Page:Popular Science Monthly Volume 20.djvu/374

360 Japonica and other species from China and Japan are favorite cultivations of the greenhouse in Europe and this country. Nowhere in the world but on the borders of the Himalayas and in the wild regions of Assam is the tea-plant found growing uncultivated, but it was not discovered in this its natural habitation until the present century. As a cultivated plant, the Chinese have certainly had it since the fourth century, and they claim it to be indigenous to their own soil—just as confidently as they claim the parentage of numerous valuable articles. China has given tea to the world, and has furnished a favorable home to the plant, which is nevertheless quite as well suited in its native land, farther east. When it became known in England that the tea plant grew native in the highlands of the Himalayas, English companies engaged extensively in the cultivation of tea in that region, and finally, after the correction of notable failures in methods of culture and of cure, it appears that the finest teas of Asia are those of these mountain-plains and the choicest plants are of variety Assamica, lately propagated from the wild shrub of the mountains.

A child would ask the question, What is there so very good in the tea-plant or in its dry leaf? And a philosopher may well ask, What is there about it, that this article has had a commercial history since the early middle ages, and men toil to till it, and with infinite detail to pick it and dry it and roll it, and spread and stir and roast and toss it, and then carry it over the globe in quantities to distribute for every household and amounting in sum-total to a quarter of a billion of pounds every year? In the first place, what does the tea-leaf contain—the fresh leaf from the wild bush of the mountains, never gathered for use, or the leaf picked on the tea-farms and carried dry to your tea caddy—what kinds of compounds are in it, and can no other plant than this produce them?

To leave out a long story of progressive investigations, and to say nothing of the ways and means of analysis, the chief constituent to be named is the alkaloid theine. When separated from the other constituents of the tea-leaf, so as to be seen in its perfect purity, theine appears in snow-white, silky, filiform crystals, flexible and fragile, without odor, but having a mildly bitter taste. It dissolves readily in ten times its quantity of boiling water, and more slowly in a larger proportion of boiling water. It does not vaporize or decompose in the least at water-boiling heat; it melts at higher temperature and vaporizes slowly at about 360° Fahr., without decomposition. Chemically, it is a compound of the four organic elements, and is classified within the borders of the great group of alkaloids, but it differs distinctly from all other alkaloids (except its near relative, theobromine) in various chemical characteristics. It has, also, a much larger proportion of nitrogen than the other natural alkaloids. But it remains an important consideration that this crystalloid constituent of the tea-leaf is built on the chemical type of the alkaloids, a class of bodies which