Some have conjectured that what in Arrian is named laccos chromatinos was our indigo, which indeed might be classed among the lakes, according to the present meaning of that word. Others understand by it gum-lac[632]. But I am unacquainted with any proofs that gum-lac was known at so early a period. I much doubt whether this meaning of the word lac be so old; and I must confess that the opinion of Salmasius appears to me highly probable, namely, that Arrian alluded to a kind of party-coloured garment: for besides the grounds adduced by Salmasius, it deserves to be remarked, that in the passage in question different kinds of clothes, and no other articles are mentioned. Besides, the epithet chromatinos is applied by the same writer, in the same sense, to other kinds of clothing. It cannot therefore be said that Arrian mentions our gum-lac, the origin of which word Salmasius endeavours to discover.
In the works of Galen, which have not yet been sufficiently illustrated, I have found Indicum nigrum only four times. In a place where he speaks of diseases of the eyes[633], he extols it on account of its cleansing quality; and says it can be used for wounds, when there is no inflammation. In another place[634], it occurs in three prescriptions for eye-salves. I have however endeavoured, but without success, to find in this excellent writer an explanation of what he calls Indicum; though he has explained almost all the different articles then used in the Materia medica. It appears therefore that the Greeks gave the name of Indicum to our indigo, and also to Indian black or Indian ink.
It however cannot be denied that, in opposition to this opinion, considerable doubts arise. Many who think that the black indigo (nigrum Indicum) of Pliny and Vitruvius was not ink, but our indigo, remark, that things of a dark blue or dark violet colour were by the Greeks and the Romans frequently named black; and therefore that the blue indigo might in this manner be called black[635]. But the examples adduced as proofs are epithets applied by the poets to dark-coloured flowers. Because nature produces no black flowers, the poets, who are fond of everything uncommon, extraordinary, and hyperbolic, call flowers black, when they are of so dark a tint as to approach nearly to black. Thus clear and deep water is called black. It is however hardly credible that painters and dyers, who must establish an accurate distinction between colours, should have spoken in so vague a manner. Salmasius suspects that Nil and Nir, the Arabic names of indigo, have arisen from the Latin word niger.
The objection, that Paulus Ægineta, the physician, in a passage where he refers to Dioscorides for the medical virtues of Indicum, applies to it the epithet black, seems to have more weight[636]. It may be added also, that the virtues, in general, which Galen ascribes to the Indicum nigrum, appear to be similar to those ascribed by Dioscorides to Indicum; and the latter in one place[637], where he speaks of the healing of wounds, uses only the expression Indicum, and not Indicum nigrum. It is particularly worthy of remark, that Zosimus, the chemist, declares the hyacinth colour of the ancients, that of woad, and the Indicum nigrum, to be the same[638] or similar. But to those who know on how slight grounds the ancient physicians ascribed medicinal qualities to many substances, it will not perhaps appear strange, that, in consequence of the same name, they should ascribe the same qualities to two different things. It is not improbable that in cases of external injury, for which the Indicum nigrum was recommended, indigo and Indian ink might produce as much or as little effect. I should consider of far greater importance the opinion of the chemist Zosimus; but unfortunately his writings have not yet been printed. The period in which he lived is still uncertain, and it is not known whether all the chemical manuscripts which bear that name were written by the same author.
From what has been said, I think it may, at any rate, be inferred, that in the time of Vitruvius and Pliny, indigo, as well as Indian ink, was procured from India, and that both were named Indicum. It is less certain that the Greeks called indigo Indicum, and Indian ink Indian black. Nay, it appears that indigo, on account of the very dark blue colour which it exhibits both when dry and in the state of a saturated tincture, was often named Indian black. In my opinion, it is proved also that, in the old dye-houses, the workmen collected the scum thrown up by the dye-pans, and dried it into a kind of lake or carmine.
I shall now prove what I have already asserted, that indigo was at all times used, and continued without interruption to be imported from India. I shall quote mention made of it in various centuries; but I am convinced that attentive readers may find instances where it occurs in many other writers.
The Arabian physicians, it is probable, all speak of indigo; but it is unfortunate that in this point we must depend upon very incorrect Latin translations. It appears also that they often repeat the information of the Greeks, in regard to articles of the Materia medica, without having been acquainted with them themselves. Rhases, who lived at the end of the tenth century[639], mentions, “Nil, alias Indicum.” Avicenna, who died in 1036, often speaks of indigo[640]; but in the margin of the wretched translation it is remarked, that under the term Indicum, alum (or much rather green vitriol) is to be understood. In a passage, however, where he speaks of dyeing the hair black, he certainly alludes to indigo, which, according to the translation, produced colorem pavonaceum, or a violet colour. In the Latin we find “Indicum indum bonum,” and this awkward expression Salmasius explains by remarking, that the words in the Arabic are Alusma Alhendia, that is, Indian woad. In the same place he mentions Indicum carmenum, a kind of indigo which did not dye so much a violet colour as a black, that is to say with the addition of green vitriol. Carmania, indeed, bordered on Gedrosia, which is the proper country of indigo, where the best is still prepared at Guzerat. In the explanation of some Arabic words, printed in my copy of Avicenna, Indicum is translated granum Nil. Serapion, about the end of the eleventh century, mixed together, as appears, every thing that the Greeks have said in regard to indigo and woad. Averroes, in the middle of the twelfth century, mentions the medicinal qualities of indigo as given by the Greeks, and adds, that it was much used for dyeing.
Muratori gives a treaty, written in Latin, of the year 1193, between the citizens of Bologna and Ferrara, which contains a list of those articles subject to pay duty. Among these occurs indigum[641]. In the thirteenth century, the celebrated Marco Polo, who spent twenty-six years in travelling through Asia, and even some parts of China, relates that he saw indigo, which the dyers used, made in the kingdom of Coulan or Coilum; and he describes the process for preparing it[642]. Much curious information in regard to the trade with this article, in the middle of the fourteenth century, is contained in the valuable work of Francesco Balducei Pegolotti[643]. We there find the names of different kinds, such as Indaco di Baldacca detto buccaddeo, in all probability from Bagdad, a city which in many old books of travels is called Baldach or Baldac; also Indaco del Golfo, Indaco di Cipri, Indaco Rifanti. Indigo, at that time, was imported in hides (cuojo), or in leather bags (otre), and also in boxes (casse). What this traveller says in regard to the signs by which its goodness may be known, is very remarkable. Nicolo Conti, who travelled through India before the year 1444, mentions endego among the merchandise of Camboia[644]. That the expression color indicus was used in the middle ages to denote blue mixed with violet, is proved by Du Cange. It appears to me therefore highly improbable that indigo should not be known to Rosetti, as Professor Bischof supposes[645]. In that important work on dyeing, however, which I mentioned long ago[646], it occurs several times, and always under the name endego.
I shall here make one observation, which is of some importance in the history of dyeing. It is found that in the middle ages the Jews maintained in the Levant a great many establishments for dyeing, and were the principal people who carried on this branch of business. Benjamin the Jew, who died in 1173, says in his travels, in speaking of some places, that “a Jew lived there who was a dyer;” or he remarks, in regard to others, that “most of the Jews followed the occupation of dyeing.” A scarlet-dyer lived at Tarento, and a purple-dyer at Thebes. At that period the Jews at Jerusalem had hired from the king a place particularly well-fitted for dyeing, on the express condition that no person besides themselves should be suffered to carry on there the same business[647]. I am fully aware that well-founded doubts have been entertained in regard to the credit which ought to be given to Benjamin’s narration, and Jewish vanity is everywhere well-known; but I do not see why he ought not to be believed in regard to this point; for it may very naturally be asked, why he should have falsely ascribed this occupation to his countrymen and no other? He speaks only once of a Jew glass-maker, a woollen- and a silk-weaver. To this may be added, that it is frequently stated in various authors, that the business of dyeing was carried on in Italy by the Jews. Thus, in the eleventh century, among the branches of revenue arising to the popes from Benevento, mention is made of the taxes paid by the Jews on account of their dye-houses. In the middle ages princes seem to have maintained dye-houses on their own account. Instances occur of their giving away, as presents, such establishments with all their apparatus[648]. A place of this kind was called tincta, tingta, or tintoria. This dye regale is to be deduced perhaps from the old establishments for dyeing purple, which could be formed only by sovereigns, and not by private individuals. Along with these tinctæ the Jews are often mentioned, so that it appears probable they were employed there as workmen.
There is reason therefore to conjecture that the Jews learned this art in the East, and that they employed in Italy the same pigments as were used in the dye-houses of the Levant. It is not improbable also, that in the room of woad, which was then cultivated in Italy, they introduced indigo, a substance richer in colouring matter, or at any rate, rendered it more common. The Italians were the first people in Europe who brought this art to a greater degree of perfection, as they did many others; and it can be proved that the knowledge of it was thence diffused to other countries. In the same proportion as this took place, indigo, in my opinion, banished the native woad, which was neither so advantageous, nor communicated so beautiful a colour as the Italians were able to dye with the former. The use of it became more extended when the productions of the East Indies were brought to Europe by sea, and particularly after it could be obtained from America at a much cheaper rate.