ON  THE  UNCERTAINTY  OF  PHARMACEUTICAL  PREPARATIONS.  155 
sons  in  ordinary  mercantile  pursuits  may  judge  sufficiently  of  the 
quality  of  many  articles  of  merchandize  from  mere  superficial  ex- 
aminations ;  but  not  so  with  drugs  and  medicines. 
Who  is  there  that  can  say,  from  a  casual  inspection,  whether 
the  Iodide  of  Potassium  of  commerce  does  or  does  not  contain  from 
ten,  fifteen  or  twenty  per  cent,  of  impurities,  or  that  the  Sulphate 
of  Quinine  has  not  been  adulterated  by  the  admixture  of  Salicine, 
Mannite,  &c;  or  that  the  powdered  Cinchona  bark  is  or  is  not 
mixed  with  the  powdered  Maricaibo  or  Carthagena  barks  ;  or, 
lastly,  that  the  powdered  Rhubarb  has  not  been  made  from  black, 
rotten  and  wormeaten  roots,  those  which  were  wholly  unsaleable 
in  the  crude  state,  and  which  were  colored  and  mixed  with  foreign 
material,  so  as  to  appear  of  the  first  quality  ?  Then  how  are 
physicians  to  judge  of  their  qualities  when,  even  if  they  had  the 
time  to  spare  from  their  professional  labors,  they  have  not  the 
necessary  apparatus  for  such  investigations  1 
In  our  solicitude  for  obtaining  articles  of  the  best  quality  from 
foreign  countries,  the  importance  of  having  the  pharmaceutical 
preparations  of  home  manufacture  equally  as  good,  should  not  be 
overlooked.  We  have  no  guaranty  of  their  being  properly  pre- 
pared, both  as  to  the  proportions  and  quality  of  the  articles  used 
in  their  composition,  but  the  integrity  and  competency  of  the  manu- 
facturer. 
We  have  a  Pharmacopoeia,  promulgated  by  a  National  Medical 
Convention,  which  meets  every  ten  years  at  the  City  of  Washing- 
ton, for  the  purpose  of  making  such  alterations  and  additions  as 
may  be  found  necessary  from  experience  ;  and  this  work  should  be 
the  guide  of  every  apothecary,  and  physicians  should  in  all  cases 
conform  their  prescriptions  to  it  as  far  as  practicable.  In  follow- 
ing it  strictly  no  physician  or  apothecary  can  carry  out  the  direc- 
tions unless  he  is  in  possession  of  the  right  weights  and  measures. 
The  troy,  or  apothecary  weights,  and  the  wine  gallon  and  its  sub- 
divisions, are  absolutely  requisite  in  compounding,  and  should  al- 
ways be  used,  except  when  special  mention  is  made  to  the  con- 
trary. 
An  instance  or  two  may  show  more  clearly  what  we  are  en- 
deavoring to  impress  upon  the  minds  of  physicians.  For  instance, 
in  the  preparation  of  the  Tincture  of  Opium,  the  directions  are  to 
take  of  Opium,  in  powder,  two  ounces  and  a  half ;  of  Diluted  Alco- 
