AmMa?.ri876.arm'}     Gleanings  from  Foreign  Journals.  131 
GLEANINGS  FROM  THE  FOREIGN  JOURNALS. 
BY  THF  EDITOR. 
Preparation  of  pure  Iodide  of  Potassium. — If  an  aqueous  solution  of  potassium 
iodide,  containing  iodate,  is  treated  with  sulphuretted  hydrogen,  the  iodate  is 
reduced,  some  sulphuric  acid  being  formed  at  the  same  time,  so  that  the  iodide  may- 
contain  1  to  2  per  cent,  of  sulphate,  which  may  be  decomposed  by  barium  iodide. 
A  simpler  and  more  interesting  method  of  purification  consists,  according  to  G. 
Pellagri,  in  shaking  a  warm  solution  of  the  impure  iodide  with  iron  filings,  which 
produces  complete  reduction  of  the  iodate,  no  iron  being  dissolved,  nor  is  iodine 
found  in  the  ferric  oxide  formed.  In  a  concentrated  solution,  the  ferric  oxide  will 
ultimately  exert  an  oxidizing  influence  upon  the  iodide,  and  the  complete  reduction 
of  the  iodate  is  only  possible  if  the  liquid  is  filtered  and  repeatedly  treated  with 
fresh  iron  filings.  Complete  reduction  of  the  iodate  is  effected  in  the  cold  by 
immersing  in  the  liquid  an  iron  and  a  copper  plate,  and  forming  them  into  a 
galvanic  element  by  uniting  them,  outside  of  the  liquid,  with  a  wire  ;  the  iron  only 
becomes  oxidized,  but  no  loss  of  iodine  or  contamination  with  iron  or  copper  takes 
place.  Potassium  bromate  is  likewise  promptly  reduced  by  the  iron-copper  couple, 
but  the  chlorate  is  but  incompletely  acted  upon. 
Powdered  zinc  acts,  at  first,  energetically  upon  potassium  iodate,  but  does  not 
effect  complete  reduction  — Schiveiz.  Woch.f.  Ph.  1875,  No  50,  from  Ber.  Chem.  Ges. 
The  De<vorati-ve  Capsules,  noticed  on  page  31  of  our  January  number,  appear  to 
be  made  principally  of  gelatin.  In  a  warm  place,  or  if  handled  with  moist  fingers, 
they  readily  become  adhesive  and  lose  their  gloss,  at  least  in  the  places  touched. 
They  are  folded  neatly  with  difficulty  only,  and  are,  for  the  apothecary,  very  incon- 
venient, much  more  so  than  the  wafer  capsules,  which  are  readily  closed  with  a  very 
simple  apparatus.  Another  disadvantage  of  the  new  capsules  is  their  unsightly 
appearance,  due  to  their  greyish  color. — Ibid.,  No.  51. 
Iodinized  Cotton. — Cotton,  if  dipped  into  a  concentrated  solution  of  iodine  in 
ether  or  carbon  bisulphide,  retains,  after  drying,  only  traces,  but  no  definite  amount 
of  iodine.  Mehu  impregnates  cotton  with  5  or  10  per  cent,  of  iodine,  by  sprinkling 
it  over  layers  of  cotton,  contained  in  a  bottle,  which  is  then  warmed  in  a  horizontal 
position  in  a  sand  or  water  bath.  As  soon  as  the  warm  air  has  been  expelled,  the 
bottle  is  tightly  closed  ;  the  vapors  of  iodine  penetrate  the  fibres  and  color  the 
cotton  yellow,  the  color  gradually  becoming  deeper,  finally  resembling  roasted 
coffee,  when  the  operation,  which  requires  about  two  hours,  is  finished. — Zeitschr. 
Oesterr.  Apoth.  Ver.,  1876,  No.  3,  from  Jour,  de  Phar.  et  de  Chim. 
Examination  of  Volatile  Oil  of  Mustard. — Hager  observes  that  the  solubility  of 
this  oil,  in  water,  is  variable  ;  old  oil  required  only  120,  fresh  oil  about  230  parts  of 
water  of  medium  temperature  for  solution.  Agitated  with  three  times  its  volume 
of  concentrated  sulphuric  acid,  the  mixture  remains  clear  and  becomes  thick  like 
syrup,  after  12  hours,  or  is  converted  into  a  crystalline  mass. — Phar.  Cent.  Halle, 
1875,  No-  43- 
Elisa  Galeers  liquid  for  promoting  the  growth  of  the  hair  is  a  filtered  mixture  of 
15  grams  ammonia  water,  20  grm.  glycerin,  50  grm.  alcohol,  10  drops  each  of  the 
oils  of  rue,  lavender  and  bergamot,  and  200  grms.  of  water. — Ibid. 
