116 
PHARMACEUTICAL  NOTICES. 
adopt  the  proportions  of  the  Dublin  Pharmacopoeia,  which 
directs  about  22  grains  of  the  extract  to  the  fluid-ounce.  But  I 
apprehend  that  very  few  of  them  have  adverted  to  the  circum- 
stance, that  the  Dublin  formula  prescribes  the  "purified  extract." 
The  best  commercial  Ext.  Cannabis  2nd.  appears  to  vary 
considerably  in  purity;  hence  the  propriety,  and  indeed  the 
necessity,  of  the  precaution  enjoined  in  the  Dublin  Pharmaco- 
poeia, to  purify  the  extract  previously  to  weighing  it  for  solution 
in  making  the  tincture.  I  have  found  that  in  one  instance  the 
London-made  extract  (from  one  of  the  first  houses  of  that  city) 
contained  about  40  per  cent,  of  matter  insoluble  in  alcohol ;  so 
that  if,  (as  I  believe  is  generally  the  case,)  the  tincture  is  made 
from  commercial  extract,  it  contains  sometimes  not  much  more 
than  13  grains  of  pure  extract  to  the  ounce,  instead  of  22 
grains,  as  intended  by  the  Dublin  Pharmacopoeia.  This  circum- 
stance may  perhaps  account  for  the  frequent  complaints  of 
physicians,  of  disappointment  in  the  use  of  the  Tincture  of  Indian 
Hemp.  The  cost  of  the  article,  in  consequence  of  making  it 
with  the  purified  extract,  is,  of  course,  nearly  double  what  it 
would  otherwise  be ;  but  this  ought  to  be  of  no  moment,  com- 
pared with  the  importance  of  supplying  a  reliable  article. 
Lactucarium  purificatum. — It  is  well  known  to  pharmaceutists 
that  great  difficulty  occurs  in  attempting  to  pulverize  lactuca- 
rium, or  to  mix  it  uniformly  with  other  substances,  either  solid 
or  liquid,  in  compounding  prescriptions.  Rubbed  into  a  mix- 
ture, even  with  extreme  care  and  labor,  its  coarseness  is  such  as 
to  be  very  disagreeable  to  the  patient,  and  to  look  like  clumsy 
manipulation  on  the  part  of  the  druggist.  This  results  from  a 
certain  degree  of  toughness,  which  renders  it  almost  unmanage- 
able, and  is  occasioned  apparently  by  that  portion  of  it  which  has 
been  considered  by  some  as  allied  to  caoutchouc,  and  by  others 
as  rather  of  a  waxy  nature.  This  substance  appears  to  inter- 
fere also  with  its  efficacy  as  a  narcotic  or  sedative,  involving  its 
particles,  as  it  were,  in  a  coat  of  insoluble  matter.  I  have  en- 
deavored to  remedy  this  inconvenience  by  thoroughly  washing 
the  lactucarium  with  chloroform,  which  abstracts  from  it  two 
ingredients,  viz.,  the  above  mentioned  caoutchouc-like  matter, 
and  a  very  white,  imperfectly  crystalline  or  granular  substance, 
