896 INDIGO 



In the southern provinces of China a species of Indigofera is extensively culti- 

 vated for the sake of the dye which it affords. In the northern provinces two other 

 plants are employed by the inhabitants for the same purpose. Mr. Fortune, the 

 well-known Chinese traveller, to whom we owe the description of these plants 

 and of the process of manufacturing indigo from them, states that one of them is 

 grown in the neighbourhood of Shanghae, and he has given it the name of Isatis 

 indigotica. The other, which is a species of Justicia, is largely cultivated in the 

 hilly country near Ningpo, or rather in the valleys among the hills. It seems to be 

 easily cultivated; it grows most luxuriantly, and is no doubt very productive. 

 Having evidently been introduced from a more southern latitude, it is not hardy in 

 the province of Chekiang any more than cotton is about Shanghae ; but nevertheless 

 it succeeds admirably as a summer crop. It is planted at the end of April or beginning 

 of May, after the spring frosts are over, and it is cleared from the ground in 

 October. During this period it attains a height of a foot or a foot and a half, becomes 

 very bushy, and is densely covered with large green leaves. It is cut before any 

 flowers are formed. The plants are grown, not from seed but from cuttings. These 

 cuttings consist simply of a portion of the stems of the previous year, which after 

 being stripped of their leaves are tied into bundles, each containing upwards of 

 1,000. and kept during the winter in a dry shed or outhouse, where after being firmly 

 packed together they are banked round with dry loam, and covered with straw or 

 litter so as to protect them from the frost. During the winter months the cuttings 

 remain green and plump, and although no leaves are produced a few roots are 

 generally found to be formed, or in the act of forming, when the winter has passed 

 and the season for planting has come round. In this state they are taken to the fields 

 and planted. The weather during the planting season is generally showery, as this 

 happens about the change of the monsoon when the air is charged with moisture. A 

 few days of this warm showery weather is sufficient to establish the new crop, which 

 now goes on growing with luxuriance and requires little attention during the summer, 

 indeed none except keeping the land free from weeds. In the country where this dye 

 is manufactured there are numerous pits or tanks on the edges of the fields. They are 

 usually circular in form, and have a diameter of about 11 feet and a depth of 2 feet. 

 About 400 catties ' of stems and leaves are thrown into a tank of this size, which is 

 then filled to the brim with clear water. In five days the plant is partially decom- 

 posed, and the water has become yellowish-green in colour. At this period the 

 whole of the stems and leaves are removed from the tank with a flat-headed broom 

 made of bamboo-twigs. When every particle has been removed, the workmen em- 

 ployed give the water a circular and rapid motion with the brooms just noticed, which 

 is continued for some time. During this part of the operation another man has 

 employed himself in mixing about thirty catties of lime with water, which water has 

 been taken out of the tank for the purpose. This is now thrown into the tank, and 

 the rapid circular motion of the water is kept up for a few minutes longer. When 

 the lime and water have been well mixed in this way the circular motion is allowed to 

 cease. Four men now station themselves round the tank and commence beating the 

 water with bamboo rakes made for the purpose. The beating process is a very 

 gentle one. As it goes on, the water gradually changes from a greenish hue to a 

 dingy yellow, while the froth becomes of a beautiful bright blue. During this process 

 the head workman takes a pailful of the liquid out of the tank and beats it rapidly 

 with his hand. Under this operation it changes colour at once, and its value is 

 judged of by the hue it presents. The beating process generally lasts for about 

 half an hour. At the end of this time the whole of the surface of the liquid is 

 covered with a thick coating of froth of the most brilliant colours, in which blue 

 predominates, especially near the edges. At this stage, it being desirable to incor- 

 porate the froth with the liquid below it, it is only necessary to throw a small quantity 

 of cabbage-oil on the surface of the froth. The workmen then stir and beat it 

 gently with their flat brooms for a second or two, and the whole instantly disappears. 

 The liquid, which is now darker in colour, is allowed to repose for some hours, 

 until the colouring matter has sunk to the lower stratum, when about two-thirds of 

 the liquid is drawn off and thrown away. The remaining third part is then drawn into 

 a small square tank on a lower level, which is thatched over with straw, and hero it 

 remains for three or four days. By this time the colouring matter has separated 

 itself from the water, which is now entirely drained off, the dye occupying throe or 

 four inches of the bottom in the form of a thick paste and of a beautiful blue colour. 

 In this state it is packed in baskets, and exposed for sale in all the country towns in 

 this part of China. Like the Shanghae indigo, made from Isatis indigotica,, it is 

 called Tien-ching' by the Chinese. Gardeners Chronicle and Agricultural Gazette^ 

 Aprils, 1854. 



1 A Chinese catty Is c^ual to 1J Ib. 



