Am'ju°i^i9c»arm'}    Recent  Literature  Relating  to  Pharmacy.  345 
ASSAY  OF  BISMUTH  SALICYLATE. 
W.  Kollo  [Ph.  Post,  1899,  2)  has  applied  Thorn's  method  (See  A. 
J.  P.,  1899)  of  bismuth  estimation  to  the  salicylate,  with  satisfactory 
results,  using  for  control  experiment  the  extraction  of  the  salicylic 
acid  from  the  substance;  as  well  as  the  separated  weight  of  the  bis- 
muth oxide.  He  calls  attention  to  an  error  in  the  usual  directions  of 
manufacture  of  the  salicylate — that  the  precipitated  salt  be  washed 
with  water  until  the  filtrate  no  longer  gives  a  reaction  with  ferric 
chloride.  This  direction  is,  of  course,  intended  to  totally  remove 
the  free  salicylic  acid  ;  but  as  traces  of  bismuth  salicylate  dissolve 
in  the  wash- water,  it  always  gives  the  reaction  with  iron.  He  amends 
the  directions  to  read  that  the  ethereal  extract  of  the  last  washings 
should  not  show  the  ferric  chloride  reaction.  H.  V.  A. 
INDIRECT  QUANTITATIVE  ESTIMATION  OF  ALKALINE  EARTHS. 
Noting  the  difficulty  in  the  quantitative  separation  of  calcium, 
strontium  and  barium,  Knoblauch  (Ph.  Zeit.,  1898,922)  devised  a 
simple  indirect  method  of  estimation  of  any  two  ot  these  elements 
based  on  the  molecular  weights  of  their  oxides  and  carbonates. 
The  process,  briefly  outlined,  consists  in  the  precipitation  of  the 
mixed  elements  as  carbonates,  and  the  conversion  of  these  by  heat- 
ing with  a  given  weight  of  borax  glass.  The  weight  of  the  mixed 
carbonates  is  the  factor  p  ;  that  of  the  oxides,  the  factor  n,  and  the 
differential  equations  are  as  follows  : 
Calcium  and  barium  : 
CaO  — :  2-00652915  p  —  2-58283141  n. 
BaO  =  n  —  CaO. 
Calcium  and  strontium  : 
CaO  =  27736936  p  — 3-95263432  n.    SrO  =  n  —  CaO. 
Barium  and  strontium  : 
SrO  =  7-25463260  p  —  9-33816773  n.    BaO  ==  n — SrO. 
As  the  matter  is  of  analytical  rather  than  pharmaceutical  interest, 
the  reader  is  referred  to  the  original  for  details,  as  well  as  for  the 
author's  method  of  estimation,  when  all  three  elements  are  present. 
H.  V.  A. 
BISMUTUM  OR  BIMUSTHUM  ? 
In  defense  of  the  orthography  of  the  German  pharmacopceial  term 
bismutum,  T.  Husemann  (Ph.  Zeit.,  1898,  895)  gives  a  highly  inter- 
