667 



colouring the green teas being Prussian blue, because some doubts 

 have been thrown on this subject from various quarters. Mr. Bruce 

 thus states :* — " The Chinese call the former (the indigo) Youngtin, 

 the latter (the sulphate of lime) Acco^ Now I am favoured with the 

 opinion of Mr. J. Reeves on this point, whose knowledge and expe- 

 rience render him most competent to decide in such a case ; he be- 

 lieves that indigo is never employed for the colouring used on tea, 

 that the term Youngtin, as used by Mr. Bruce, should be Yong-teen, 

 foreign blue, the name given by the Chinese to Prussian blue in con- 

 tra-distinction to Too-teen, native blue or indigo. This, I think, is 

 very conclusive evidence, and shows that Mr. Bruce's statement was 

 erroneous. 



In another quarter a surmise has also been published on this same 

 point. Mr. Fortune, in his entertaining work on China,t says, speak- 

 ing of the ingredients used in dyeing the northern green teas for the 

 foreign market, p. 201, " There is a vegetable dye, obtained from Isa- 

 tis Indigotica, much used in the northern districts, and called Tein- 

 ching, and it is not unlikely that it may be the substance which is 

 employed ;" again, at p. 307, " I am very much inclined to believe 

 that this (the Tein-ching) is the dye used to colour the green teas 

 which are manufactured in the north of China, for the English and 

 American markets," This question, however, I think, is now satis- 

 factorily settled, and the experimental evidence I had adduced of the 

 material being Prussian blue of a darker or paler tint, placed beyond 

 a doubt by a positive demonstration ; for Mr. Fortune has forwarded, 

 from the north of China, for the Industi'ial Exhibition, specimens of 

 these materials, which, from their appearance, there can be no hesita- 

 tion in stating are fibrous gypsum (calcined), turmeric root, and Prus- 

 sian blue ; the latter of a bright pale tint, most likely from admixture 

 witli alumina or porcelain -clay, which admixture may account for the 

 alumina and silica found as stated in my previous paper, and the pre- 

 sence of which was then attributed possibly to the employment of 

 kaolin or agalmatolite. 



Mr. J. R. Reeves, in a letter to my friend, Mr. Thompson, dated 

 July 1, 1844, commenting on my paper, says : — " Mr. Warington's 

 experiments have led him to correct results as to the substances used, 

 which I know to be Prussian blue, gypsum (fibrous), and turmeric ; 

 the second being sulphate of lime; and the last, the 'yellow or 



* 'Keport on the Manufacture of Tea, &c.,' by C. A. Bruce, August 16, 1839. 

 t ' Three Years' Wanderings in the Northern Provinces of China,' by Robt. For- 

 tune. 



