from its scarcity the dye was always very costly, and in consequence reserved for dyeing the hangings of temples, or the robes of priests and kings. The hue of the best resembled that of coagulated blood,* but means were resorted to by which various tints were obtained, and the cloth was often stained first of one shade, and then dipped into a deeper coloured liquid to give it a fuller and richer gloss. "Wool which had received this double Tyrian dye (dia bapha), was so very costly that, in the reign of Augustus, it sold for about 367. the pound. But lest this should not be sufficient to exclude all from the use of it but those invested with the very highest dignities of the State, laws were made inflicting severe penalties, and even death, upon all who should presume to wear it under the dignity of an emperor. The art of dyeing this colour came at length to be practised by a few individuals only, appointed by the emperors, and having been interrupted about the beginning of the twelfth century all knowledge of it died away, and during several ages this celebrated dye was considered and lamented as an irrecoverable loss.' But though the art was lost to the places which gave it birth, and which it had enriched, in our own island it was practised at the very time when the learned lamented it as extinct, and where it seems to have been known from time immemorial, being probably rather an art of native growth than the importation of a foreign commerce; and, perhaps, it were no errant conjecture to suppose that it might be the colour "By which our naked ancestors obscured Their hardy limbs, inwrought with mystic forms, The Venerable Bede, who wrote in the eighth century, mentions the art as a known thing in his days, and he was familiar with the beauty and permanency of the colour.† The "In the Greek language, purple and porphyry are the same word; and as the colours of nature are invariable, we may learn that a dark deep red was the Tyrian dye which stained the purple of the ancients."-GIBBON, Dec. and Fall, ix. 57. The passage is quoted by Dr. Lister in a paper on the subject in the Phil. Trans. for 1693, p. 645, and is as follows:-" Variis conchyliorum generibus exceptis: in quibus sunt et musculæ, quibus inclusam sæpe margaritam omnis quidem coloris optimam inveniunt; id est, et rubicundi et purpurei, et hyacinthi et prasini, sed maxime candidi. Sunt et cochleæ satis superque abundantes, quibus tinctura coccinei coloris conficitur. Cujus rubor pulcherrimus nullo unquam solis ardore, nulla valet pluviarum injuria pallescere; sed quo vetustior, eo solet esse venustior.' --Hist. Eccles. Gent. Ang. lib. i. c. 1. a same fact is mentioned by Richard of Cirencester,* and also in a translation of Higden's Polichronicon made in the year 1387. The language used by these authors implies that the art was familiarly known and followed, but, from its limited utility, it seems gradually to have gone into disuse, until at length a few families only preserved the custom of the olden time, and handed it down to their posterity as a family secret. In 1684, Mr. William Cole, of Bristol, having been informed that "there was a certain person living by the sea-side in some port or creek in Ireland, who made considerable gain by marking with a delicate durable crimson colour fine linen of ladies, gent., &c.,"—a colour which was "taken out of a shell-fish," -was induced to institute some experiments on the common shell-fish of our coast, and after various trials he succeeded in finding the object of his search in the Purpura lapillus. After breaking the shell carefully, "there will appear," he says, "a white vein lying transversely in a little furrow or cleft, next to the head of the fish," description you will remark in exact accordance with Aristotle's, and in this vein the white viscid liquor is found with which the linen is to be marked. Jussieu made similar experiments, in 1709, on the shores of France; which, in the year following, were repeated by the celebrated Reaumur, who has given a very interesting account of his inquiry in the Histoire de l'Académie des Sciences Naturelles for 1711. Reaumur also accidentally discovered that the egg-vesicles of the Purpura afforded the dye in greater abundance, and with less trouble to the experimenter, than the fish itself. These vesicles, which are of a vase-like shape, and about the size of grains of wheat, hang in clusters under shelving rocks; and although Reaumur could never satisfy himself whether they were the eggs of the Purpura, or the eggs of some fish on which it fed, their nature is no longer uncertain. The experiments of these naturalists have been subsequently repeated by others, so that the nature of the dye is now well-known. It has been ascertained, too, that * Desc. of Britain, 28.. "Ther beth_ofte take delphyns and see calves and balenys gret fishes as hit were a whalles kynde and dyverse maner shelle fishe. among the shelle fishe beth muscles that hath among hem mariory perles of all maners coloure and hew rody and reed of purple and of blew and specialy most of white. ther is also of shel that we dieth with fyne reede. the rednesse ther of is wondre fayre and stable and steyneth never with colde ne with hete ne with drie but ever the eldere the hew is fayrere."-Book i. ch. 38 of "Bretayn." For this extract I am indebted to the Rev. Jos. Stevenson, so well known for the extent of his acquaintance with our early historical literature. Phil. Trans. xv. 1280. the Chinese make use of a similar dye; and in the new world, according to Don Antonio de Ulloa, the inhabitants of the provinces Guayaquil and Guatimala have, time out of memory, procured it from certain conchs or sea-snails about the size of small nuts, or a little larger. The colour is in great estimation among them from its scarcity; "and, indeed, there is hardly any thing dyed with it but laces, borders, fringes, and such like works."* The scarcity of the colouring liquid, and the discovery of cochineal, have rendered the Tyrian purple valueless as an object of commerce. Dr. Bancroft thinks it might still be rendered beneficial in staining or printing fine muslins, for which little colouring matter is required; and Mr. Montagu strongly recommends it for the purpose of marking linen, since the colour grows brighter by washing, and cannot, so far as is known, be removed by any chemical agent. It in fact excels all animal colours in durability and unchangeableness, as well as in the simplicity of its application. "It is strictly and preeminently," says Dr. Bancroft, "entitled to the distinction of a substantive colour, as it may be permanently fixed, even upon linen and cotton, by the most simple application, and without any preparation or admixture whatever; and it is admirable for the singular constancy with which it proceeds through the series of intermediate colours (according to their prismatic arrangement), until it has permanently fixed itself, and attained that purple tint which the Author of nature, for some unknown purpose, has fitted it to display; and all this in spite, if I may so express myself, of many powerful chemical agents, whose utmost influence extends only to retard, for a few hours, the ultimate accomplishment of this its destiny." The changes alluded to in this passage are these: the fluid, when in the living animal and on its first extraction, is cream-coloured, or, as Reaumur has happily said, it has the appearance and consistence of well-formed pus. When applied to the cloth, it appears at first of a pleasant light green colour, and being exposed to the light the green gradually increases in intensity, from a deep green to a full sea-green; then it passes to a watchet blue, which soon acquires a tint of red, and at *Gent. Mag. xxiii. 461.-"There is one further particular relating to this shell-fish which is very remarkable, and that is, that its weight and the colour of its juices are different at different hours of the day; and that there is a certain hour when the weight of the fish is the greatest, and the colour in the highest perfection; and this is so well known to the dealers in this commodity at Nicoya, that the hour when the fish is to be weighed and delivered is always particularly mentioned in the bargains and contracts." + On Permanent Colours, i. 158. * last waxes to a very deep purple-red. The light and air can do no more; but if the cloth is now washed in scalding water and soap, it comes out from the lather of a fair bright crimson, which no subsequent process can change or lessen. While the cloth, wet with the dye, lies in the sun it exhales a strong foetid smell, as if garlic and assafoetida were mixed together, nor am I aware how this was got rid of in ancient practice, for I presume it is a quality inherent in the secretion of all purpuriferous fish, notwithstanding that Pliny's mode of expression would seem to imply that the "stinking savour " was peculiar to the less esteemed kinds. When exposed to the light, the colour runs through all the above changes in a few minutes; and if the light or heat be very strong, they succeed one another so quickly that the intermediate hues cannot be observed. By moderating the light the process is prolonged, and the whole series may be noted with accuracy; and if the light is excluded entirely, no change whatever takes place, but the dye remains of its native pale yellow or cream colour, and will so remain for years, until the admission of light revives its dormant energies. Dr. Bancroft kept pieces of linen stained with the liquor for nine years between the leaves of a book without any visible change, but which, at the expiration of that period, were influenced by light in the same way as recently-stained pieces, and as readily acquired the glowing purple. There are two ways of explaining this curious series of changes. We may suppose, with Berthollet, that they are owing to the base gaining additional doses of oxygen from the atmosphere and varying its hue accordingly; but, though this explanation has been received by many good chemists, Dr. Bancroft appears to have satisfactorily proved that the very opposite is the true theory;-the base parting with a redundant portion of oxygen "naturally combined for some unknown purpose in the liquor of these shell-fish ; and in that particular state which will not admit of its being separated without the application and assistance of light; as is also the case of horned silver, rendered purple by the sun's rays; of vegetables, rendered green by the same cause, after they had become white by growing in darkness; of peaches, purple grapes, and other fruit, which never acquire their proper colours by any degrees of heat, but always remain white or green, if shaded and secluded from the contact of the sun's rays."+ Cole in Phil. Trans. xv. 1280-1. + On Perm. Colours, i. 145.-This work contains the fullest and best account of the Tyrian-purples of any I have had the opportunity of reading. Another article highly valued in the arts, the China or Indian-ink, is very generally believed to be manufactured fron the black liquor excreted by certain cephalopod mollusca, more especially, according to Bosc, from the Sepia rugosa: but the fact, however confidently some have affirmed it, cannot be said to be determined in the affirmative at least.* The colour called sepia is, however, composed almost solely of the cuttle's secretion; and, from various passages in the Latin writers, we learn that the same was used in their days in lieu of writing-ink. In Italy an ink is still prepared from the liquor in question, which Cuvier says differs from the genuine China-ink only in being a little less black. The liquor-and that of the Octopus and Loligo, is preferable to that of the Sepia-is expressed from the cellular tissue of its bladder in the state of a thickish bouillie, which diffuses itself readily in water and blackens a very considerable quantity. Received into a vessel, it dries in a few hours, and detaches itself in scales, similar to those of China-ink. With this preparation Cuvier drew the beautiful designs which illustrate his memoir; and he thinks it would be easy to originate a little branch of industry on whatever coasts these cephalopods abound. I suspect not; for, according to the experiments of Dr. Bancroft, the ink of the cuttles, although durable enough, is otherwise objectionable; the strokes of the pen are not uniformly black, from the carbonaceous particles not being equally dispersed through the fluid, which, moreover, is liable to putrefy, and in its natural state could not be long preserved for the purposes of ink, unless the carbonaceous matter were separated from the animal mucilage, and mixed with a solution of gum arabic.‡ The mother-of-pearl, applied in so many ways, as you are well aware, to ornamental works, is got from the pearl-oyster and from the large bivalve shells allied to it, and native of the same seas. Cameos are cut on some thick shells with a nacred inner layer. With the powdered bone or shell of the Sepia, silversmiths make excellent moulds for casting articles of small work, such as spoons, forks, and rings; and statuaries and china-menders mix the glairy fluid of the garden-snail Besides those already referred to, the curious reader may consult Aristotle, Hist. Animal., lib. v. cap. 13; Edinb. Encyclop. viii. Art. Dyeing ; Thomson's Hist. Roy. Soc. 67, &c.; Beckman's Hist. of Inventions, vols. i. and ii.; Pennant's Brit. Zool. iv.; Montagu's Test. Brit. Supp. 105, 108, 120, &c. Aldrovandus has gathered together everything ever said on the subject previous to his own time, but his chapters are tedious beyond * Griffith's Cuvier, part xxxix. 289. On Colours, ii. 431. endurance. + Mem. sur les Mollusq. i. 4, 5. |