652  Review  of  Advances  in  Pharmacy.  {A^J°ber  ^kT" 
asset.  "  Lest  we  forget "  let  us  bear  in  mind  the  terrible  time  of  the 
"  flu  "  last  year. 
Rapp's  Method  for  the  Estimation  of  Alkaloids. — It  is  claimed 
that  this  method  gives  very  satisfactory  results,  but  it  is.  necessary 
that  the  amount  of  plaster  of  Paris  added  should  be  just  sufficient  to 
prevent  the  mixture  from  hardening,  in  fact  a  soft  paste-like  mix- 
ture answers  very  well.  A  preliminary  blank  trial  with  the  plaster 
to  be  used  is  desirable.  In  the  original  method  it  is  desirable  to 
make  sure  by  an  extra  shaking  with  10  mils  of  chloroform  that  all 
the  alkaloid  has  been  extracted  from  the  mass.  Uncertainty  may 
be  avoided  by  dissolving  the  alkaloid  first  with  chloroform  before 
the  addition  of  the  plaster  and  then  proceeding  with  an  aliquot  por- 
tion of  the  filtered  extract  for  the  estimation.  As  an  example,  in  the 
determination  of  cinchona  bark,  the  substance  is  treated  with  the 
quantity  of  liquid  advised  by  Rapp  and  then  agitated  in  the  same 
flask  with  50  mils  of  chloroform,  made  alkaline,  and  shaken  with  25 
grams  of  plaster  of  Paris.  The  chloroform  is  then  filtered  off  and 
the  filtrate  shaken  with  tenth-normal  acid.  The  plaster  paste  in  this 
case  may  be  of  any  degree  of  stiffness,  as  it  does  not  have  to  be 
washed  out,  all  the  alkaloid  having  been  dissolved  by  the  chloroform 
previous  to  the  addition  of  the  plaster.  In  view  of  the  excellent  re- 
sults obtained  it  is  suggested  that  the  principle  of  Rapp's  method  be 
applied  to  other  extraction  operations  besides  those  with  alkaloids, 
as  the  use  of  plaster  has  a  clarifying  effect  and  assists  the  separation 
of  the  extract. — 7.  Pharm.  Chim.,  1919,  19,  295,  through  The  An- 
alyst, July,  1919,  page  236. 
Iodine  Value  (Wijs)  of  Palm  Kernel  Oil. — The  normal  range  of 
iodine  values  for  palm  kernel  oil  is  16  to  23.  The  average  value  for 
574  samples  of  refined  oil  was  found  to  be  18.1,  and  for  1,236  sam- 
ples of  crude  oil  18.6.  The  oils  worked  with  in  this  investigation 
were  expressed  from  the  kernels  crushed  in  the  mill  under  ordinary 
works  conditions. — /.  Soc.  Chem.  Ind.,  1919,  38,  128,  thruogh  The 
Analyst,  July,  1919,  page  237. 
Analysis  of  Prune  Kernels. — Prune  kernels  gave  a  yield  of  42 
per  cent,  of  oil,  2.47  per  cent,  of  nitrogen,  and  37.42  per  cent,  of 
sugars.  When  cooled  to  50  C.  the  oil  partially  solidified,  the  solid 
portion  being  about  one  third  of  the  whole  amount.   The  sp.  gr.  of 
