Am"oc°tu,ril6arm'}      Guarana.    Methods  for  its  Assay.  483 
GUAKANA,  METHODS  FOR  ITS  ASSAY,  AND  THE 
ASSAY  OF  ITS  FLUID  EXTRACT.1 
By  H.  W.  Snow,  Ph.C 
In  the  Amer.  Jour,  of  Phar.,  1875,  p.  135  is  a  method,  proposed 
by  E.  S.  Wayne,  for  the  extraction  of  caffeine  from  tea  and  coffee, 
with  the  remark  that  it  yielded  very  high  results  of  a  pure  white 
alkaloid.  Later  on,  F.  V.  Greene  (Amer.  Jour.  Phar.,  1877, p.  337) 
applied  the  process  to  guarana,  as  a  method  of  assay.  J.  H.  Feem- 
ster  (Proc.  A.  P.  A.  xxx./p.  569)  more  recently,  has  also  recommended 
this  method  as  a  practicable  assay  process,  and  suited  for  pharmaceu- 
tical purposes.  The  criticism  which  the  writer  would  offer  upon  it  is 
ohiefly  the  length  of  time  required  to  complete  the  operation,  but 
also  as  compared  with  the  process  to  follow  gives  lower  results  indi- 
cating a  less  perfect  exhaustion  of  the  drug.  In  the  boiling  with 
litharge,  several  hours  are  consumed,  which  followed  by  filtration, 
washing,  removing  the  lead,  etc.,  extends  the  examination  over  the 
greater  part  of  two  days,  and  occasionally  longer,  and  requiring  con- 
siderable attention  during  the  whole  of  that  time.  Any  process  then 
which  can  be  begun  late  in  the  afternoon  of  one  day,  and  finished 
easily  in  four  or  five  hours  the  next  day,  would,  all  other  things 
being  equal,  recommend  itself  to  all  who  are  engaged  in  making  a 
number  of  pharmaceutical  assays  each  day,  but  particularly  would  it 
be  desirable  when  along  with  rapidity,  we  get  a  more  perfect  exhaus- 
tion of  the  drug.  The  process  which  the  writer  has  to  suggest  is  not 
new,  except  in  its  application  to  this  drug,  being  the  same  as  that 
proposed  by  A.  B.  Lyons,  for  the  assay  of  nux  vomica  (Drug.  Cir. 
1886,  p.  137)  and  which  as  applied  to  this  drug  is  briefly  described  as 
follows : 
Place  five  grammes  of  the  drug  in  a  small  flask  holding  about  100 
cc.  or  120  cc,  introduce  44  cc.  of  chloroform,  cork  and  shake,  then 
add  6  cc.  of  a  mixture  of  alcohol,  6  volumes,  and  stronger  water  of 
ammonia  1  volume,  again  shake  vigorously,  and  set  aside  with  fre- 
quent shaking  during  several  hours  or  allow  to  stand  over  night. 
Then  filter  rapidly  through  a  small  dry  filter  paper,  four  inches  in 
diameter,  and  receiving  the  filtrate  in  a  vessel  graduated  to  40  cc. 
(corresponding  to  4  grammes  of  drug),  evaporate  the  chloroform  and 
treat  the  residue  with  a  little  water  and  filter  through  cotton,  after- 
presented  to  the  Amer.  Pharm.  Assoc.,  in  Providence,  September,  1886. 
