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ences were not removed. Various attempts were made to effect this, and since it has been effected, several persons have put in their claims as inventors of so useful an improvement. Mr Higgins of Dublin, and M. Berthollet, had both combined the oxymuriatic acid with potash, so early as the year 1788. The knowledge of this having been done by the latter, and of the fact that the acid was thus deprived of its offensive smell, induced the bleachers at Javelle, in France, to add a solution of caustic potash. Hence the oxymuriatic acid, combined with an alkali, is usually known by the name of the Javelle liquor.

No further improvements seem to have taken place in the combination of this acid with any other substance than the alkalies, until the year 1798, when Mr Charles Tennant of Glasgow, by a well-conducted series of experiments, showed that it was capable of being united with what are called the alkaline earths, such as barytes, strontitis, and lime. This discovery is of great importance, and may indeed be said to make a new era in the history of bleaching, as by means of so common and cheap a substance as lime, the full effect of the oxymuriatic acid is communicated to the cloth, and great saving is effected by its substitution in place of an alkali.*

In the bleaching of flax and hemp, Berthollet made some experiments, which succeeded in giving to their fibres the whiteness and softness of cotton. He subjected them to the action of chlorine, which bleached them effectually; but, at the same time, it injured their fibre, and although a thread was produced of considerable tenacity, yet the shortness of the staple was such as to render the spinning a troublesome operation. It was found that this process had the remarkable property of reducing the finest flax and the coarsest hemp alike to one uniform fineness of fibre and colour, and that even the refuse from rope-walks might thus be made into a substance valuable in the arts.†

* See Edinburgh Encyclopedia, article-Bleaching.
Nicholson's Journal, vol. vi.

EIGHTH WEEK-THURSDAY.

CLOTHING.-THE ART OF DYEING ITS ORIGIN AND ANCIENT HISTORY.

THE perception of colour seems to be accompanied with immediate pleasure; and though the effect is probably heightened by association, it is so instantaneously produced, that we are only conscious of the pleasing emotion, and seldom think of searching beyond it for the source of our delight. Long before we are capable of analyzing our feelings, the eye is caught with the brilliancy of colour and the splendour of illumination. Some even of the lower animals seem not to be altogether insensible to the beauties of rich and variegated tints; and man, in his rudest state, has always regarded colour as a principal constituent of ornament. Nor is it only in the judgment of the infant or the savage, that colours rank high among the elements of beauty. In the most refined periods of human society, they retain their attraction, and although, to a cultivated taste, the pleasure depends on blending and harmonizing rather than on brilliancy and strong contrasts, which seem to afford the first enjoyment, this refinement rather increases than diminishes their influence.

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Among the several kinds of beauty," says Addison, "the eye takes most delight in colours. We no where meet with a more glorious or pleasing show in nature, than what appears in the heavens at the rising and setting of the sun, which is wholly made up of those different stains of light, that show themselves in clouds of a different situation. For this reason we find the poets, who are always addressing themselves to the imagination, borrowing more of their epithets from colour, than from any other topic."

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To this delight, which we derive from the perception * Spectator, No. 412.

of colours, must be referred the origin of dyeing. The savage would naturally wish to appropriate and to have constantly in view what afforded him so much pleasure. Vanity might induce him to adopt some coloured substance as a personal ornament, or to employ it in giving beauty to the furniture of his rude dwelling. His fondness for brilliancy or variety would prompt him to make trial of different substances; and though many of his experiments, as they would be guided by no fixed principle, might fail, some of them would succeed, and thus gradually lead to the discovery of useful dyes. Perseverance would supply the place of knowledge, and accident would sometimes disclose, what experiment might never have found out.

These remarks may even be applied to the art after it had attained a more advanced state, and when it might have been expected that science would have lent greater assistance to a subject, so susceptible of improvement by inductive investigation. It has often been remarked, however, and not without reason, that almost every important discovery in the arts has been the offspring of accident, and that science has done little more than suggest hints for improving what chance may have offered to human observation.

That the art of dyeing originated before the period of authentic history, there can be no doubt. I have already observed, that it was known so far back as the time of Moses, and indeed two hundred years before his day, during the youth of Joseph ; and it is worthy of remark, that, even in those early days, the colours which were made use of indicated a considerable progress in the art. In India, too, the process was certainly known at a very remote period. The natural fertility of the soil of that country, and the great variety of materials which it affords for dyeing, were extremely favourable to its improvement. But religious prejudices, and the unalterable division into castes, soon imposed restraints on ingenuity. The arts became stationary; and it would

seem that the knowledge of dyeing cotton was as far advanced when Alexander the Great invaded the country, as it is at present. Even at this day the Indian processes are so complicated, tedious, and imperfect, that in any other country they would be impracticable, like their mode of weaving, on account of the price of labour. European industry has far surpassed them in correctness of design, variety of shade, and facility of execution; and if, in the liveliness of two or three colours we are inferior to them, this is solely to be ascribed to the superior quality of some of their dyes, or perhaps to the length and multiplicity of their operations.*

The Egyptians do not seem to have made any important additions to the art of dyeing; and, indeed, little could be expected from the genius or industry of a people, who were strictly prohibited, by the principles of their religion, from changing even their most indifferent customs. It appears, however, from Pliny, that they were acquainted with a mode of dyeing, very much resembling our modern calico-printing. He mentions, that the Egyptians began by painting on white cloth, with certain drugs, which, in themselves, possessed no colour, but had the property of attracting or absorbing colouring matters; that these cloths were afterwards immersed in a heated dyeing liquor, of a uniform colour; and yet, when removed from it, soon after, that they were found to be stained with indelible colours, differing from one another, according to the nature of the drugs, which had been applied to different parts of the stuff.+

The Tyrian purple has already been mentioned, and I need only add, that the art of producing it was for centuries lost, in consequence of the restrictions which imperial pride placed on the use of it. The Roman emperors appropriated this colour entirely to themselves, and denounced the punishment of death against those who should presume to wear it. This tyrannical restric

* See Berthollet.

† Pliny, book xxxv. chap. 2.

tion so limited the dyeing of the purple, that, with the imperial throne, the process itself was lost. In the twelfth century, neither the shell-fish, which furnished the dye, nor the methods which the ancients employed to communicate to cloths the rich and beautiful purple which it afforded, were at all known. At a later period, however, the material of the dye has been discovered. Cole, in the year 1686, found some shell-fish on the coast of England, which yielded it. Reaumur detected it in the whilks which he obtained on the coast of Poitou, and Dumahel in a shell-fish produced in great abundance on the coast of Provence. It has been discovered, also, in South America, in the Antilles, and on various shores of the Mediterranean; and there is reason to believe that it exists in as great plenty now, as it did in the days of the ancients. If this dye, therefore, is not used in our day, it is because we are acquainted with more beautiful, as well as less expensive colours for the art.

The Greeks and Romans made but little progress in the art of dyeing. Public opinion, among them, placed the fine and the useful arts at an immense distance from each other; for, while the highest honour was connected with the former, the latter were degraded among the dishonourable and servile employments. This prejudice, which well accounts for the small improvement made by these otherwise active and ingenious nations, in many of those employments that have made such rapid advancement in our own days, forms a remarkable contrast between ancient and modern times. A philosopher of our day does not affect the distant and austere habits of the sages of antiquity: He mixes freely in society, and does not disdain to derive information from whatever nature or art may offer to his observation. The instruction he has received from the artist, has been amply repaid by the light which science has shed on the arts, and the explanations it has afforded of their various processes.

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* Edinburgh Encyclopedia.

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