THE TEIN-CIIIXG, OR CHINESE INDIGO. 



269 



the tubers were injured by slugs ; and on this account the rela- 

 tive amounts of total produce, it is presumed, will afford the best 

 criterion of the value of the respective substances as manures — 

 so far at least as such can be determined by the experiments of 

 only one season. 



It appears from the above table of results, that Guano, of the 

 description marked E, from Gibbs, affords the most profitable 

 return, after deducting the price of the manure ; and next to it 

 Potter's Artificial Guano ; after which rank in the same respect, 

 Gibbs's Guanos, M A, C, and G Z,. The produce of the latter 

 is exceeded by that where Bone-dust was employed ; and the 

 MA. and C. Guanos by Charcoal-dust, and Sulphate of Mag- 

 nesia ; but the expense of these is too great in proportion to the 

 B^turn. 



/. 



XLI. — A Notice of the Tein-cMng, or Chinese Indigo. By 

 Mr. R. Fortune, Superintendent of the Hot-house Department 

 in the Society's Garden. 



(Communicated Sept, I, 1846.) 



When in the north of China my attention was directed to a 

 plant largely cultivated by the inliabitants for the sake of its 

 blue dye. In the southern provinces a considerable quantity of 

 indigo (Indigofera) is cultivated and manufactured, besides a 

 large portion which is annually imported from Manilla and the 

 Straits. In the north, however, the plant which we call indigo 

 is never met with — owing, I suppose, to the coldness of the 

 winters — but its place is supplied by this Isatis indigotica, or 

 the " Tein-ching " as it is called by the Chinese. 



I met with it in the Nanking cotton district, a few miles west 

 from Shanghae, where it is considered a plant of great import- 



