474  Tlie  AsJi  Content  of  DniQs,  fAm  jour.  I'h&rm, 
'  ^  '  1     Oftolier,  1911. 
The  finished  tincture,  that  is  the  mixture  of  the  two  halves,  was 
found  to  be  more  actively  vesicant  than  the  U.S. P.  tincture. 
It  is  probable  that  the  acid  added  to  the  first  part  of  the  men- 
struum was  insufficient  in  amount,  or  that,  for  some  other  reason, 
some  of  the  combined  cantharidin  failed  to  be  liberated.  This  point 
should  have  further  investigation.  But  it  is  very  evident  from  the 
way  in  which  extraction  proceeded  that  acetone  is  a  much  better 
solvent  for  extracting  cantharides  than  alcohol,  and  if  used  there 
would  be  practically  no  difficulty  in  making  a  full  strength  tincture. 
Some  suitable  acid  should,  however,  be  added  to  that  part  of  the 
menstruum  used  for  moistening  and  macerating  the  drug  in  such 
proportion  as  to  insure  the  liberation  of  all  combined  cantharidin. 
To  summarize,  cantharides  can  be  exhausted  by  gently  heating 
with  a  solution  of  a  caustic  alkali  to  convert  the  cantharidin  into 
cantharidate,  drying,  grinding  and  extracting  with  dilute  alcohol. 
The  resulting  preparation,  however,  is  weak  in  vesicating  power. 
Exhaustion  can  also  be  accomplished  by  liberating  any  combined 
cantharidin  present  in  the  drug  by  means  of  a  suitable  acid  and 
then  extracting  with  acetone.  The  resulting  preparation  is  actively 
vesicant. 
Laboratory  Eli  Lilly  &  Co.,  Indianapolis,  Ind. 
THE  ASH  CONTENT  OF  DRUGS.^ 
By  M.  I.  Wn.BERT,  Washington,  D.  C. 
In  recent  years  there  has  been  evidenced  a  growing  disposition 
to  place  considerable  reliance  on  the  ash  content  of  drugs  as  an 
aid  in  determining  the  nature  and  purity  of  the  product  under 
examination. 
With  a  view  of  ascertaining  what  if  any  uniformity  exists  in  the 
permissible  ash  content  of  official  drugs,  an  analysis  of  the  require- 
ments made  in  ten  of  the  recently  published  pharmacopoeias  was 
made  and  the  maximum  ash  content  of  some  of  the  more  widely  used 
drugs  is  herewith  presented  in  the  form  of  a  table. 
Restricting  the  permissible  quantity  of  ash  in  connection  with 
vegetable  or  crude  drugs  is  a  comparatively  modern  requirement. 
It  was  introduced  in  the  second  edition  of  the  German  Pharmacopoeia, 
^Read  at  the  Boston  meeting  of  the  American  Pharmaceutical  Associa- 
tion, August,  191 1. 
