414 
<,'haraderB  of  Antipyrin. 
( Am.  Jour,  Phann. 
C       Aug.,  1888. 
have  examined  from  this  point  of  view  thi-ee  samples  of  different 
brands  and  have  found  Knorr's  antipyrin  to  melt  at  lOo"  C.^  anti- 
pyrin from  the  house  of  Mialhe  to  melt  at  106°  C.  and  antipvrin 
from  the  house  of  Castheiaz  at  107°  C.  A  partial  explanation  of 
the  cause  of  these  divergencies  has  been  foimd  in  the  considerable 
hygroscopic  pro}:»erty  of  antipyrin.  The  above  mentioned  three 
products,  dried  in  an  oven  for  six  hours  at  100^  C,  and  then  over 
sulphuric  acid  for  twelve  hours,  lost  on  an  average  0*6  per  cent,  of 
their  original  weight.  Exposed  to  the  air  they  very  ra^^idly  absorbed 
moisture  and  recovered  weight.  The  melting  point  of  the  products 
proved  indeed  to  be  identical ;  when  completely  dried  they  melted  at 
110^  C. 
SOLUBILITY. 
Soluble  in  its  own  weight  of  water  at  12"  C,  and  with  heat  in 
half  its  weight  of  water.    The  aqueous  solution  is  neutral. 
Soluble  in  twice  its  weight  of  absolute  alcohol,  the  solubility  in 
this  menstruum  augmenting  with  the  degree  of  dilution,  so  that  it 
dissolves  in  its  own  weight  of  eighty  per  cent,  alcohol. 
Soluble  in  its  weight  of  amylic  alcohol,  in  fifty  times  its  weight  of 
ether,  in  one  and  a  half  times  its  weight  of  chloroform,  and  nearly 
insoluble  in  light  petroleum  spirit  and  benzin. 
It  is  also  very  soluble  in  sulphuric,  hydrochloric,  nitric  and  phos- 
phoric acids,  with  which  it  forms  salts  soluble  in  water. 
OXIDIZING  AGE2s"TS. 
Potassium  Chlorate  and  Hydrochloric  Acid. — Upon  boiling  the 
liquid  becomes  reddish-yellow ;  upon  cooling,  minute  bright  red  oily 
drops  separate.  This  red  hquid  is  taken  up  by  chloroform,  which  it 
colors  greenish  orange-yellow.  Ether  removes  the  coloring-  matter 
from  chloroform  and  is  colored  golden-yellow. 
Potassium  Ferricyanide  and  Hydrochloric  Acid. — Upon  boiling 
becomes  dark  greeo.  It  deposits  upon  the  sides  of  the  tube  a  pre- 
cipitate that  in  transmitted  light  shows  an  ultramarine  color  and  in 
reflected  light  a  bluish-green. 
Chromic  Anhydride. — In  the  cold  an  orange-yellow  precipitate,  the 
color  of  which  gradually  darkens.    Precipitate  dissolved  by  heat. 
Potassium  Permanganate. — In  the  cold  reduction  takes  place.  The 
liquiii  becomes  purple-red,  then  brown,  and  finally  colorless,  with  a 
deposit  of  oxide  of  manganese. 
