Scientijic InteUigence — Botany. 381 



xxxiv., 238 ; Annuaire dc Chimie, 1846, p. 271). — Glaucophane 

 comes from the island of the Cyclades, and resembles indicolite. It 

 has a prismatic foliated structure, a pure blue colour seen by re- 

 fraction ; sp. gr. 3-103 — 3-113 ; powder feebly attracted by 

 the needle. The mean result of two analyses is as follows : — 

 silica 56'49, alumina 12"23, protoxide of iron 10-91, protoxide of 

 manganese 0-50, magnesia 7'97. lime 2-25, soda with traces of 

 potash 9-28 = 99-63. It resembles Wichtyne from Finland in com- 

 position. 



BOTANY. 



24. Chinese Method of Colouring Green Teas. — During a visit 

 which I paid to a tea manufactory in the city of Shanghae, I hap- 

 pened to meet some merchants who came from the celebrated green 

 tea district of Wheychou. Thinking this a good opportunity for ob- 

 taining some information regarding the mode of colouring green 

 teas, and, as I was accompanied by Mr M. Donald, an excellent 

 Chinese scholar, I had some questions put to them on this subject. 

 They would not acknowledge that any colouring matter was used in 

 the manufacture of their teas, and pretended to laugh at the idea of 

 such a thing. They said, moreover, that they were aware the prac- 

 tice of colouring was a common one about Canton, where interior 

 teas were made, but that they never coloured their teas in Whey- 

 chou. They then skilfully enough tried to change the subject by 

 telling us, that we should not give credence to all we heard. " If 

 we did so," said they, " we would make some strange mistakes with 

 regard to the productions and manufactures of your country. For 

 example," they continued, " it is commonly reported that you buy 

 your teas in order to convert them into opium, and resell them in 

 that form to us. Now, we do not believe that you do tliat ; and 

 neither should you believe all you hear about the colouring of our 

 green teas." After giving us this sage advice, they asked us very 

 gravely, how we used this tea in England, — and if it was true that 

 we had the leaves boiled and beat up with sugar and milk ! 



It is, however, a difficult tlung to get the truth out ol a China- 

 man : and from information whicli I had received, I knew quite well 

 that our Wheychou friends were deceiving us in the present in- 

 stance. Shortly afterwards I had an opportunity of seeing the whole 

 process ; and as it is one of considerable interest, I noted it down at 

 the time with great care, and now send you a copy of my observa- 

 tions. 



The superintendent of the tea makers managed the colouring part 

 of the business himself. In the first place, he procured a portion of 

 indigo, which lie threw into a porcelain bowl, not unlike a cliemist's 

 mortar, and crushed it into a fine powder. He then burned a quan- 

 tity of gypsum in the charcoal fires wliich were roasting the tea. 

 The object of this was to soften the gypsum, in order that it might 



VOL. XLVII. NO. XCIV. — OCTOBER 1849. 2 C 



