168 SEEDS. 



which proceed from the buds, are separated from the others ; these 

 after having been winnowed, receive a new touch of the fire, when they 

 acquire a leaden-gray color, and constitute the lea of the best quali- 

 ty, which in the Brazils passes by the name of Imperial or Uchim 

 tea. The leaves which remain upon the sieve are heated, winnowed, 

 and sifted again, and the produce is fine Hyson tea ; and by the 

 same means other varieties are procured, until at length a kind re- 

 mains upon the sieve consisting of the leaves that have not become 

 rolled up, which being added to the broken particles derived from 

 the winnowing operations, is called family tea, because it is consum- 

 ed upon the spot. 



During, and for some time after the drying, tea exhales an herba- 

 ceous and not very pleasant odor, which however becomes modified 

 in the course of time. The aroma of the Chinese teas is said to be 

 communicated to them by a highly odorous plant, which is believed 

 to be the Oleajiagrans. It is also said that the green tea is colored 

 by means of indigo ; but it is possible that the shades of color of the 

 different kinds of tea depend solely upon the degree of roasting 

 which they have undergone. Guillemin has said nothing of the 

 produce of the tea shrub in Brazil. In China, according to a man- 

 uscript of M. Carpena, a shrub with care will produce annually 

 during thirty or forty years from 2 lbs. to '2,\ lbs. of marketable tea. 



From the analysis of M. Mulder, tea appears to contain : 1st. A 

 volatile oil. 2d. Chlorophylle. 3d. Wax and resin. 4th. Gum. 

 6th, An extractive matter. 6th. A coloring matter. 7th. Azo- 

 tized substances analogous to albumen. 8th. Woody fibre and inor- 

 ganic salts. 9th. A particular crystalline principle, — theine or cof- 

 feine, which is ranked among the vegetable alkalies, and which is 

 also met with, as implied by the name, in coffee : this new principle 

 crystallizes in colorless needles of a silky aspect and bitter taste. 

 It is little soluble in alcohol and in ether ; water dissolves about 

 ^fjXh of its weight, and it sublimes without undergoing decomposi- 

 tion ; it is by sublimation, in fact, that Mr. Stenhouse proposes to 

 obtain it from tea. 



This is undoubtedly the principle which communicates to tea its 

 bitter taste, and several of its properties ; experiment has shown, 

 that when administered even in considerable doses it produces no ill 

 eflfect on the animal economy ; different kinds of tea, as might have 

 been presumed, contain it in different proportions. Mr. Stenhouse 

 obtained from 100 parts of 



Hyson 1.09 ofCoffeine 



Congou 1.02 " 



Assam 1.37 " 



Twankay, green 0.98 " 



SEEDS. 



Wheat. This valuable grain is the produce of several kinds of 

 triticum — winter wheat, and spring wheat, T. hybernum^ and T 

 mstivum, spelter, T. Spella, and T. rnonocon. 



Wheat is sown either upon a fallow or upon land that has carried 



I 



