LKCT. I.] SCIENCE OF BOTANY. 21 



species. It also informs us, that some plants are 

 acrid and poisonous when growing in water, which 

 appears to be their natural element, although they 

 are inert when they vegetate on dry land; and 

 that some inert land plants become acrid when 

 they accidentally spring up in water or in marshy 

 places. Do we wish to discover the probable me- 

 dicinal properties of the plants in any new situa- 

 tion, before we venture to try their effects upon 

 the animal frame? Botany informs us how to do 

 so, by arranging the plants with which we are un- 

 acquainted, into their natural families. Thus we 

 know that the Solanece are narcotic ; the Gentiance 

 yield a bitter, and sometimes a purgative principle; 

 the Laurel tribe a stimulant, which is in some in- 

 stances highly deleterious; the Gorymbiferce are 

 emmenagogue; the Rubiacea?, to which Cinchona 

 belongs, diuretic and tonic; the Crucif'erce antiscor- 

 butic; and the Malvaceae emollient. A medical Bo- 

 tanist, believing that a certain plant yields a pecu- 

 liar medicinal principle, is led to examine whether 

 the species of the same genus which are indigenous 

 to the clime that he inhabits may not contain some- 

 thing similar, if not exactly the same ; and thence 

 discoveries valuable to his country, and sometimes 

 to the human race, are effected. But this import- 

 ant method of generalizing can be practised only 

 by the Botanist; for, to one ignorant of Botany, 

 not only is the language foreign and unintelligible, 



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