Am'ji<iy,r*i9i9arm"  )      Purify  °f  Commercial  Aspirin.  46i 
on  a  somewhat  lower  plane  than  with  the  army  of  the  Great  Re- 
public, where  the  pharmacien  and  mcdecin  are,  in  every  sense  of  the 
term,  "  Brothers  in  Arms." 
M.D.,  L.  P.  S.  I. 
THE  PURITY  OF  COMMERCIAL  ASPIRIN  AND  ASPIRIN 
TABLETS.1 
By  A.  J.  Jones. 
In  the  earlier  stages  of  the  manufacture  in  this  country  of  as- 
pirin, it  was  almost  impossible  to  maintain  a  supply  of  the  product 
of  the  recognized  standard,  such  a  condition  of  affairs  being  what 
is  expected  when  the  inexperience  and  difficulties  attending  a  new 
manufacture  are  taken  into  account.  Some  samples  were  very 
good,  others  graded  down  to  products  that  could  not  be  passed  at 
all,  whilst  frequently  the  purchaser's  only  option  was  to  buy  the 
least  faulty  samples  on  offer  at  the  time.  Many  were  not  of  the 
standard  of  the  British  Pharmacopoeia,  and  the  opinion  was  even 
expressed  that  the  official  standard  was  commercially  impossible. 
The  characters  and  tests  of  the  British  Pharmacopoeia  do  not  admit 
the  question  of  grade,  nor  are  they  sufficient  to  offer  any  help  when 
that  matter  becomes  involved.  In  such  cases  a  more  detailed  ex- 
amination is  necessary,  and  the  present  paper  is  a  note  of  results 
and  observations  made  in  this  direction.  The  samples  are  of  mod- 
erately recent  date,  and,  since  a  much  better  stage  of  stability  in 
the  manufacture  has  now  been  reached,  these  are  fairly  representa- 
tive of  the  current  market. 
Methods  of  Testing. 
The  tests  used  in  the  case  of  the  samples  of  aspirin  in  question 
consist  of  determinations  of  acid,  ester,  and  bromine  values, 
together  with  free  salicylic  acid,  and  melting-point.  For  the  better 
comparison  the  results  are  expressed  in  Cc.  iV/5  per  i  gram  of  sub- 
stance, the  bromine  value  being  reduced  to  terms  of  a  monobasic 
reaction :  that  is  to  say,  one  atom  of  bromine  per  molecule.  Under 
these  conditions  it  is  clear  that  with  true  acetylsalicylic  acid  the 
1  Reprinted  from  The  Chemist  and  Druggist,  April  26,  1919. 
