46      PURITY  OF  SULPHATE  OF  QUININE  OF  COMMERCE. 
quinidine.  One  hundred  grains  of  this  salt  contain  71-68  of 
pure  quinidine.  To  the  filtered  solution  again  add  hydrate  of 
soda  till  decidedly  alkaline,  when  the  cinchonine  and  cinchoni- 
dine  will  be  precipitated  if  present. 
It  was  according  to  the  above-mentioned  process  that  the  fol- 
lowing samples  of  quinine  were  analyzed.  The  first  was  taken 
from  a  four-ounce  bottle  from  Messrs,  Howard's  and  Sons, 
Stratford. 
On  submitting  it  to  the  soda  and  ether  test  there  was  no  ap- 
pearance of  cinchonine,  but  beneath  the  ether  was  an  oily  sub- 
stratum, which  by  the  usual  tests  was  proved  to  be  quinidine. 
The  quantitative  analysis  showed  this  to  amount  to  2-8  per 
cent.  After  the  separation  of  the  quinidine  the  soda  gave  no 
precipitate,  proving  the  absence  of  cinchonine  and  cinchonidine 
Consequently  this  was  an  extremely  pure  sample  of  sulphate  of 
quinine. 
The  next  sample  tested  was  quinine  from  the  laboratory  of 
De  Lisle  and  Co.,  Paris,  better  known  as  "  Pelletier's  quinine." 
This  yielded  4-1  per  cent,  of  quinidine,  and  the  soda  gave  a 
trace  of  cinchonine. 
The  third  sample  was  from  the  chemical  works  of  Mr.  Jacob 
Hulle,  Lombard  Road,  Batter3ea.  This  contained  5-6  per 
cent,  of  quinidine  and  «8  per  cent,  of  cinchonine  and  cinchoni- 
dine. 
The  unbleached  variety  of  the  same  maker  was,  as  may  be 
expected,  much  less  pure  than  any  of  the  above. 
The  sample  examined  contained  16*3  per  cent,  of  quinidine 
and  4-2  per  cent,  of  cinchonine  and  cinchonidine.  All^hese 
were  taken  out  of  bottles  unopened  and  sealed  by  the  manufac- 
turer. 
With  neither  was  there  any  precipitate  with  nitrate  of  silver 
and  nitric  acid,  proving  the  absence  of  muriate  of  cinchonine  ; 
neither  did  strong  sulphuric  acid  produce  any  tinge  except  the 
usual  pale  yellow  tint. 
A  quinine  has  lately  been  introduced  by  Messrs.  Herring  and 
Co.,  Aldersgate  Street,  under  the  name  of  "semicrystallized 
quinine,"  but  as  it  does  not  profess  to  be  pure  sulphate  of  qui- 
nine, but  a  compound  of  all  the  alkaloids  of  the  yellow  cin- 
chona barks,  it  ought  by  no  means  to  be  used  by  the  dispenser 
