PREFACE. XVII 



lift of medicines, to all of which they arc 

 ftrangers even in appearance, poffeffing no 

 other knowledge of the very articles fpecified 

 but what they have acquired from books and 

 prefcriptions, Icng fince become obfolete and 

 ufelefs from their inefRcacy? Can they be ex- 

 pected to underftand the chemical pri^ceffes of 

 mercury^ antimony, and other dangerous medi- 

 cines they conftantly put into ufe, without 

 knowing their origins, preparations, combina- 

 tion of principles, or the exact line of diftinc- 

 tion that renders them fahtary remedies or 

 powerful poifons? 



It is alfo highly neceflary to introduce a 

 matter perfedly applicable to the fubjeft of in- 

 veftigation, as an impofition very little known 

 (except to the facuhy); and is a palpable dif- 

 grace to that body, of which every profeflbr of 

 medicine conftitutes a member. It is the com- 

 mon and fcandalous adulteration of drugs, a 

 praftice too prevalent amongft the druggijis in 

 the metropolis y as well as the country; who, 

 from the predominant paffion of gain, fo curi- 

 ouily adulterate, as to deceive even thofe who 

 coniider thcmfelves adepts in deception. And 

 this, to be the better enabled to underfel their 



competitors. 



