Am.. lour  Pharm 
Feb.,  1883. 
I    Analytical  Researches  o/nd  Investigations.  89 
ANALYTICAL  RESEARCHES  AND  INVESTIGATIONS. 
Collated  ey  Pkof.  Frederick  B.  Power,  Ph.  D. 
A  New  Method  for  the  Recognition  of  Blood  Stains.  ByG.  Filippi. — 
It  occasionally  happens  that  the  identification  of  blood  stains  by  the 
formation  of  hsematin  crystals  is  not  successful  when  the  stains  have 
been  partially  washed  out  or  altered  by  decomposition.  In  such  cases 
the  author  takes  advantage  of  the  iron  contained  in  the  blood  as  a 
means  for  their  identification.  The  portions  of  the  tissue  which  con- 
tain the  blood  stains  are  macerated  for  24  hours  in  95  percent,  alcohol 
to  which  one-twentieth  of  its  weight  of  sulphuric  acid  has  been  added. 
The  alcohol  is  then  poured  off,  and  fresh  portions  added  until  it  ceases 
to  assume  a  red  color,  after  which  the  alcohol  is  made  strongly  alkaline 
by  the  addition  of  an  alcoholic  solution  of  ammonia.  The  liquid  is 
then  heated  upon  the  water-bath  to  boiling,  and  filtered,  when  a 
residue  of  ammonium  sulphate  will  remain  upon  the  filter,  which  is 
washed  with  the  alcoholic  solution  of  ammonia.  The  liquid  is  then 
evaporated,  and  the  residue  ignited.  If  h^ematin  be  present,  there 
appear  on  the  sides  of  the  porcelain  capsule  reddish  spots,  which, 
when  dissolved  in  a  drop  of  nitro-hydrochloric  acid,  yield  with  potas- 
sium ferrocyanide  and  sulphocyanide,  the  well-known  reactions.  It  is 
recommended,  also,  to  perform  a  control  experiment  with  a  portion  of 
the  tissue  under  examination  which  is  free  from  stains. —  Chem.  Tjel- 
tung,  No.  81,  p.  1126,  from  Giorn.  Farm.  Chim.,  31,  p.  481. 
Yoluinetric  Estimation  of  Iodide  of  Potassium.  By  P.  Carles. — The 
volumetric  method  of  estimation,  recommended  by  Personne,  the 
author  finds  to  give  perfectly  satisfactory  results  when,  in  the  place  of 
water,  17*5  per  cent,  alcohol  is  employed  for  the  solution  of  the  potas- 
sium iodide  and  mercuric  chloride. 
As  commercial  potassium  iodide  frequently  contains  small  amounts 
of  potassium  iodate,  carbonate,  chloride,  and  bromide,  and  sodium 
chloride,  and  it  being  of  importance  to  know^  the  influence  of  these 
bodies,  the  following  two  mixtures  were  prepared  by  the  author,  which 
were  titrated  in  alcoholic  solution  with  mercuric  chloride  : 
I.  II. 
Potassium  iodide,  .  .  70  per  cent.  70  i)er  cent. 
Potassium  chloride,  .         .         .     10      "  20  ^' 
Potassium  bromide,  .  .  10  "  — 
Potassium  iodate,  .  .  .  5  "  5 
Potassium  carbonate,      .          .           5       "  5  " 
