INDIGO.

It is more than probable that indigo, so early as the time of Dioscorides and Pliny, was brought to Europe, and employed there in dyeing and painting. This I shall endeavour to show; but under that name must be understood every kind of blue pigment, separated from plants by fermentation, and converted into a friable substance by desiccation; for those who should maintain that real indigo must be made from those plants named in the botanical system Indigofera tinctoria,would confine the subject within too narrow limits; as the substance which our merchants and dyers consider as real indigo is prepared, in different countries, from so great a number of plants, that they are not even varieties of the same species.

Before the American colonies were established, all the indigo employed in Europe came from the East Indies; and till the discovery of a passage round the Cape of Good Hope, it was conveyed, like other Indian productions, partly through the Persian Gulf, and partly by land to Babylon, or through Arabia and up the Red Sea to Egypt, from which it was transported to Europe. Considering this long carriage, as the article was not obtained, according to the Italian expression, a drittura, that is, in a direct manner, it needs excite no surprise, that our knowledge, in regard to its real country and the manner of preparing it, should be exceedingly uncertain and imperfect. Is it astonishing that articles, always obtained through Arabia, should be considered as productions of that country; and that many commodities which were the work of art, should be given out to be productions of nature? For more than a hundred years the Dutch purchased from the Saxons cobalt, and smalt made from it, and sold them again in India; and the Indians knew as little where and in what manner the Dutch obtained them, as the Saxons did the people who were the ultimate purchasers and consumers. The real nature of indigo was not generally known in Europe till the Europeans procured it from the first hand; yet long after that period, and even in the letters-patent obtained on the 23rd of December 1705, by the proprietors of the mines in the principality of Halberstadt and the county of Reinstein,

indigo was classed among minerals on account of which works were suffered to be erected; but this only proves the individual ignorance of the undertakers, and also of their superiors, when they read what they had written, and confirms the justness of Ovid's advice,

Disce bonas artes, moneo, Germana juventus;

Non tantum trepidos ut tueare reos.

What Dioscorides calls Indicon, and Pliny and Vitruvius Indicum, I am strongly inclined to believe to have been our indigo1. It was a blue pigment brought from India, and used both in painting and in dyeing. When pounded it gave a black powder, and when suspended in water it produced an agreeable mixture of blue and purple. It belonged to the costly dye-stuffs, and was often adulterated by the addition of earth. On this account, that which was soft without any roughness, and which resembled an inspissated juice, was esteemed the best. Pliny thinks that pure indigo may be distinguished from that which is adulterated by burning it, as the former gives an exceedingly beautiful purple flame, and emits a smell similar to that of sea-water. Both he and Dioscorides speak of two kinds, one of which adheres to reeds, in the form of slime or scum thrown up by the sea; the other, as Dioscorides says, was scraped from the sides of the dyepans in the form of a purple-coloured scum; and Pliny expressly remarks, that it was collected in this manner in the establishments for dyeing purple. The former relates also, that Indicum belonged to the astringent medicines; that it was used for ulcers and inflammations, and that it cleansed and healed wounds.

This is all, as far as I know, that is to be found in the works of the ancients respecting Indicum. I have given it at full length, as accurately as possible, and I have added, in order that the reader may be better able to compare and judge, references to the original words of the authors. Indicon, it is true, occurs in other passages; but it was certainly different from the one already mentioned. I allude, for example, to the black Indicon of Arrian and the Indicon of Hippocrates. Of the former I shall treat in particular hereafter; 1 Dioscor. lib. v. cap. 107, p. 366. Пepì 'Ivdikov.

2 Plin. lib. xxxv. cap. 6, § 27, p. 688; and Isidorus, Origin. lib. xix. cap. 7, p. 464.

and in regard to the latter, I refer to the author quoted in the note below'. It is not at all surprising that these names should be applied to more Indian commodities, since at present we give to many kinds of fruit, flowers, fowls and other things, the appellation of Indian. The ancients, indeed, were not so careful as to distinguish always, by a proper addition, the many articles to which they gave the name of Indica; and they had reason to expect that their contemporaries would readily comprehend by the connexion, the kind that was properly meant. Their commentators, however, in later times have for the most part thought only of one species or thing, and by these means they have fallen into mistakes which I shall here endeavour to rectify.

Everything said by the ancients of Indicum seems to agree perfectly with our indigo. The proper country of this production is India; that is to say, Gudscharat or Gutscherad, and Cambaye or Cambaya, from which it seems to have been brought to Europe since the earliest periods. It is found mentioned, from time to time, in every century; it is never spoken of as a new article, and it has always retained its old name; which seems to be a proof that it has been used and employed in commerce without interruption.

It is true, as the ancients say, that good indigo, when pulverized, is of a blackish colour. The tincture, however, is partly blue and partly purple; but under the latter term we must understand an agreeable violet, and not, as is often the case, our scarlet. It is true also that good indigo is soft or smooth to the touch when pounded; it floats on water, and at present, as in the time of Pliny, is adulterated and rendered heavier by the admixture of some earth, which in general, as appears, is fine pounded slate3. It is further true that

Neither

1 Foesii Economia Hippocratis. Francof. 1588, fol. p. 281. 2 "Eyxvλov means also juicy, or something that has a taste. of these significations is applicable here, where the subject relates to a substance which is dry and insipid, or at any rate which can possess only a small degree of astringency. It must in this place denote an inspissated or dried juice; but I can find no other passage to support this meaning.

3 In Pliny's time people coloured a white earth with indigo, or only with woad, vitrum, in the same manner as coarse lakes and crayons are made at present, and sold it for indigo. One of them he calls annularia, and this was one of the sealing earths, of which I have already spoken in the first volume. In my opinion it is the same white pigment which Pliny

the purity of it can be discovered by burning it. Indigo free from all foreign bodies leaves but little ash, while that which is impure leaves a large quantity of earth. Pliny, perhaps, did not rightly understand this test by fire, and added from conjecture, what he says in regard to the colour of the flame and the smell of the smoke, that this proof might not remain without an explanation. It is, however, possible that those who considered indigo to be sea slime, imagined that they perceived in it a smell of sea-water. A naturalist of modern times, who refers petrifactions to Noah's flood, believed that he could smell sea-water in them after the lapse of so many thousand years.

Indicum, on account of its long carriage by land, must have been dear, and therefore it was one of those pigments which the ancient painters, who were often poor slaves, were not accustomed to keep in any quantity by them, and with which it was necessary they should be supplied by those for whom they executed paintings1. Our indigo was also exceedingly dear till it was cultivated in the West Indies, where the value of it decreased as long as good land was plentiful and the price of labour was lessened by the slave-trade.

That indigo, which at present is used only by dyers, should have been employed also for painting, needs excite no surprise. It was applied to this purpose till the invention of painting in oil, and the discovery of Prussian blue, smalt and other pigments of a superior quality. It is even still used by landscape-painters to produce a pale gray; but it will not harmonise with oil. As to the medical properties of indigo, I can at any rate show that the experiments made with it at the end of the seventeenth and the beginning of the eighteenth century fully confirm the high encomium bestowed by Dioscorides upon his Indicum. There was a time when the former was much prescribed and recommended. At present our physicians are acquainted with purer and more powerful remedies than indigo, the internal use of which, as the fer

immediately after calls annulare: "Annulare quod vocant, candidum est, quo muliebres picturæ illuminantur." These words I find nowhere explained, and therefore I shall hazard a conjecture. Pliny, I think, meant to say that "this was the beautiful white with which the ladies painted or ornamented themselves."

1 Plin. lib. xxxv. § 12, p. 684.—Vitruv. lib. vii. cap. 14.

mented mass is prepared in copper vessels, must be attended with suspicion.

That the author, so often mentioned already, was not acquainted with the preparation of indigo, cannot be denied. It would, indeed, have been extraordinary had the account of it reached the Greeks and the Romans undisguised by fables, added either to answer the purposes of the interested merchant, or accidentally in the course of its long journey, in passing through so many countries and languages. It appears to me, however, that through these it may still be discovered; and in all probability we should be better able to form some idea of it were the oldest method of making indigo still known. In the slime deposited on the reeds, I think I can remark the first degree of fermentation, or commencement of putrefaction, without which the pigment could not be separated. Who knows whether the indigo plants in the earliest times were not deposited in pits or in stagnant water, in the same manner as our flax and hemp? Who knows whether after putrefaction they were not taken out, and the colouring parts adhering to them washed off and collected? The quantity indeed obtained by this process would not be great, and at present a much better method is employed; but the improvements made in every art have been gradual. The old inhabitants of the Canary islands scratched their land with the horns of oxen, because they were not acquainted with the spade, and far less with the plough. The above conjecture will appear much more probable, when it is known that in many parts of India the plants were formerly placed in large pits; and in Malta, where indigo was still cultivated in the seventeenth century, they were put into reservoirs or basins in order to ferment1. If this was usual in the oldest times, it may be easily seen how fabulous accounts might arise. Indigo was a slime attracted from the water by a reed, which the indigo plant, stripped of its bark, was considered to be.

1 Tavernier, ii. p. 112. We are told so in Malta Vetus et Nova a Burchardo Niederstedt adornata. Helmest. 1659, fol. lib. iv. cap. 6, a work inserted in Grævii Thesaurus Ital. vi. p. 3007. This man brought home with him to Germany, after his travels, a great many Persian manuscripts, which were purchased for the king's library at Berlin. Niederstedt, howis not the only person who speaks of indigo being cultivated in Malta. Bartholin, Epist. Med. cent. i. ep. 53, p. 224, says the same.

ever,