On poisonous Tea-leaves. ~ 213 



the vender of the poisonous tea-leaves, whose whole support de- 

 pended on the rectitude of a fair tradesman, to inquire into the 

 fraud committed upon him. He consulted some of his friends 

 who received their tea from the same quarter, and it became 

 evident that the deceptions practised in this diabolical branch of 

 commerce were greater than was by him expected. The poi- 

 sonous tea had all the appearance of the leaves of genuine Hyson '^ 

 but it was noticed bv the chemist who examined the suspected 

 samples, that a portion of tlie leaves when infused in Ijoiling 

 water became speedilv resolved into a fine powder, and that part 

 of this alone remained in an entire state, so as to make it possi- 

 ble to recognise the vegetable structure; and this led to the opi- 

 nion that the manufacturer of the poisonous commodity had em- 

 ployed the dust of the leaves of Hyson tea, [the sale of which 

 forms a regular business with many tea-brokers], and moulded 

 it, probably by means of a small quantitv of mucilage, into a com- 

 pound possessing in every respect the external characters of 

 genuine Hyson tea. This fraud may therefore be detected by 

 merely throwing the sophisticated tea-leaves into warm water, 

 which instantly causes them to fall into a fine powder, which 

 speedily settles to the bottom of the vessel. The infusion, when 

 mingled with liquid ammonia, affords a bright blueish green co- 

 lour, indicating the presence of copper. But the presence of this 

 metal mav be more strikingly rendered obvious, by mixing two 

 parts of the suspected tea-leaves with one of nitrate of potash 

 (saltpetre), and throwing the mixture into a crucible kept red hot 

 iii a common fire. The whole of the vegetable matter of the 

 tea will thus become destroyed, and the copper remain behind 

 in combination with the alkali of the saltpetre. If water there- 

 fore be poured into the crucible to dissolve the mass, the pre- 

 sence of copper will be incontrovertibly rendered obvious, by 

 the admixture of liquid ammonia, which imparts to the fluid a 

 beautiful sapphire blue colour. 



I am with respect, sir, 



Your humble servant, 

 Grove Cottage, Lisson Green, Sept. 22, 1819. James MlLL.\R. 



P. S. — Mr. Accum, in his Report, remarks that the copper 

 employed for colouring the tea is in the state of a carbonate, and 

 not as verdigris, which he states totally inapplicable for its frau- 

 dulent purpose of giving a bloom to the tea-leaves. I need not 

 remind your readers, that all preparations of copper are deadly 

 poisons. — J. M. 



XXXVIII. On 



