344       Recent  Literature  Relating  to  Pharmacy.  {Am-JJu0iy^imrm- 
Prof.  Clemens  Winkler,  of  Freiburg,  Saxony,  publishes  in  the 
Betichte  der  Deutschcn  Gesellschaft  for  June  nth,  which  is  just 
at  hand,  a  review  of  Fittica's  experiments  and  shows  quite  conclu- 
sively that  the  arsenic  found  is  simply  a  constant  impurity  of  the 
phosphorus,  and,  in  four  experiments,  using  different  oxidizing 
agents,  he  gets  I  91,  1-925,  1-920  and  1-920  per  cent,  of  arsenic. 
This  uniformity,  to  his  mind,  shows  the  exact  extent  of  the  arsenic 
impurity  originally  present  in  the  phosphorus  used.  So  we  still 
have  to  consider  arsenic  as  an  element. 
RECENT  LITERATURE  RELATING  TO  PHARMACY. 
PERIODIDE  SEPARATION  IN  ALKALOIDAL  ASSAY. 
While  Gordon  and  Prescott  suggest  a  volumetric  estimation  of 
alkaloids  through  their  periodides,  Kippenberger  (Ap.  Ztit.y  through 
Ph.  Cent.,  1898,  903)  has  devised  an  assay  wherein  the  alkaloids  are 
separated  as  periodides  and  weighed  free.  His  method  is  as  fol- 
lows:  The  preparation,  freed  from  alcohol,  is  treated  with  an  iodine 
solution  (20  grammes  iodine  and  60  grammes  potassium  iodide  to 
the  litre),  and  the  precipitate  collected  on  a  filter.  This  is  washed 
with  water  (best  containing  a  little  sodium  chloride,  to  avoid  loss 
of  the  slightly  soluble  periodide),  after  which  the  precipitate  is 
extracted  with  rectified  acetone,  the  filtrate  dropping  into  a  funnel 
and  repeatedly  poured  back  over  the  precipitate. 
The  acetone  solution  of  the  periodide  is  shaken  with  an  alkaline 
hydrate  solution  (which  takes  up  the  iodine),  and  then  free  hydro, 
chloric  acid  is  added  in  excess,  and  finally  water  is  added.  The 
mixed  liquid  is  then  shaken  with  petroleum  ether,  which  extracts 
coloring  matter,  last  traces  of  iodine  and  a  large  part  of  the  ace- 
tone,  and  this  mixture  is  separated  from  the  aqueous  layer,  which 
is  then  freed  from  the  remaining  acetone  by  heating  on  a  water- 
bath.  Thereupon  it  is  returned  to  the  separatory  funnel,  diluted 
with  water  and  made  alkaline,  and  the  free  alkaloid  extracted  with 
chloroform. 
The  author  claims  that  this  method,  which  appears  complicated 
and  subject  to  error,  gives  good  results.  The  article  gives  special 
directions  for  the  preparation  of  each  drug,  for  which  the  reader  is 
referred  to  the  original.  H.  V.  A. 
