12 
PRACTICAL  KNOWLEDGE. 
tractive  matter  in  the  fly,  as  is  likewise  the  case  with  many  other 
organic  principles.    Hence  it  is  that  though  ether  is  a  ready 
solvent  for  eantharidin  and  alcohol  is  not,  the  latter  is  a  good 
menstruum  for  cantharides. 
Philadelphia,  Oct,  1859. 
PRACTICAL  KNOWLEDGE. 
By  James  W.  Mill. 
Pharmacy  is  defined  to  be  "  the  art  of  preparing  and  dis- 
pensing medicines."  It  is,  therefore,  the  duty  of  its  practitioner 
— the  apothecary — to  prepare  the  medicines  which  he  dispenses. 
The  faithful  discharge  of  this  duty  would  seem  to  demand  that 
the  apothecary  himself  should  make  all  the  medicinal  prepara- 
tions required  in  his  business.  This,  however,  in  the  present 
advanced  state  of  the  art,  is  impracticable,  since  it  would  re- 
quire not  only  more  time  than  the  apothecary  could  well  spare 
from  his  other  duties,  but  would  also  involve  a  much  larger  ex- 
penditure for  apparatus  than  the  circumstances  of  the  case 
would  warrant. 
There  are,  nevertheless,  a  great  many  preparations,  the 
manufacture  of  which  does  not  need  the  aid  of  costly  apparatus, 
and  these  the  apothecary  can,  and  the  writer  believes  should, 
make  for  himself,  for  example,  the  solution  and  acetate  of  pot- 
assa ;  citrate  and  ammonia-citrate  of  iron  ;  citrate  of  iron  and 
quinia  ;  tartrate  of  iron  and  potassa,  and  such  like.  The  writer 
believes  also  that  under  the  guidance  of  authoritative  formula, 
the  skilful  apothecary  could  make  his  own  fluid  extracts,  which 
would,  doubtless,  be  much  more  faithful  representations  of  their 
respective  drugs,  than  many  of  those  now  furnished  by  the 
manufacturing  pharmaceutist.  The  recent  very  valuable  re- 
port on  Fluid  Extracts,  by  Prof.  Procter,  at  the  last  meeting  of 
the  American  Pharmaceutical  Association,  and  the  near  approach 
of  a  new  edition  of  the  Pharmacopoeia,  give  promise,  that  he 
will  not  long  be  without  an  authoritative  guide  in  the  manufac- 
ture of  this  most  important  class  of  medicinal  preparations. 
This  is  preeminently  an  age  of  pharmaceutical  progress,  and 
the  apothecary  who  would  maintain  a  respectable  position  in  the 
ranks,  must  not  only  not  forget  what  he  has  already  learned, 
