508 Mr. Warington on the Green Teas of Commerce. 



and a white powder, with a slight shade of brown, was ob- 

 tained. This dissolved by boiling in dilute hydrochloric acid, 

 and when tested with solution of chloride of barium gave in- 

 dications of sulphuric acid ; it was then evaporated to dry- 

 ness and again acted upon by very dilute hydrochloric acid; 

 a trace of silica remained undissolved. Solution of ammonia 

 being added threw down a little alumina and oxide of iron, and 

 the ammoniacal solution treated with oxalic acid gave a pre- 

 cipitate of oxalate of lime. A second portion of the powder 

 after calcination was boiled for some time in distilled water, 

 and yielded a solution containing sulphate of lime ; this latter 

 substance, therefore, and some other body containing silica, 

 alumina, and perhaps lime, formed the white powder observed. 

 This substance I believe to be kaolin, or powdered agalmato- 

 lite, the figure stone of the Chinese. I venture this conjecture 

 not only from the ingredients found, but also from the gloss 

 which the rubbed parts of the curled leaves always assume, and 

 which these materials would be well fitted to produce. 



Four or five other samples of green teas were then sub- 

 mitted to the same method of examination, and only one of 

 them proved to be free from these blue granules; this sample 

 was a high-priced tea, and had been purchased about two 

 years ; it appeared covered with a very pale blue powder, in- 

 stead of the white with the blue particles interspersed, as ex- 

 hibited by the others. 



Being still in doubt as to whether this powder and colouring 

 was an adulteration practised in this country or not, I applied 

 to a most extensive wholesale dealer of the highest respecta- 

 bility, and from him obtained a series of samples, each being 

 an average from a number of original chests, and from these 

 I gathered the following results by examination, as before, with 

 the microscope. No. 1. Imperial. The leaf, where seen be- 

 neath the superficial coating, was of a bright olive brown 

 colour, with small filaments on its surface; it was covered 

 with a fine white powder and with here and there a minute 

 bright blue particle, at times having the appearance of a stain. 

 No. 2. Gunpowder. Similar to No. 1, but the filaments not 

 visible: this may have arisen from the tight and close man- 

 ner in which the leaf was curled. No. 3. Hyson. The same 

 as No. 1, the blue particles being perhaps more frequent. 

 No. 4. Young Hyson. The same. No. 5. Twankey. The 

 leaf of this had more of a yellow hue, and was profusely 

 covered with white powder, having the blue particles also 

 more thickly strewn over the surface. It was evident from 

 the examination of these teas that they arrive in this country 

 in an adulterated or factitious state. 



