fNTRODUCTlON. 



The Pharmacopeia contains Instructions for 

 compounding or mixinjr those simple medicines 

 and preparations in such a v/ay, that they may 

 mutualiy assist each other in their CiiAti\e opera- 

 tion ; and sometimes produce effect** that cannot 

 be obtained from either of them individually. 

 Many of those persons who undertake to com- 

 pound horse medicine, are unacquainted with che- 

 mistry, and not aware, that by improper mixtures, 

 the original qualities of the ingredients may b3 

 destroyed ; thus, by mixing vitriolic acid, or oil 

 of vitriol, with pure soda, both of which are 

 powerful caustics, we produce that innocent com- 

 j)Ound, termed Glauber's salt. Mistakes of this 

 kind are very common in books of farriery, which 

 -therefore can seldom be depended upon. 



Another very common error in those books, a§ 

 well as in the recipes of farriers in general, is, 

 that instead of mixing medicines that are similar in 

 their nature, and capable of co-operating in the 

 removal of diseases, they frequently direct the 

 most heteroi^eneous mixtures, uniting medicines of 

 •opposite qualities in the same ball or drtnclu 



In our Pharmacopoeia we have endeavoured to 

 avoid those errors ; the compounds are directed 

 according to the principles of chemistry ; and such 

 only are recommended ai hnve been found effica- 

 cious in practice. 



