20 UTILITY OF THE [LECT. I. 



verted almost altogether from the vegetable king- 

 dom. Much certainly remains undiscovered of 

 the virtues of plants in effecting the cure of dis- 

 eases, and many excellent and very powerful salu- 

 tary agents belong to that kingdom of nature. 



As civilized men are not stationary beings, but 

 are led by the thirst of gain, ambition, curiosity, 

 or enterprise, to visit every part of the habitable 

 surface of the globe, it is requisite that medical 

 practitioners should be able to generalize, and, 

 in searching for remedies to remove the morbid 

 effects of changes of climate and other contin- 

 gencies on the constitution, to know how to 

 substitute the materials within their reach for 

 those they have been accustomed to employ, but 

 which they cannot in every situation obtain. The 

 question may be reasonably asked, How is Botany 

 to teach this knowledge? Let us examine how 

 far we can satisfactorily answer it. Do we, in the 

 first place, wish to ascertain which plants are poi- 

 sonous or salutary? Botany teaches us that all 

 those arranged in the family denominated Cruci- 

 ferce, in that of the Rosacece, and in those of the 

 Malvaceae, Labiatce, and almost all the Cerealia, 

 contain no poisonous species; that the Mushroom 

 tribe, the Solanece, the Apocynece, the Tithymalce, 

 the Ranunculacece, and the Papaverce, are almost 

 all suspicious: and that the Umbellif'erce, the Ari> 

 the Polygons, contain acrid and several deleterious 



3 



