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.
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.

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