270 THE TEIN-CHING, OR CHINESE INDIGO. 



ance, and covers a large tract of country. It is grown in rows, 

 a few inches apart, and at a distance looks like a field of young 

 turnip or cabbage plants. In June, 1844, when I was in that 

 country, the plants were from six inches to a foot in height, and 

 being considered in perfection the natives were busily employed 

 in cutting them and removing them to the manufactory. One 

 of these places which I inspected was close on the banks of the 

 canal, and was placed there for the convenience of the farmers, 

 who brought their leaves in boats from the surrounding country, 

 as well as to be near the water, a large quantity of which was 

 requisite in the manufacture. It consisted of a number of round 

 tanks, which are built for the purpose of steeping the leaves. 

 The leaves are thrown into the tanks and covered with water, 

 and, after remaining for a certain length of time, the juice is 

 drawn off into other tanks, where I believe it is mixed with 

 lime. The colour of the liquid at first is a kind of greenish 

 blue, but after being well stirred up and exposed to the air it 

 becomes much darker and very like the well-known indigo of 

 commerce. I suppose it is thickened afterwards by evaporation 

 in some way, but that part of the process did not come under 

 my observation. 



I am very much inclined to believe that this is the dye used 

 to colour the green teas which are manufactured in the north of 

 China for the English and American markets ; this, however, is 

 only conjecture. 



The plant has a half-shrubby stem covered with a fine bloom. 

 Its root-leaves are oval-lanceolate, on long stalks, sharp pointed, 

 slightly toothed, and somewhat fleshy ; those on the upper part 

 of the stem, near the flowers, are linear. The stem is decum- 

 bent, a foot and a half long, and divided at its extremity into 

 several drooping racemes about 6 inches long ; on its sides it 

 bears here and there small clusters of leaves like those of the 

 root. Flowers very small, yellow. Silicles black, quite smooth, 

 6 lines long by 2 wide in the broadest part, oblong, obtuse at 

 each end, a little contracted below the middle, with a thin 

 edge and a single median line. 



It seems to be a new species of Isatis, perfectly distinct from 

 all previously discovered. It belongs to the Glastum division, 

 or true Woads, among which its dwarf, half-shrubby habit and 

 acute, lanceolate, long-stalked leaves are conspicuous. I pro- 

 pose to call it Isatis indigotica, and to distinguish it by the fol- 

 lowing technical character : — Isatis (Glastum) indigotica ; suf- 

 fruticosa, foliis radicalibus glaucis ovali-lanceolatis latitudine ter 

 longioribus obsolete dentatis, caulinis linearibus siliculis line- 

 aribus glabris stigmate sessili coronatis medio paululum con- 

 strictis et basi anorustioribus. 



