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DYEING AND CALICO PRINTING.

During the middle ages indigo had become almost unknown in Europe, butit is quite certain that now and then some small quantities came to Italy byway of Alexandria, and it was used there to some extent. The old Dutch EastIndia Company (1602) first brought indigo from India via the Cape to Europein large quantity. The introdudtion of this dye-ware into Europe gave rise atvarious times to legal ordinances and adts of Parliament in England prohibitingits use. It was called a “ devilish drug,” pernicious to the growers of woad(Isatis tinctoria), and injurious to the fabrics; but, notwithstanding severeopposition, as early as 1631 half a million pounds of indigo were brought inone year to Amsterdam and sold at very high price. Shortly after the discoveryof America it was found that some parts of that country also produced plantsfrom which indigo could be obtained.

The plants which yield indigo are rather numerous, and do not all belong tothe same family, though none of them contain the colouring matter readyformed. It owes its origin to a peculiar colourless principle, about which morehereafter, and which is converted into indigotin by a process of fermentation.

Among the indigotin-producing plants the most important are the genusIndigofera, belonging to the natural order of the Legiminosece. The followingare the names of the more important plants cultivated for its produdtion:—Indigofera tinctoria, Indigofera disperma, Indigofera anil, Indigofera argentca.The following are less frequently planted, or, at any rate, less valuable :—Indigoferapseudotinctoria, hirsuta, sericca, cytisoides, trifoliata.

These plants are natives of Guzerat, but have been cultivated from timeimmemorial in the rest of Hindostan, especially Bengal, Java, the PhilippineIslands, and also in China, though there to a far more limited extent. TheSpaniards brought some of these plants over and acclimatised them in severalparts of their former extensive South American possessions. The roots ofthe Indigoferas are very fully developed, and the plant exhales, especiallytowards night time, a strong and somewhat disagreeable odour. The tasteof the leaves is disagreeable, and they putrefy rapidly when immersed inwater. The experience of the indigo planters in Java is that the natives whowork in the fadtories and handle the plant in various ways are liable to sufferfrom sexual impotence, accompanied by a temporary semi-lameness of thelower limbs. The exhalations emanating from indigo fields where the plantsare grown produce headache and nausea to those not accustomed to thesmell. Indigo is used internally as a therapeutic agent of some repute againstcataleptic and other fits.

The indigo plants are grown in India from seed sown in a loamy soil, pre-viously thoroughly well ploughed and dressed. The sowing seasons are inthe spring and autumn, according to the special kind of the plant, the natureof the soil, the situation of the field in reference to water supply, because onlow lying lands subjedt to inundations the crops must be gathered before therivers are swollen by rain. As soon as the young plants are sufficientlyforward they are re-planted in regular parallel rows, care being taken to weedout from the soil any useless parasitic plants. The flower buds are pulled offbefore they are fully developed, experience having taught that by so doing theleaves of the shrub become larger and yield more indigo, the colourablematter which produces that substance being chiefly present in the leaves. Insome localities the leaves, which have become bluish green, are pulled from