AMMa°yDt  i?74RM"  \   Gleanings  from  the  European  Journals.  237 
the  simplest  method  for  obtaining  the  salt  entirely  neutral;  the  com- 
mercial salt  is  dissolved  in  just  sufficient  water,  its  alkalinity  is  neu- 
tralized with  dilute  sulphuric  acid,  a  small  quantity  of  alcohol  is  added 
to  remove  the  sulphate  of  potassium,  and  the  liquid  filtered  and  evap- 
orated to  crystallize.  The  crystals  are  small,  colorless  and  speedily 
turn  yellow  in  contact  with  the  air.  The  neutral  iodide  seems  to  be 
unable  to  withstand  the  combined  attacks  of  ozone  and  carbonic  acid, 
until  a  certain  degree  of  alkalinity  has  been  established. 
Alfred  Southall,  in  manufacturing  this  chemical,  finds  it  necessary 
to  have  the  solution  as  nearly  neutral  as  possible  in  order  to  obtain 
semi-transparent  crystals  ;  in  the  presence  of  an  excess  of  acid  opaque 
crystals  are  obtained. — Pharm.  Journ.  and  Trans.,  Feb.  21,  p.  669. 
(Our  limited  experience  with  iodide  and  bromide  of  potassium 
points  to  the  necessity  of  having  the  solutions  alkaline  in  order  to 
obtain  opaque  crystals. — Editor  Am.  Journ.  Pharm.) 
Fused  Nitrate  of  Silver,  as  met  with  in  commerce,  is  variable  in 
color  and  often  quite  black.  £.  Bouilhon  regards  as  the  principal 
causes  the  presence  of  some  chloride  of  silver,  the  decomposition  dur- 
ing fusion  of  a  portion  of  nitrate  of  silver,  or  the  presence  of  some  ox- 
ide of  copper.  White  lunar  caustic  is  sometimes  even  more  impure 
in  consequence  of  the  addition  of  potassium  nitrate.  The  author  ob- 
tains unobjectionable  results  by  the  following  manipulation  :  20  grams 
pure  nitrate  of  silver,  five  grams  distilled  water  and  one  gram  pure 
nitric  acid  are  heated,  with  the  precaution  that  the  margin  of  the  so- 
lution is  not  overheated.  After  the  evaporation  of  the  liquid  the 
heat  is  carefully  regulated  and  after  the  salt  has  commenced  to  fuse 
it  is  often  stirred  with  a  glass  rod  to  detach  the  solid  mass  when  ad- 
hering to  the  sides.  When  about  three-fourths  of  the  salt  has  lique- 
fied, it  is  at  once  poured  into  a  perfectly  clean  suitable  copper-mould, 
when  the  sticks  are  obtained  of  unobjectionable  solidity  and  opaque 
whiteness.  The  residue  in  tie  capsule  should  be  treated  with  water 
and  nitric  acid  as  before. — L  Union  Pharm.,  1874,  Feb.,  35. 
Potassium  Nitrate  in  Amarantus.* — A.  Boutin  has  obtained  from 
Amarantus  melancholicus  ruber,  after  drying  at  100^  C,  16  per  ct. 
nitrate  of  potassium,  equal  to  22  grams  of  nitrogen  and  72  grams  of 
potassium  for  each  kilogram  of  the  herb.  A.  atropurpureus  yielded 
22.77  per  cent,  potassium  nitrate,  equal  to  31  grams  of  nitrogen  and 
*  See  also  American  Journal  of  Pharmacy,  1873,  p.  266. 
