Camellia Sesanqua.
“A Plant very like the Tea flourished at this time on the tides and the very tops of mountains, where the soil consisted of little more than fragments of stone crumbled into a sort of coarse earth by the joint action of the sun and rain. The Chinese call this plant Cha-whaw, or Flower of Tea, on account of the resemblance of one to the other; and because its petals, as well as the entire flowers of the Arabian jessamine, are sometimes mixed among the Teas, in order to increase their fragrance.
“This plant, the Cha-whaw, is the Camellia Sesanqua of the botanists, and yields a nut, from whence is expressed an esculent oil equal to the best which comes from Florence. It is cultivated on this account in vast abundance; and is particularly valuable, from the facility of its culture, in situations fit for little else.” It is delineated on the opposite page.
As green Tea is by some suspected to have been cured on copper, they have attributed the verdure to be derived from that metal (Sect. VII.); but, if there were any foundation for this supposition, the volatile alkali, mixed with an infusion of such Tea, would detect the least portion of copper, by turning the infusion blue[48].
Others have, with less propriety, attributed the verdure to green copperas[49]; but this ingredient, which is only salt of iron, would immediately turn the leaves black, and the infusion made from the Tea would be of a deep purple colour[50].
Is it not more probable, that some green dye, prepared from vegetable substances, is used for the colouring?