Amjune?i895arm*}  An  Examination  of  Commercial  Fluid  Extracts.  295 
The  process  recommended  in  Dragendorff's  Plant  Analysis,  pre- 
cipitation with  basic  lead  acetate,  and  subsequent  treatment  with 
sulphuric  acid,  was  employed. 
Ten  c.c.  of  the  fluid  extract  under  examination  was  diluted  with 
water  to  20  c.c. 
In  most  cases  the  mixture  became  cloudy,  and  filtration,  until  a 
clear  liquid  was  obtained,  was  necessary. 
The  mixture  was  then  precipitated  with  basic  lead  acetate  solu- 
tion, filtered  from  the  precipitate  and  the  excess  of  lead  in  the  fil- 
trate carefully  precipitated  by  diluted  sulphuric  acid. 
The  liquid,  by  means  of  washing  the  precipitate  with  water,  was 
made  up  to  the  original  volume  of  20  c.c. 
As  a  rule  the  effect  of  picric  acid  test  solution  upon  the  liquid 
representing  50  per  cent,  of  the  fluid  extract,  was  first  noted,  and 
also  a  superficial  examination  for  glucose  made  by  means  of  the 
picric  acid  and  potash  method  of  Braun  with  the  intention  of 
determining  the  necessary  degree  of  dilution  before  making  the 
volumetric  examination  with  Fehling's  solution 
A  few  statements  must  be  made  regarding  fluid  extracts  in  gen- 
eral, before  quoting  the  results  obtained.  In  samples  containing 
caramel,  if  the  same  is  present  in  considerable  amount,  the  filtrate, 
after  the  lead  and  acid  treatment,  is  of  a  brown  color. 
Caramel  is  not  precipitated  by  basic  lead  acetate,  and  through 
this  fact  evidence  of  its  presence  was  shown  in  a  number  of  fluid 
extracts. 
For  instance,  in  a  sample  of  F.  E.  Taraxacum,  prepared  by  the 
writer  according  to  the  Pharmacopoeia,  the  final  filtrate,  after  this 
treatment,  was  almost  colorless,  while  in  several  commercial  speci- 
mens, similarly  treated,  the  same  was  decidedly  brown.  A  like 
observation  was  also  made  with  F.  E.  Gentian  and  several  others. 
The  preparations  examined  by  the  writer  comprised  the  products 
of  eight  different  manufacturing  firms,  the  samples  all  being  selected 
at  random,  preferring,  however,  those  official,  wherever  obtainable. 
The  amount  of  glucose,  or,  perhaps,  more  appropriately,  the 
substance  which  reduces  Fehling's  solution  and  gives  reactions  with 
other  glucose  reagents,  varied  considerably,  some  extracts  showing 
a  high  percentage,  while  others  only  contained  scarcely  appreciable 
traces.  Due  to  lack  of  time,  the  percentage  was  not  ascertained  in 
some,  while  in  a  number  several  determinations  were  made. 
