360 Robert Warrington, Esq., on the 



Additional Observations on the Green Teas of Commerce. 

 By Robert Warrington, Esq., F.C. 



Since the publication of my last communication on this 

 subject, read before the Society, May 19, 1851,* a series 

 of microscopical and chemical examinations have been pub- 

 lished in the Lancet of 9th August 1851, which have induced 

 me to institute some additional experiments, the results of 

 which may not be without interest to our readers, particu- 

 larly, as they tend to remove a curious anomaly that has 

 lately arisen. In the series of examinations alluded to, it is 

 stated that several of the specimens of the green tea sub- 

 mitted to investigation, were coloured with indigo mixed 

 with porcelain clay ; and this is followed by an examination of 

 some of the colouring materials themselves used at Canton for 

 this purpose, and which had been obtained from the Museum 

 at Kew Gardens. As I had statedf that, up to that period, no 

 sample in which indigo had been employed as an artificial 

 colouring agent for green teas had come under my notice, 

 I felt it incumbent on me to investigate the matter. For 

 this purpose I applied to Sir W. Hooker on the subject, and 

 he allowed me in the handsomest manner to take from the 

 cases in the Museum, small portions of the materials for ex- 

 amination, and also favoured me with the loan of the manu- 

 script journal of Mr Berthold Seeman, by whom the speci- 

 mens had been collected while at Canton, as naturalist of 

 H. M. Ship ' Herald,' then on a survey in that quarter of 

 the globe. As these documents have been since published, 

 and as the subject opens some interesting particulars, I have 

 taken the liberty of appending his account in his own words. J 



* This Communication is transfered to our Journal, vol. li., p. 240. [Ed. 

 Edin. Phil. Journ.] 



t Quart. Jour. Chem. Soc. iv,, p. 136. 



I Hooker's Journal of Botany, and Kew Garden Miscellany, No. 37, for 

 January 1852. " In the Manual of Scientific Inquiry, you ask, whether, in the 

 northern provinces of China, indigo or any other vegetable dye is used in 

 colouring green tea ? Whether different processes of dying are pursued in the 

 north from those of the south I cannot say, but it is certain that around Canton, 

 whence great quantities are annually exported, the green tea is dyed with 



