AND ANIMAL LIFE. 



CHAP. XVIII. 



The general action of Emetics on the system, with 

 a Jew remarks on their efficacy in Chronic and 

 Acute Diseases. 



DXV. THERE are few classes of medicines 

 that have been so universally employed as that 

 of emetics. From the earliest authentic records 

 of medical science to the present day these sub- 

 stances have been used, and occasionally extolled 

 as specifics in a variety of diseases. It is impos- 

 sible to deny the good effects which have been 

 attributed to them ; and it is not difficult to ac- 

 count for their success and general adoption at 

 one time, or for their injurious tendency and par- 

 tial reception at another. 



DXVI. When our knowledge of the opera- 

 tion of medicines is narrow or inaccurate, or when 

 we are, in a great measure, ignorant of certain 

 important laws of the animal economy, our prac- 

 tice is necessarily empirical. If, at one time, we 

 have cured diseases of a certain class by emetics, 

 at another we immediately prescribe the same, 

 whenever the same or similar indications are pre- 

 sent, without being fully sensible that the means 

 which we had previously found beneficial were 

 complex in their nature, and that the affections 

 which we had to treat were also as multifarious 



