The Dyer's Guide. Chapter I. Introductory. On vegetable and animal substances.

The Dyer's Guide
Being a Compendium of the Art of Dyeing
Linen, Cotton, Silk, Wool, Muslin, Dresses, Furniture, &c. &c.

With The Method of
Scouring Wool, Bleaching Cotton, &c.
Directions for Ungumming Silk, And For Whitening And Sulphuring Silk And Wool.
And Also
An Inttroductory Epitome of The Leading Facts in Chemistry, As Connected With The Art of Dyeing.

By Thomas Packer,
Dyer and Practical Chemist.

"Cet arte est un des plus utiles et des plus merveilleux qu'on connoisse."
- Chaptal.

"There is no art which depends so much on chemistry as dyeing."
- Garnett.

Second Edition,
Corrected and Materially Improved.

Printed for Sherwood, Gilbert, And Piper,

In order more correctly to understand the theory and practice of dyeing, it is essential that the pupil should become acquainted with the nature of the substances upon which and with which he must necessarily operate. We shall not enter into the theories of light and of colours, as propounded by Sir Isaac Newton, as well as many illustrious chemists, who have already done so much for the art of dyeing, but shall simply refer to such writers as Ure, Bancroft, Berthollet, Brande, &c. from whom may be learnt what is of most importance to be known concerning this curious subject.

We may just add, however, in regard to light, that Sir Isaac Newton proved it consists of rays differing from each other in their relative refrangibilities. By causing light to pass through a hole in a window-shutter into a darkened room, and receiving that light on a glass prism, the rays, in passing through the prism, not only became refracted, that is, thrown out, of the rectilinear direction, but also separated into seven distinct colours, namely, red, orange, yellow, green, blue, indigo, and violet. The red being the least refracted and violet the most. If these prismatic, or primary colours, as they are usually called, be divided into 360 equal parts, the red rays will occupy 45 of these parts, the orange 27, the yellow 48, the green 60, the blue 60, the indigo 40, and the violet 80, and, what is very remarkable, these colours, when mixed in the proportions here set down, produce white. This may be readily proved by mixing seven powders of the colours and quantity mentioned, or by painting a wheel with the same proportions of the different colours and making it revolve rapidly. But it should be noted, that, in either case, the white will not be so pure and delicate, as that produced by the mixture of the rays of light. Upon these phenomena is founded the Newtonian theory of colours. Thus green bodies reflect the green rays and absorb the others. All the rays are reflected by white bodies, and absorbed by those which are black.

It is, notwithstanding, highly necessary that the learner should know that portion of modern chemistry which will lead him to the best secrets of his art, and hence assure him of that which was only before conjecture. And it cannot be sufficiently impressed upon him, that if our theory be not true, we work from wrong data; we may, it is true, approach the truth; be right in some things and wrong in others, and our uncertainty and mistakes will be accordingly; yet the most complete dyer must be he, who with extensive practice combines a knowledge of the true principles of his art, to which modern chemistry is, doubtless, the key.

It is scarcely necessary to insist further on the importance of a knowledge of the constituent parts of vegetable and animal bodies, as well as those inorganic substances with which chemistry has so largely to deal; but it will be seen, in the course of our subsequent observations, what difficulty there is in dyeing cotton of a red colour, similar to that produced by cochineal on wool; how, in dyeing cotton yarn an Adrianople red, the intestinal liquor of the sheep, and the dung and the blood of the same animal are used, and have been found so important by the dyers of Asia; hence the colour is called the Adrianople or Turkey red.

It is found by experience, and particularly in hot climates, that substances containing ammonia (volatile alkali) quite developed, have the property of raising and rendering more intense the red colours. It has been found, too, that the bones of animals retain the colour of madder very strongly, when they have been given that colouring material; and the vivacity of the colour has been attributed in such cases, it is presumed with truth, to the ammonia which the bones contain.

There are, therefore, in regard to vegetables in particular, some things, the nature and properties of which it is absolutely necessary that the dyer should understand: for want of a knowledge of one of them, it is a fact that losses are very often sustained to a serious amount. It may seem surprising, but the author has not seen in any writer on dyeing or chemistry, a proper method of working the pastil or woad vat; nor how to renew and work it down, again and again, with an assurance that it will be neither decomposed nor spoiled; and which, for want of a proper knowledge, it has often been. We shall therefore endeavour to give some directions by which those fatal and expensive disasters may be avoided.

Although, at first sight, it seems easy to distinguish the three kingdoms of nature from each other, yet there is such an imperceptible transition from one to the other, that it will be difficult to give such a definition as shall embrace all the individuals of each, and, at the same time, exclude those of the other kingdoms. On examination, indeed, we do find that there is in fact no natural distinction of this kind; and that there is scarcely a function common to vegetables and minerals which some of the animal tribe do not enjoy, and vice versa. Yet it must, however, be noted, that most animals have the power of voluntary loco-motion, and are thus rendered peculiarly different from all other bodies which we find upon or in the earth.

The substances constituting vegetable differ from those constituting mineral bodies, in their being of a more complex kind; and though vegetables are extremely susceptible of decomposition in various ways, not one can be, by any art, synthetically produced. Yet, although what are called by chemists the proximate constituents of vegetables are numerous, such are water, starch, sugar, gum, gluten, wax, oil, camphor, resins, colouring matter, extractive matter, several acids, &c. &c. all of which are capable of being decomposed, the ultimate constituents of vegetables are very few; the chief are carbon, hydrogen, and oxygen; some afford nitrogen; in some are traces of sulphur, potassa, lime, soda, magnesia, silica, &c.; in nearly all vegetables are traces of iron; in many manganese.

As the proximate principles of vegetables are chiefly carbon, hydrogen, and oxygen, it will be useful to inquire how vegetables obtain these materials. Water, which is composed of hydrogen and oxygen, is a ready source whence both its constituents may be obtained; and it is concluded that it is decomposed in the glands of vegetables, assisted by solar light, and becomes fixed in them in the state of oil, extract, mucilage, &c. The greatest part, however, of vegetables consists of carbon, or, to make ourselves more intelligible, pure charcoal; the carbon, notwithstanding its solidity in the shape of charcoal, most readily combines with oxygen, and hence it forms, as carbonic acid, a small portion of atmospheric air, from which source the carbon of plants is in part at least derived. Another source from which plants derive their carbon is the earth, and decaying vegetable matters; the dung of animals supplies also some of the constituents of vegetables. Indeed, in the application of dung and other matters, so as to promote the healthy and vigorous growth of vegetables, does the science of agriculture chiefly consist. It appears, however, that nourishment is received principally, if not entirely, by plants in a liquid or gaseous form. It should be noticed too, that few, if any, healthy vegetables will grow any where except in light, a powerful stimulant at all times, not only to plants but to animals; such are its effects, that many dyes in cloth are materially altered, nay, sometimes destroyed by it.

Animal substances thus diflfer from vegetables: they afford a considerable quantity of ammonia, (which is, it is now known, a compound body consisting of hydrogen and nitrogen), and very fetid products, either by the action of fire, or by the putrid fermentation. They also putrify more readily and speedily than vegetables, and give out a very disagreeable smell. They also contain a con- siderable quantity of nitrogen, the presence of which constitutes the most striking peculiarity of animal compared with vegetable bodies; but as some vegetables contain nitrogen, so there are certain animal principles into the composition of which nitrogen does not enter. The chief ultimate principles then of animal matter are carbon, hydrogen, oxygen, and nitrogen; but phosphorus and sulphur are also often contained in it. Lime also exists in animal bones and shells in considerable quantity, usually, however, in combination with the phosphoric and the carbonic acid. The chief proximate principles of animal matter are blood, albumen, gelatine, colouring matter, milk, bile, lymph, urine, skin, muscle, horn, hair, fat, cerebral substance, shell, and bone, &c.

The differences between vegetable and animal bodies appear to depend upon animal matter containing nitrogen in much greater abundance than it is found in vegetables; and hence the decomposition of animal matter by destructive distillation is characterized by the presence of ammonia, which is formed by the union of the hydrogen with the nitrogen; and it is sometimes so abundantly generated as to be the leading product: thus when horns, hoofs, or bones are distilled by themselves, a quantity of solid carbonate of ammonia and of the same substance combined with a foetid oil, and dissolved in water, are obtained. Hence the preparations called salt and spirit of hartshorn and animal oil.

The principal animal fluids are blood, milk, and bile. The blood, soon after it is taken from the living animal, separates into two parts, one called the crassamentum, which is red, and the other serum, which is a fluid, and of a pale straw-colour; the crassamentum is a more firm and consistent mass than the serum, by which it is usually, when cool, surrounded. Milk consists of serum or whey, butter, which while floating on the milk is called cream, and curd or cheese, which has the leading properties of coagulated albumen. The bile, as has been before stated, is a saponaceous fluid consisting chiefly of albumen, soda, a bitter resin, water, and some other saline matter. Fat, in the dead animal, is merely animal oil in a concrete or hardened state.

The principal animal solids besides bone, are albumen, gelatine, andjibrin. These substances, in certain states of concretion and combination, form all the solids of animals, and are separable from each other by easy analysis.

By whatever means we deprive animal substances of their nitrogen, we reduce them to a state similar to that of vegetables. The muscular fibre, or flesh as it is usually called, when excluded from the air, but particularly if in contact with water, parts with its nitrogen, and is converted into a substance resembling spermaceti, which in its analysis agrees with vegetable expressed oil.

When vegetables and animals are deprived of life, their various parts, and especially their fluids, sooner or later, spontaneously assume processes which terminate in their total decomposition. The earlier stages which lead to their decomposition are iexvaeA fermentation. Of this there are three kinds; the first, or vinous fermentation, takes place in vegetable juices which contain a considerable quantity of sugar, such are the juices of the grape forming wine, of the apple forming cyder, &c. In this fermentation a considerable quantity of carbonic acid gas is disengaged; this gas is very destructive to animal life, no one can live for a minute in it. If, after the vinous fermentation is completed, the liquor be exposed for some time to atmospheric air, another fermentation takes place, oxygen is absorbed, and the liquor becomes vinegar, hence called the acetous fermentation. The putrid fermentation generally takes place in animal bodies very soon after death, so that neither of the other processes, certainly not the vinous, the acetous rarely, becomes a condition of animal matter.

The chief product of the vinous fermentation is an intoxicating, colourless, volatile, and highly inflammable liquor called alcohol; in common language rectified spirits of wine. It may be obtained by distillation from wine, cyder, perry, brandy, &c. &c.; and from whatever liquor it be obtained, when freed from extraneous matter, it is in every case the same. Alcohol consists of hydrogen, carbon, and oxygen. Its usual specific gravity is 825, water being 1000.

After vegetables have passed through these fermenting processes, the decomposition continuing, unless checked by extraneous means, the remainder of their constituents become separated, many of them being volatilized in the form of gas, and nothing remains but a black or brown residuum called mould, consisting of carbon, some salts, a little oil, and extractive matter.

In the decomposition of animal substances, we perceive the union of hydrogen and nitrogen forming ammonia; the combination of carbon with oxygen produces carbonic acid; and nitric acid arises from the union of oxygen and nitrogen. A quantity of hydrogen is also extricated in the form of gas, carrying off with it sulphur and phosphorus, which produce together the disagreeable smell arising from animal putrefaction. Nothing now remains but a portion of carbon mixed with phosphate of soda and phosphate of lime.

Hence we see that, by the processes of fermentation, complex bodies are converted into more simple substances, and that nature restores, in the new combinations, the principles which she had borrowed from the atmosphere for the formation of both animals and vegetables; and that she accomplishes a perpetual circle of ever-changing being, at once demonstrating the fecundity of her resources, and the grandeur and simplicity of her operations.

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