Am'MTa°yriJi9arm'  )  Current  Literature.  313 
very  slightly  soluble.  Whatever  may  be  the  solvent  action  of  codeine 
on  morphine  in  aqueous  solution,  assay  conditions  are  different,  in 
that  sufficient  ether  is  present  to  hold  all  the  codeine  in  solution. 
Annett  and  Singh's  procedure  of  shaking  the  lime  solution  with 
toluene  before  treating  with  ether  and  ammonium  chloride  was 
tried,  using  benzene  in  place  of  toluene,  with  the  resulting  produc- 
tion of  a  frothy  emulsion  which  makes  extraction  troublesome. 
This  emulsion  probably  contains  a  small  quantity  of  a  basic  lime 
compound  which  is  readily  separated  by  filtration,  but  is  greater  in 
quantity  and  more  impure  than  the  trace  which  always  forms  when 
using  the  B.  P.  process,  where  benzene  is  not  employed.  On  com- 
paring the  two  precipitates  (the  B.  P.  and  the  benzene  treated),  the 
latter,  although  heavier,  shows  on  ultimate  titration  no  more,  and  it 
may  be  slightly  less  than  the  former,  and  it  is  concluded  that  there 
is  no  sufficient  reason  for  altering  the  process  in  the  direction  sug- 
gested by  Annett  and  Singh.  (Pharm.  J.,  1918,  101,  318,  through 
The  Analyst,  February,  19 19.) 
Estimation  of  Aldoses  in  Alkaline  Solution. — The  method 
of  H.  Colin  and  O.  Lievin  depends  on  the  fact  that,  under  cer- 
tain conditions,  dextrose  is  oxidized  quantitatively  to  gluconic  acid 
by  iodine  in  alkaline  solution.  The  alkalinity  must  be  sufficiently 
faint  to  eliminate  risk  of  oxidizing  the  alcohol  groups.  The  author 
uses  a  solution  containing  35  Gm.  of  sodium  phosphate  and  50  Cc. 
of  jo  sodium  carbonate  in  a  liter.  To  the  solution  to  be  analyzed 
at  least  three  times  as  much  ^  iodine  are  added  as  will  suffice  to 
oxidize  the  dextrose  believed  to  be  present,  and  then  a  volume  of 
the  alkali  solution  about  double  that  of  the  iodine.  After  an 
hour  the  mixture  is  made  faintly  acid  with  sulphuric  acid,  and  the 
excess  of  iodine  titrated  with  thiosulphate.  Proteins,  tannin,  and 
coloring  matters  which  may  react  with  iodine  must  first  be  removed. 
Usually,  careful  treatment  with  the  least  possible  excess  of  lead 
acetate  will  suffice  to  remove  the  interfering  substances  occurring 
in  the  inulin-bearing  roots,  tubers  and  the  like,  for  the  analysis  of 
which  the  method  was  worked  out.  (Bull.  Soc.  Chim.,  1918,  [IV], 
23,  403-405;  through  The  Analyst,  February,  1919.) 
Iodimetric  Estimation  of  Hypophosphites  and  Phosphites. 
The  method  proposed  by  Boyer  and  Bauzil  is  based  on  the  fact 
that  hypophosphorous  acid  is  oxidized  by  iodine  in  acid  solution  to 
