PBEFACE. 



Fob many years medical botany lias had no place in most Ameri- 

 can medical schools; and no text-book on the subject has issued from 

 the American press during a generation. 



As a result of this neglect, I believe that vegetable materia mediea 

 is taught at a great disadvantage, and often imperfectly. Plants bear 

 lelations to each other no less definite than those of the chemical com- 

 pounds of inorganic substances ; and a knowledge of these relations 

 should, in my opinion, precede all attempts at classilication of plants 

 as therapeutic agents. 



furthermore, much of the credulity evinced regarding so-called 

 new reined ies of vegetable origin is directly traceable to ignoi-ance of 

 plantb in general, and of their relations to each otlicr. Let the most 

 extravagant assertions be made concerning the therapeutic activity of 

 any hitherto unused ])lant — or of one used and long- forgotten — and ex- 

 perimenters immediately busy themselves Avith it, no matter if other 

 closely allied species arc known to be inert. And yet, the different 

 species of a genua are so closely related that when one is demonstrably 

 useless, as a rule, wc need not expect much from the others. 



As a teacher of medical botany I have been much embarrassed by 

 the want of a text-book suited to the needs of American students — one 

 combining a brief sketch of general botany Mith descriptions of medi- 

 cinal plants — and, in this volume, have endeavored to supply that want. 



In the first part, or Elements of Botany, I have sketched the life- 

 history of plants from germination to reproduction, explaining the 

 technical terms commonly employed in botanical descriptions and the 

 plan of classification in general use at the present day. 



