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ELEMENTS OF BOTANY. 



I INTliODUCTIOX. 



Botany is the science which treats of the vegetable kirifi^doin. 

 A science so comprehensive, iuchiding everything which relates to 

 plants, from the life liistory of those low organisms on the border Hue 

 between the animal and the vegetable world to that of the giant oak which 

 endures for centuries, must of necessity be divided for the convenience 

 of students. Accordingly general botany comprises many well-recognized 

 departments, one of which, devoted to the history of medicinal plants, is 

 , known as medical botany. 



But medical botany is also a comin'ehensive science, for the list of 

 plants possessing greater or less medicinal activity is long, and the plants 

 are, in many instances, so remote and inaccessible that their study is 

 beset with many difricultios. The obstacles, however, in the way of the 

 student who would acquire a knowledge of tlie medicinal plants of his 

 own country are neither numerous nor formidable. Especially is this true 

 of the medical botan}' of North America ; for tnough this continent, with its 

 broad extent of territory, varied surface, and extremes of temperature, sup- 

 ■ ■ ports an extensive and interesting flora, the number of medicinal species is 

 surprisingly small, and these are so distributed as to be generally accessible. 

 The medical botany of North America, then, treats of all plants grow- 

 ing on the continent without cultivation which possess, or are supposed 

 I to possess, medicinal activity. It treats of them as living, organized 

 I bodies, classifying them according to their structural affinities, and not as 

 I they are treated of in the Materia Medica, as mere drugs, arranged ac- 

 I cording to their real or supposed therapeutic effects. 



-I It will be seen, liowever, that this classiflcation of plants according to 

 . their structural affinities may often afford valuable hints as to the thera- 

 peutic properties of alhed species. As the comparative anatomist and 

 __ physiologist, kno:\ing the structure and habits of a single animal of a 

 family, may deduce the habits of an allied species whose structure only is 

 known, so may the medical botanist, knowing the physiological or thera- 

 peutic effect of a single species of a genus, draAv a reasonable inference re- 

 garding the properties of an alhed species iu advance of expeiimentation. 



