PREFACE. 



say that there are not hundreds of equally powerful reme- 

 dies still remaining to be discovered. Look to Hemi- 

 desmus indicus, the source of Indian Sarsaparilla, the 

 most active medicine of that name now known to the 

 English physician, although excluded from the Pharma- 

 copoeia ; to Chloranthus officinalis, unrivalled in Java for 

 its aromatic properties and powerful stimulating effects ; to 

 Soymida febrifuga, Galipea officinalis, and Cedrela Toona, 

 which, at least, rival the Jesuit's bark in their influence over 

 the most dangerous fevers ; to Ery throxylon Coca one of the 

 most active stimulants of the nervous system; or, finally, 

 consider the accounts we have of the effects of Jamaica 

 Dogwood, Piscidia Erythrina, which, if there is any truth 

 in medical reports, must be a narcotic superior to opium 

 for many purposes ; and it must be sufficiently apparent 

 to all unprejudiced minds, that the resources of the vege- 

 table kingdom, far from being exhausted, have hardly yet 

 been called into existence. It is presumptuous for the 

 theorist to assert that he already possesses a remedy " for 

 all the maladies that flesh is heir to ; " it is mere idleness 

 in the routine practitioner, carried away by the attraction 

 of specious generalities, to fancy that one tonic is as good 

 as another tonic, or one purgative as another purgative. 

 In reality the true cause of the different actions of medi- 

 cines upon the human body is admitted by the highest au- 

 thorities to be wholly unknown ; and surely this is in itself 

 the best of all reasons why we should not assume that we 

 already possess against disease all the remedies which 

 nature affords ; on the contrary, it should stimulate us to 

 reiterated enquiries into the peculiar action of new remedial 

 agents. 



The medical student rarely knows, at the time when he 

 is acquiring his professional education, what his after des- 

 tiny will be. A large proportion of the young men who 

 frequent the class-rooms are scattered to all the corners of 

 the earth ; they are perpetually liable to be cut off from 

 supplies of the drugs of the Pharmacopoeia, and then are 

 driven upon their own resources; and they find the medicines 



viii 



