234 
WANDERINGS IN CHINA. 
Chap. XIV. 
stream divided into many branches, and meandering 
amongst the roots of the newly planted trees. As there 
was no stream there before, I went up to examine its 
source, and found that it had been led from a neigh- 
bouring ravine ; a work more easy than carrying a large 
supply of water in buckets, and at the same time more 
effectual. 
Several other summer-crops are cultivated in the low 
lands. In the southern provinces, for instance, we find 
large quantities of the Nelnmhium speciosum grown for 
its roots, which are much esteemed ; the Trapa bicorniSy 
the castor-oil plant, Scirpus tuherosus, Convolvulus rep- 
tans, and several other vegetables, for which there is 
a great demand in all Chinese towns. The sugar-cane, 
also, is extensively grown both in the provinces of 
Quan-tung and Fokien, and probably in other parts of 
the empire. 
In the district of Kiangsoo my attention was directed 
to a plant called TeiTV-ching, which is largely cultivated 
by the inhabitants for the sake of its blue dye. In the 
southern provinces a great deal of indigo (Indigofera) 
is grown and manufactured, in addition to a large quan- 
tity which is annually imported from Manila and the 
Straits. In the north, however, the plant which we call 
indigo is never met with, owing, I suppose, to the cold- 
ness of the winters; but its place is supplied by the 
Teirirching {Isatis indigotica), the leaves of which are 
prepared in the same manner as the common indigo. 
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. I suppose it is thickened 
