438 THE LAWS OF ORGANIC 



would be absurd to suppose, that any individual 

 system of the body is exclusively acted upon by 

 the operation of general causes ; but it would not 

 be less absurd to imagine that every function is 

 equally affected by them. The diseases which 

 have been enumerated differ widely in their 

 proximate and remote causes, and they also oc- 

 cupy different textures or organs of the body. 

 Although these circumstances be so dissimilar, 

 yet emetics have been employed in all of them, 

 and with benefit. It is the object of the present 

 chapter to endeavour to explain the principles 

 on which emetics have been or may be useful. 



DXXXVI. The changes in the distribution and 

 quality of 'the blood are conditions common to almost 

 every disease, but those enumerated under this 

 head are a few of such as exhibit these changes to a 

 greater extent than any other ; and I conceive that 

 emetics are useful only in such, as they tend to 

 alter that distribution, or improve the quality of 

 the circulating fluid. That these and subsequent 

 views be properly appreciated, it is necessary that 

 the proximate cause, symptoms, and treatment 

 of each disease be generally understood ; but as 

 these considerations would interfere with the 

 present inquiry, I shall examine them as briefly 

 as possible. 



DXXXVII. Emetics are frequently exhibited 

 at the commencement of contagious or intermit- 

 tent fevers. Few remedies are so powerful in 



