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)
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