162 
CHEMICAL  COMPOSITION  OF  QUINIDINE. 
ish-green  resinous  substance,  together  with  quinine,  (according 
to  the  test  with  chlorine  water  and  ammonia,)  and  very  pro- 
bably, also,  a  third  substance,  containing  a  larger  proportion  of 
carbon. 
The  following  operations  were  performed  in  the  laboratory  of 
Prof.  Will : 
In  order  to  obtain  the  base  in  a  perfectly  pure  state,  the  rough 
quinidine  was  dissolved  in  alcohol  of  90  per  cent.,  and  the  solu- 
tion allowed  to  evaporate  spontaneously  in  the  air,  when  a  green- 
ish-yellowish resinous  substance  soon  appeared  on  the  walls  of 
the  vessel.  The  most  beautifully  formed  crystals  were  then  se- 
lected, washed  with  alcohol,  and  re-dissolved  in  spirit  of  wine, 
when  the  same  greenish-yellow  substance  was  deposited.  The  re- 
crystallization  having  been  performed  five  or  six  times,  until  the 
yellow  substance  was  no  longer  perceived,  and  the  proportion  of 
carbon  in  the  base  not  yet  proving  uniform,  the  crystals  obtained 
after  five  or  six  times  repeated  re-crystallization  wrere  finely  pow- 
dered and  shaken  with  ether,  until  all  reaction  of  quinine  disap- 
peared, and  the  proportion  of  carbon  remained  constant. 
If  quinidine  be  dissolved  in  spirit  of  wine  of  90  per  cent.,  and 
the  solution  left  to  spontaneous  evaporation,  it  forms  colorless, 
hard  prisms,  shining  like  glass,  with  edge  angles  of  86°  and  94°  ; 
the  planes  of  the  prisms  are  strongly  striped,  these  stripes  being 
also  observable  on  the  planes  of  truncation  of  the  more  obtuse 
edges  of  the  prism;  and  in  the  direction  of  the  latter  planes  the 
crystals  admit  of  perfect  cleavage.  The  crystals  are  terminated 
by  shining  planes,  which  converge  at  114°  30',  and  are  applied 
on  the  more  acute  edges  of  the  prism. 
The  rather  hard  crystals  are  easily  rubbed  to  a  snow-white 
powder,  which  becomes  electrical  by  friction.  If  the  crystals  be 
heated  in  a  platinum  crucible  over  the  flame  of  spirit  of  wine, 
they  at  first  retain  their  brilliancy  and  form,  and  fuse  without 
decomposition,  and  without  yielding  water,  at  175°  C.,*  and  form 
a  clear,  wine-yellow  liquid,  which,  when  cold,  solidifies  into  a 
greyish-white  crystalline  mass.  If  the  heat  be  increased  above 
175°,  the  wine-yellow  fluid  ignites',  burns  with  a  red,  vividly 
flaring,  strongly  sooty  flame,  evolving  at  the  same  time  an  odor 
*  £A11  the  temperatures  expressed  in  this  paper  are  according  to  the 
ecntigrade  scale. — Ed.] 
