Ohservations on Tea. 1?5 



There are some metallic substances also, which, in the 

 •ame case, acquire an electricity so sensible, that the energy 

 of its effects alone may serve to confirm the indications of- 

 fered by the other characters. Such are sulphurated copperj 

 which have no need of being passed eight or ten times over 

 cloth to make the first contact with the collector often pro- 

 duce repulsion between the straws of the electrometer, in 

 virtue of which the straws touch the sides of the glass flas]^ 

 in which they are suspended. 



To conclude; the metals have other properties which di- 

 stinguish them so clearly from each other, that the charac- 

 ters deduced from the preceding experiments will appear su- 

 perfluous; but I thought it would not be a matter of indif- 

 ference to collect and make known the results of these eji- 

 periments, considering them only as simple facts, con- 

 nected with a branch of natural philosophy, which for some 

 years has been doubly interesting by the beautiful discove- 

 ries to which metallic substances themselves have giveu 

 birth. 



■/' 

 XX. Ohervations en Tea. By Desfontaines*. 



XiiLL, Linnaeus, and others, have thought it necessary to 

 distinguish two kmds of tea; namely, bohea tea, thea 

 I'o/ieo ; and green tea, thea viridls ; because, according to 

 these writers, the one has six petals, and the other nine. 

 Linnasus adds, that the leaves of tne former are longer than 

 those of the latter. Such are the only characters which 

 establish the difference between tliem : but, according to the 

 observations of Dr. Lettsom, published in 1799, the num- 

 ber of the petals of the orceii tea and the bohea tree are 

 subject to vary from three to nme, so that the principal 

 character indicated by Hill and Linnceus is not admissible : 

 and as Lettsom cou'd find no other, lie considers, and with 

 justice, green tea and b(;hea tea to bt; two varieties arising 

 from the influence of chmate and soil. Thunberg, in his 

 Flora Japotilca, admits only one species, and he is of 

 opinion that the green tea is a variety of the bohea. Kemp- 

 fer also acknowledges only one species, which, like ali 

 cultivated plants, has produced several varieties. In a word, 

 the observations which I made on ^ome individuals culti- 

 vated in the garden of the Museum of Natural History, two 

 of which produced abundance of flowers" last year, have 



• From Annal£s du Museum National d' Hi stoire Naturtllr, No. iq. 



served 



