnabar will rise, and leave the brimstone, its other element, combined with the iron, which it attracts in preference to the mercury.

Example in an instance of double attraction.
Unite mercury with common salt, by means of a like certain degree of heat, a new compounded combination will commence among the substances: by the marine acid of the common salt joining the quicksilver of the mercurial salt, forming a new salt called corrosive sublimate, while the mineral alkali of the common salt unites with the vitriolic acid of the first mercu rial salt, and forms what is called Glauber's salt.

22.5.16

A Treatise on Calico Printing, Of Grass-bleaching, or Fielding.

A Treatise on Calico Printing, VOL. I-II
Printed for C. O'Brien, Bookseller, Islington, and fold by Bew, Paternoster-row: Richardson, Royal Exchange: Murray, Fleet-Street: And the Booksellers of Manchester, Glasgow, Dublin, &c.
1792

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(35) Perhaps inhalation by the air may be mote proper, evaporation being more applicable to a chemical process.

(36) It is here offered as an opinion, that parks should be sloping from the middle.
Having spoken of bran - bleaching or souring as subsequent to maddering, and observed (in a note) that by the improved mode of branning but a few pieces at a time, a white is almost procured without laying the pieces down (though that it need not be said is not proper to be done in all cases) it remains now to speak of laying cloth down to clear the ground or other parts, from the superfluous particles of colour; it is therefore observed that this effect appears to be chiefly accomplished by evaporation(35) and most effectually in sun-shine and moderately windy weather, she heat of the sun opening the pores and thereby giving egress to the colouring particles, detained in them till then; but in dull wintry weather, it is well known, the process of whitening goes on very slowly; there being no power by heat to dislodge those particles; for without it, watering is insufficient; the use of that operation being only to advantage when combined with the heat of the sun; one power infinuating itself into the pores of the cloth, and the other continually exhaling the watry particles, bringing away every time, some of the superfluous colour, and leaving those that by the action of the binding or contracting quality of the acids are with-held; though even these it is known, were the process carried on too long, would be removed in some degree; especially if the work consist of pale or tender colours.

It has been before said, that attention should he bestowed on the quality of the water, that it be light, soft, and free from filth; it likewise is necessary to attend to the quality of the soil of the field; for the facility and success of the operation depend on the mutual action of heat and watering,; therefore the drier the soil, or the more gravelly it is, the water will sooner pass through.it, and the heat on the surface will not be so much opposed as otherwise. (36) Smoke jar vapours from very foul boggy places, may be said to be injurious, if frequent, and in great quantities.

It is noticed, that cloth does not get white so soon in windy weather as in still sunshine; therefore, it appears that its influence penetrates the inward parts by its evaporating power, while wind only dries it, and in a manner prepares it; for succeeding operations of watering; for wind, alone, especially if cold, would close the pores of the cloth; but the power of heat naturally acts to the contrary; and in the case of evaporation, if seems the particles are partly dislodged by water, and then finally drawn out as those particles rise up.

In many places on the Continent, strange as it may seem; the printed goods are never watered, and to this dry bleaching it is owing that in most foreign printed goods, little colour is seen in the back, particularly in what is called Swiss chintz; but then the texture of the cloth is unavoidably nearly destroyed.

It is a particular circumstance to attend to in printing grounds, where printed goods are watered (which the writer thinks is every where the case in this country) that the water be not hard, nor tinged by any mineral quality; one reason for not watering, on the Continent, may be, the waters there abounding, with mineral imipregnations; indeed about London, work done in some places, is clearer in the white, from the superiority of the waters; and it is well known the soil in general in the north, from its mineral quality, is unpropitious to producing a good white, and without a good white no work can appear perfect.— See note 6.

(37) This may be considered philosophically as well as merely mechanically, the sensation of colours being caused by certain reflected coloured particles, or rays of light striking the eye, according as certain substances are disposed to receive those particles, thus, a bright colour lying by a dull one, the rays from each being intermixed with each other before they reach the sight, the bright colour helps to enliven the dull one, and the dull one deadens the bright one, so in painting, it is not suffieient that shadows be properly disposed, but that every colour, according to its quantity or proximity to another, communicates a portion to the parts near it, receiving at the same time, according to the laws of reflection and refraction, a portion likewise from the other.

(38) It is a pity this part is not better attended tot than it is in general, in preventing the ill-effects of high wind, as a little extra trouble would accomplish it, either by laying the work down in small parcels, or by means of moveable laths or ropes, or trees, hedge's, &c. placed as foreens.

(39) Thus, in all chemical operations, they are to be traced to the agency of the four simple elements; and, to come quite home, in producing fixtd colours on cloth; it is to be traced to the simple operation of an astringent.
That a deal depends on the soil and water is further evident in the case of foreign articles, particularly some from India; for at a place called Seconge, the waters have, it is said, a surprizing tendency to whiten the cloth, (37) and of course to render the colours more brilliant, hence goods are brought thither from distant places for that purpose, as likewise to two or three other places on he same account.

In managing the field-work, the great concern is to put those kinds of work in the same parcels, that will take the same time to be brought white; that in fine open weather they are kept regularly watered, particularly work with delicate colour, and that the water be kept free from sedge and other filth; the other common processes of laying down,(38) pinning-, taking up-, drying, &c. every common fieldman is supposed to be acquainted, with, and therefore dwelling on those circumstances is deemed unnecessary.

Before this lection is closed, it is repeated, and begged it may be remembered, that in respect to particular processes, little is offered as positive, the difference of thinking and acting among diff erent practitioners rendering, such considence absurd (see note 16) but here it may be said, that the rejection or adoption of any mode of practice, is no further demonstrative of propriety than as it is, or is net, in consequence of a rational investigation of the object, therefore those who simplisy aay set of operations, (not from parsimonious views) but on the principle that nature universally observes in the sources of her operations, is alone likely to succeed, and (as particularly observed further on in respect to experimental colour makers) deserves credit even if he be un successful; for certain it is, that in all mechanical operations, as well as natural (however complex they may appear) there is a simple point, on which they all move, or from which they spring and branch out, and from this consideration the man of acuteness and reflection, whatever may be the subject of his employment, will trace every part through its connections and dependances to this first movement, this essential point, this actuating principle, and thence back again to its ultimate intended effects, endeavouring accordingly to remove what is superfluous, and supply what is deficient; while on the other hand, the man who proceeds in the vague uninformed manner, so often reprobated in this work, soon seeling his deficiency in this requisite, chain of knowledge endeavours to compensate for it, by repeated alterations of every kind, merely in the blind hope of accidentally stumbling on what is proper. (39)

21.5.16

A Treatise on Calico Printing, Of Maddering.

A Treatise on Calico Printing, VOL. I-II
Printed for C. O'Brien, Bookseller, Islington, and fold by Bew, Paternoster-row: Richardson, Royal Exchange: Murray, Fleet-Street: And the Booksellers of Manchester, Glasgow, Dublin, &c.
1792

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(26) In menstruums, or dissolving liquids, three things are needed, 1st, that the parts of the body attract the particles of the menstruum more powerfully than those are attracted by each other other. 2d, That the body have pores adequate and open to the particles of the menstruum; and, 3dly, That the cohesion of the parts be out so strong, but that they may be turn asander by the violence of the dissolving particles rushing together.

(27) It is said, 2 salts only will not dissove, when once chrystallized. Tartar as it comes from wine casks, and that made by a vitriolic salt, and one already alkalized, or which will become so when de prived of its ecid. Dr. Lewis in his notes to Neumann's Chemistry, opposes this hypothesis; it is likewise disproved in the Chemical Dictionary, on a supposition that fixed alkalies will effect what is here said, and that the vitriolated tartar can be dissolved.-—See observations respecting Indigo, the ancient purpura, &c., in the section of colour-making.

(28) In this, as in other cases, it is impossible the mind can carry its powers so far into the internal constitutions of substances, not observable by any physical operation, as positively to say, that such things act on each other in such a manner as tending to establish the principles of any operation; therefore in such cases our reasoning is only by inference. But, the further we go in our mental researches, we form more abstract hypotheses; till, at last, our inferences becoming almost fanciful, we talk of invisible operations, and consequently hare recourse to agents of an imaginary formation, to execute them.

This comment may probably seem pre sumptuously trifling with the sentiments of very great men, but whoever peruses chemical works will find how freely each succeeding writer treats his predecessor respecting remote theoretical points. (See the preceding note, and notes 30 and 37 to colour-making where the theory of colouring cloth, &c. is disputed) and the same may be observed respecting experimental processes, in succeeding Writers complaining of inaccuracy or mistatement.

The above, however, must not be understood as invalidating all theory, or setting aside the principles of operations; the consideration of which is, and will be particularly enforced further on: but only as laying a stress on those points that are not deemed subtleties. For notwithstanding, the modern discoveries shew fire, air, water and earth, not to be primary substances, they may here be still held as such, as our practical knowledge must commence from their operations on other substances, deemed secondary ones, or as they enter into their composition: so, in the theory of colours, whatever may be said of the nature of those substances that help to produce them, reasonable positions and practical knowledge can only com mence from that point at which they begin to exhibit their effects. —See note 1 to the retrospect at the end of colour-making.

N. B. In the preliminary suggestions to Fowcroy's Chemistry, the scientific contention above alluded to, among moderns respecting the new theories is displayed. See likewise an abstracted view of the same, prefixed to the chemical compendium in the section of colour-making, and Note 9. to the same.

(29) This chemical or philosophical mode of confidering the matter, was intentionally avoided while speaking of these operations (see the retrospect at the end of colour making) for, in fact, it is of such a nature, that few common coppermen can be supposed to have any conception of it, all they talk of is the said.— See note 31 further on.

(30) In the article of colour making, this is more fully treated. The writer however does  not here affect to point out how to make those distinctions, he only points to the necessity of considering about them, convinced that a Printer of a philosophical turn, might turn what is said to advantage. For though a scheme was absolutely formed for that purpose, yet on reflection, as some might think it would be exhibiting too much, it was laid by, at least for the present: but it may nevertheless be said, that the proper criterion, is regulating the quantity of madder by the quantity of the astringent used; as according to the quantity used in printing any number of pieces, so should be the quantity of madder, weld, &c. in proper proportion.

The above suggestions, it has been said, are equally applicable to ashing and souring; and on the same principles it is advanced by Dr. Home. See notes 3 and 7 to the Retrospect, with the text be longing to note 3, that in souring among bleachers by prosession; the foulness, or rather the absorbent earths left in the cloth after the alkaline process (ashing) so much attracts the acid particles, from having a greater affinity with them than with the water, that thereby, the water at length becomes quite tasteless.

It is added, merely as a remark, this binding or fixing the colour, is reversing the process of preparation; as the liquid there, impregnated with a saline substance, attracts and joins the unctuous substance in the cloth; but here, the salts previously applied to the cloth, attract and join the unctuous colouring substance, suspended in the water.

(31) For they cannot possibly unite with it to the point of saturation from their unctuous quality.

(32) This wonderful property of aifinity in Chemistry is deemed different from the Newtonian grand doctrine of Coelestial attraction; the former, acting on small particles proximate to each other, the latter on large bodies at great distances; and both these properties are distinct, in certain cases, from terrestrial attraction, the property of weight or principle of mechanics.
To speak theoretically of this operation, is applicable to any other, where by means of some preparing substance, a colour is communicated to the cloth, that water nor any other liquid (not corrosive) cannot soften so as to remove, nor the action of the sun reduce to; a calx, or other state, so that it easily goes off ano ther way:

Of the Hypotheses respecting the operation of fixing colour, none are deemed absolutely decisive and satisfactory, the theory however as generally accepted will be here displayed.

It is first of all noted, that the particles of whatever substance is used to colour any article, so that it is durable, are not soluble in either of the usual menstrums (26) whether water, spirits of wine, or alkaline lixivia;  caused by their adhesion to certain gummous and resinous substances, but are liable to be disengaged by what ever has a greater cohesive power, such as allum of tartar, to which the colorific particles of madder, woald, &c. adhere: - But in whatever manner such saline articles act, they fix a colour, that, in general, can be no otherwise obtained; as to those solutions which of themselves form the colour without such preparation, which some certain vegetables do, their effects are attempted to be accounted for, on a supposition that they contain  tenacious, glutinous, or other adhesive quality, with which the cloth, or whatever else it may be, being coloured, can never be removed, when once thoroughly dry: But it is supposed, in every colouring process, by means of boiling, that the colouring particles find admission into the pores of the cloth, which are opened by that operation being previously cleansed by the preparatory salts, and that afterwards contracting by the cold, they retain these particles; and which are further secured by a vitriolated tartar, lining them, as it were, with a crust or what is termed a coagulum, which coagulated matter is generated or produced from the allum, &c. conveyed to the cloth by printing, and the colouring particles they imbibe; this, as said before, is the generally received idea: it is however here observed, that from what is hypothetically advanced, it seems as if heat were absolutely requisite to open the pores for the reception of the colouring particles, but in the instances abovementioned of the juices of some certain vegetables and other subjects, giving a perfectly fast colour without heat, an objection seems to lay against it. (27)

Among other hypotheses concerning the adhesion of colour two or three will be here mentioned, though the above it is clear, must held the first rank, at least-till a better can be adduced.

According to some, the fibres of cloth, silk, &c. are transparent tubes, into which the colouring particles entering are there formed into a kind of cruft, plainly appearing through their transparent encasement; others think these fibres are solid lengthways, but are outwardly full of little pores exceedingly close to each other, into which the colouring particles enter and are there secured; while others think they are entirely solid, or at least no provided with these cellular pores, but that the salts intended to strike the colour corrodes them, sinks into them, and unites with their colouring properties; or else, that the colouring is performed by a coagulation of the colourific matter itself, whatever that quality may be. Thus, it may be observed,ingenious men frame conclusions, formed undoubtedly upon reasonable grounds, which from the confined portion of penetration that we have respecting the internal properties of things, they are glad to embrace sooner than acknowledge an incompetency of knowledge: (28) however in regard to what is advanced above, the grand test is air and sunshine. But as in considering the article of colour-making there may be occasion to speak further on this matter, little more will be said here; what is advanced being deemed sufficient as leading to the operation itself.

As the point of most concern in maddering is the quantity of madder used, it will therefore be spoken of, as well as the criterion that ought to determine it (which consideration is equally applicable to ashing and souring) (29) and is the more desired to be noticed, as it is on this point that Coppermen as well as their Principals, seem so undetermined: some contending for the propriety of allowing plenty of madder, and others being as strenuous for restricting the quantity; and consequently neither can act with that certainty of effect which constitutes the value of any operation.

In the first place (according to the principles, which will be more fully discussed further on) it is not merely by allowing a large quantity of madder that the effect is the more ensured; but the grand point to decide it by, is the knowledge of that affinity or attraction one substance has to another. For here, the question is, how far will the salt or astringent used in printing, act upon, or attract the colouring particles? (30) As to the liquid in the copper being apparently coloured, it is not in consequence of the particles being to the highest degree blended or saturated with it as they are only divided and suspended, and must so remain till some other substance immersed in that liquid attracts and retains them, in consequence of being able to unite with them beyond the power which the liquid has. For, notwith standing some may say, there should be a sufficient or equal impregnation of the water by the madder, whether work be light or dark, yet that can only be under a supposition that the particles fall and rest on the astringent just as they would on any other place, only that they would be there fixed: but the astringent particles are here supposed to have a certain sphere of at traction, acting on every colouring particle that comes within that sphere, and uniting with it accordingly. Therefore the quantity of madder, whether the work be light or heavy, should be according to what is likely to be attracted by the astringents, the rest being conse quently superfluous; which always must be, while the cloth is not all over impregnated witlfthe salts, or the whole capacity of the copper not filled with the cloth: as in this instance, it must be clear there will be more, colouring particles than will come within the sphere ot force of the attraction of the astringent particles.— See note 31 in the section of colourmaking.

It may be observed that in some cases without the use of preparatory salts, this attraction is greatest with the cloth itself; but then the particles are not permanently fixed. —See notes 26 and 41 in the next section. (32)

In order to illustrate what has been just said, suppose ten pieces printed with the same object, either large or small, in deep red; ten more in the second red; and ten more in the palest. Now here, it is not because there appears the same body or miss of colour in one as in the other, that an equal quantity of madder is necessarily alike for each ten pieces, for, if there be barely enough to bring up the palest, there will not be enough for the second, and still less for the darkest: and, inveiting the rule, by having a sufficient quantity to bring up the darkest, there will be more than sufficient for the pale shades, and consequently some madder will be wasted, from the attraction not being so strong in the pale sprigs, through their con taining a smaller number of astringent atoms, as in the darkest sprigs which have considerably more.

The above may be likewise instanced in a piece of pale blotch work, and a piece of dark; as in the dark blotch, there must be a greater number of astringent particles, and consequently their powers of attraction more multiplied than those in the pale blotch, from having a less quantity. In common engraved copper-plate work, this is evident in what is called the spewing of the colour; but it is particularly so, in the tinted work lately introduced; for whether done in black, chocolate, blue or olive, according as the colour is received by the cloth from the lightly tinted parts, it shews difserent shades; hence in these cases, as the colour is not previously thinned, it can only be occasioned by the astringent particles being more dispersed than if the dark places, or in the grounds.

It may be subjoined that there are cases where the copperman may be deceived in sorting the pieces.— See note 21. Indeed it is here aflerted,that the leading principle in copper work is properly sorting them. As to the common wonder of printers, that pieces of the same pattern, colour, &c. do not come up alike, See colour making, under the article of the application of colour by printing.

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REMARKS, &c.

(33) At a certain Ground (the writer thinks Newton's) where madder is by no means spared, the Principal percieving one night a light near the Copperhouse, found, on going thither, the Copperman in the drug-room, adding more madder to what had been weighed out for him; and it appeared, on enquiry, to be only for the purpose of insuring his reputation as ar Copperman, on the principle above mentioned, of thinking he could not use too much. It must be superfluous to add, repeated circumstances of such a nature are of some pecuniary concern, especially where much work is done.

(34) This term of a scald is much used by com mon coppermen, as they build their merit anc! certainty of effect on their judgment about it; and here undoubtedly they are right; though few precisely know why: for in this process, as well as in ashing or souring, there is a certain instant of time when the effect is accomplished, which, chemically speaking, is the point of saturation, (see note 16) and to carry the process on further must be injurious, or, at any rate, superfluous; which point of time is when the noxious or obstructive substance is decomposed or removed; from an assimulation with the alkali or acid then used.

In the fixing of colour, it it when the combination of the salts and colouring particles is formed; for, as in the preparation, if there be any alkali or acid remaining in the copper, after the noxious substance is removed, it either has nothing to act on, or it must act on the cloth. So in maddering, or welding, if the cloth be kept in beyond the point of saturation, or the water be too hot, the red or the yellow will probably be dingy, or otherwise injured as well as the other colours, from the colouring particles acting with other powers, than their merely colouring ones. See note 16.

(35) It is too common in the country, for purposes well known, to use logwood and brazil, and weld likewise in a mode not proper to display; the work of course cannot be very respectable. But even this is better than the frequent flushed up colours, or those pale ones, put in on a chymick principle, chiefly in work which is to be hurried up to town (see note
10 in the Retrospect at the end ot Colour-making) but these practices, it is hoped, for the credit of the business, are falling into decay, as more fully observed further on. As to branning but a few pieces at a time, it certainly is an im provement; as among the modes practised in the country (at least more so than about town) goods are frequently branned so much white (and bran liquor may be converted into sours in a certain time) as to be deemed sufficiently passable: and indeed in some close covering kinds of work, the goods may be so much branned, as to need little if any grassing: but then (as just said) such work will always be distinguished from that which has a good white. See note 37.

(36) A natural consequence of a heap of vegetable matters, as well as animal, laying together, according to their humidity, and their acid or alkaline qualities, is a heat arising in the middle, which by degrees spreading more and more, will at length putrefy or rot them; this intestine motion disintangling the acid or alkaline quality from the earthy and oily parts, that till then retained in them. Some thing like this happens in soaking white goods (as mentioned before) and it may here be added, that white goods as well as when finished, should not be piled up too damp, nor in too damp a place; and at any rate they should be examined at times, or stains at least will be the consequence. It may even be said, that the injury white goods may thus receive (as what are called mildews, are the first stages of putrefaction, or rottenness) may affect the preparation and printing.

The modern anti-phlogistic or pneumatic theory of Chemistry, including Dr. Priestly's celebrated discoveries, have thrown some light on the subject of putrefaction and its preceding stages; though still it is far from being satisfactorily developed.— See the subject discussed by Fourcroy Vol. 3 —See likewise Higgins on the acetous acid, air, &c.

(37) Speaking of what may come down in a stream, the following circumstance which happened some time ago i6 quite in point. As a number of pieces were rincing, printed in chymick Colours, to the surprise of the rincer, he found the colours changed. The cause on examination appeared to be from a quantity of ash and other matters from the clearing of the coppers, coming down with the stream from an adjacent dye-house.

As the purity or certain quality of water is of great consequence, whether for Colour-making, Copper-work, or Fielding, it is just intimated, that its gravity being generally in proportion to its purity, the common hydrometer will discover it.—In Berg man's works, his experiments on waters, in order to remove impurities, and render waters fit for various purposes, are truly of importance to Callico-Printers, Dyers, and all who use considerable quantities of it; and in this case (as well as in others) if it were not from the sear of doing a particular injury, it could here be shewn, from experiments actually made by the writer himself, which Printing-grounds in the vicinity of London, are more or less fortunate in that respect.* (* Among the works referred to, may be found the modes of doing it. If this is thought too exposng, let those nuho are not fortunate in this case, endeavour to remove the complaint; as the methods are there shown.) in fact, it is matter of wonder this has not been more an object of enquiry among Callico-Printers and others, where the goodness of water is of some concern; especially as little trouble and expence are required to render impure waters m certain cases, and in certain quantities otherwise.

Perhaps the singular effects (as has been observed) of waters in India are owing to high degrees of purity, through a friendly interserence of nature; and, as applicable to the subject, it is mentioned as no secret, that at a capital Printing-ground near town, the waters of a very copious spring, which for a time had been used for Fielding, were at last, by accident, found not to be so efficacious as the water that was rejected.— A Printing-ground could be even pointed out, where the waters are of a saline quality, and the ill effects even acknowledged.

To philosophical men it is just hinted, that probably the modern discoveries respecting air, might be turned to some advantage in nice operations, if the wondersul properties of water impregnated with fixed air, be considered. But to expatiate further on these points Would be entering into too large a field, the reader is therefore referred to the works mentioned over-leas, or advertised at the end, for that information which would be perhaps aukwardly exhibited here if compressed.* (* Some particulars will be found preceding the Compendium of Chemistry.) These remarks how ever, must shew the usefulness of philosophy, and the advantage the arts acquire where its aid is ob tained: and hence the superiority of many operations on the Continent, where such a combination is encouraged: indeed, the merely mechanic arts cannot aspire to improvement without it, nor proceed with certainty, even in common operations, from the very obvious reason of its implying the necessity of thinking as well as acting.

These observations likewise include the great necessity of regarding situation, particularly in forming Bleaching or Printing Grounds; for, as partly observed already, it is morally impossible to command brilliancy of operative effect, if (besides what is above intimated) they lay under disadvantages arising from  dense vapours, or gross suliginous matters, variously impregnating the contiguous part of the atmosphere. — See something to this effect notes 6 and
7.— In short, without pure Crater, and pure drugs, operation is uncertain, and the effects dis creditable.

N. B. Those who desire information on these heads, and others equally important, are here desired to consult Bergman's Chemical Essays on Air, Water, &c. Priestly on Air; Fourcroy's compendious statement of General Theories and Experiments relating to them; Cronstedt's Mineralogy; and Higgins on acetous Acid, Air, &c.

It is however here said, that allum, saccharine acid, lime, galls, fixed alkali, &c. are the agents for detecting impurities in waters; it is likewise  said, however strange it seem, that vats and other certain receptacles of waters should not often be cleared from the green matter that gathers on the bottom andsides. And this observation may be perhaps applied to ditchts, so the sedgy matter is not floating, nor liable to be taken up with the gittern, as it is said to imbibe the phlogiston from the air.— See Priestly particularly.

It may not be quite foreign to this subject to add, that Dr. Priestly says the air which he procured from a Callico Printing-ground (most probably the; Printing-shop) was the most offensive of all the specimens that he procured from different manufactories. —See something to this purpose in Percival's Essays on the air of Manchester.
In maddering, 3 certain distinctions should be made, the the Copperman as just said, should know how to make more according to the lightness or heaviness of the work. The three alluded to, are dark grounds, close covering work, and light grounds; but in this distinction it is impossible to ascertain here what quantity of madder to use, as a copperman who has attended the previous processes, if the cloth has been well ma naged in other respects (faying nothing about what has been just discussed) will bring up work with nearly half the quantity that some others will; for too many if left to themselves, rarely deal out madder with a sparing hand, (33) However, it may possibly be said if it be  of a good spending sort, heavy work may require seven or eight pounds to a piece, and for light work from four to fix. But all this, as observed respecting ajhing, souring, &c. must depend on discretion or other circumstances; for written documents cannot provide for every course of work.

As to the general mode of process, according to the size of the copper, the course of work, or dimensions of the goods, tie up more or less, rarely more than ten of light work, but less of heavy: bring the copper to a scald (34) in about an hour and a half, and keep it in that slate till the colour has sufficiently risen. With light goods this first scald will answer for sumaching.

After this scalding, have them planked or washed, then enter them in fresh madder, and bring the water to a boil in about an hour; but great caution must be taken that the colour is raised before the work is taken from the copper: and it may be observed that too much boiling will extract a brown from the madder itself, which of course must debase the work.

After this second process, have them washed, then bran them, and after being well walhed in the stream, strike them off in the barrow, and have them snitchelled up for the purpose of draining previous to being laid on the parks.

Branning is supposed to smooth the surface of the colour, by removing intervening particles that might render it otherwise. — See note 6 in the retrospect. (35)

After the process of branning, the goods should not be suffered to lay long in the heap, if they be, they must suffer from the fermentation that will naturally arise. (36) As to the processes of sumaching, woalding, &c. they being similar in respect to striking the colour, excepting that some articles give out their tinging qualities very easily, it would be almost a repstition to speak of them. In rincing and streaming of pencilled and chemical colours, the chief consideration is throwing them In quickly and keeping them in motion; and especially in streaming, that the pieces be kept as clear of each other as possible till the work be pretty well cleared.

Cleanliness having been repeatedly mentioned, as a grand point of copper work, the copper man here is- particularly advised to it in the first in stance of supplying the copper with water, for if taken from some streams, various matters may be brought down that may do considerable injury. And in ground reservoirs or ponds, it should be noted that there be no influx of filth of any kind, and especially that they be not near ponds or other places where ashed or soured goods are rinced, for fear such soul waters find their way to them. (37)