416 
Characters  of  Antipyrin. 
Am.  Jour.  Pharm. 
Aug.,  1888. 
orange  and  then  red.  The  red  liquid  shows  in  the  spectroscope 
a  band  extending  from  the  middle  of  the  green  to  the  extremity  of 
the  violet.  If  the  one  per  cent,  solution  be  diluted  with  six  times  its 
volume  of  water,  1  cc.  of  the  reagent  will  then  give  a  series  of  tints 
passing  from  deep  orange  red  to  orange  yellow,  yellow,  greenish 
yellow,  and  finally  to  emerald  green.  The  red  liquid  gives  in  the 
spectroscope,  in  a  layer  a  centimetre  thick,  an  absorption  band  that 
extends  from  the  orange  to  the  extremity  of  the  violet.  The  same 
reagent  colors  solid  antipyrin  red. 
Sweet  Spirit  of  Nitre. — The  action  of  this  reagent,  as  pointed  out 
by  Kennedy,"^  appears  to  us  to  approach  that  of  nitrous  acid.  In  the 
cold  the  one  per  cent,  solution  gradually  assumes  a  deep  green  color, 
and  after  several  deposits  emerald-green  crystals. 
Hydriodic  Acid. — Yellow  precipitate  dissolved  by  heat  and  re- 
forming upon  cooling.  Solid  antipyrin  is  easily  dissolved  in  the 
reagent  and  the  solution  evaporated  to  dryness  leaves  a  deep  red 
residue  soluble  in  water.  Chloroform  removes  the  iodine  from  this 
solution,  in  which  antipyrin  is  then  found  unaltered. 
DEHYDRATING  AGENTS. 
Fhosphoric  Acid. — With  the  solution  no  reaction.  Solid  antipy- 
rin, heated  with  this  reagent,  undergoes  instantaneous  decomposition, 
with  disengagement  of  slightly  aromatic  vapor. 
Concentrated  Sulphuric  Acid  dissolves  antipyrin  without  coloration. 
Zinc  Chloride. — White  precipitate. 
ALKALOID  REAGENTS. 
Millon^s  Reagent. — 2  cc.  of  reagent  and  4  cc.  of  1  per  cent,  solu- 
tion in  neutral  solution  give  a  white  precipitate  in  a  yellow  liquid ;  in 
a  solution  acidified  with  hydrochloric  acid,  a  yellow  precipitate  in  an 
orange-yellow  liquid,  the  precipitate  eventually  becoming  red.  In  an 
acid  solution  of  1  in  1000,  a  yellow  precipitate  and  green  liquid.  In 
an  acid  solution  of  1  in  20,000,  a  white  precipitate  and  yellow  liquid. 
Mayer^s  Reagent. — Yell  owlish -white  precipitate  in  the  acid  solution. 
Marme^s  Reagent  (potassio-cadmic  iodide). — Yellowish- white  pre- 
cipitate if  the  solution  be  acid. 
Frbhde^s  Reagent  (impure  molybdic  acid). — Xothing,  even  in  acid 
solution. 
*  Pharmaceutical  Record,  1885,  p.  415. 
