130 ELEMENTARY BOTANY. 



acem), has been cultivated for ages, and its native country is 

 now no longer known. It is an evergreen shrub or very small 

 tree, generally kept dwarf by pruning. The branches are very 

 numerous, bearing elliptical or lanceolate leaves, which are 

 two or three inches in length. The plants yield a small pick- 

 ing when three years old, but the maximum yield is in the 

 eighth or tenth year. The processes of heating, airing, press- 

 ing, rolling, and drying are continued alternately till the de- 

 sired changes take place in the leaves. The rapidity of this 

 operation and the age of the leaves when picked determine the 

 quality of the tea ; young leaves, quickly prepared, give the 

 best green teas. Old leaves subjected to a less rapid operation 

 yield the black teas. Among the many constituents found by 

 analysis, may be mentioned carbo-hydrates, albuminoids, tan- 

 nin, caffein, aromatic oil, and mineral substances. Tea (an 

 infusion of the leaves) has been used by the Chinese as an 

 exhilarating beverage for centuries. Recently it has found 

 its way into nearly all countries, and is used almost univer- 

 sally now by rich and poor. 



21. Tobacco, Nicotiana tabacum (Nightshade family) was 

 used by the Indians long before America was discovered by 

 Columbus. In old Indian mounds smoking utensils have 

 been found. It was taken to Spain by De Oviedo in the early 

 part of the sixteenth century, later to Prance by Nicot, and to 

 Germany by Gessler. Although sometimes prohibited by 

 edicts, smoking soon became general all over Europe, passed 

 into other countries, and finally found its way into Australia ; 

 and tobacco unfortunately is now '' used by all civilized nations 

 of the globe." It is a native of South America, but cultivated in 

 many countries, being easily acclimated. The plant grows from 

 three to six feet high, and bears long, broad, soft, hairy leaves. 

 The flowers are terminal, rose-color, and showy. The culture, 

 soil and climate affect the quality of the tobacco very much. 



22. " The most beautiful, the most elegant, the most pre- 

 cious of all trees " is the Caryophyllus aroviaticus, which pro- 

 duces the Cloves of commerce. It is a member of the Pink 

 family, and grows to the height of fortj'^ feet. The trunk is 



