PREFACE. 



For many years medical botany has 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 medica 

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

 relations 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 classification of plants 

 as therapeutic agents. 



Furthermore, much of the credulity evinced regarding so-called 

 new remedies of vegetable origin is directly traceable to ignorance of 

 plants in general, and of their relations to each other. Let the most 

 extravagant assertions be made concerning the therapeutic activity of 

 any hitherto unused plant — or of one used and long- forgotten — and ex- 

 perimenters immediately busy themselves with it, no matter if other 

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

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

 useless, as a rule, we 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 with 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. 



