^"''m.Z'^Z^'''  }   ^^^^  Physical  Properties  of  ^inia,  1 23 
0*005  of  quinia  ;  cold  water  dissolves  still  less."  From  this  it  might 
be  inferred  that  the  solubility  of  quinia  in  water  is  pretty  considerable  ; 
for,  calculating  according  to  the  co-efficient  0-005,  one  gram  of  quinia 
would  dissolve  in  200  grams  of  boiling  water,  and  would  require  a 
larger,  but  undetermined,  quantity  of  cold  water.  The  greater  portion 
of  French  standard  treatises  give  different  numbers,  but  unfortunately 
do  not  indicate  their  origin.  The  disagreement  may  be  illustrated  by 
the  following  examples  : 
^.antity  of  Water  required  to  Dissolnje  one  gram  of  ^inia. 
According  to  At  +  15°  C.  At  100°  C. 
Dumas    .....  ....    200  grams. 
Gerhardt     .       ,       .        .  350  grams  .       .        .        400  " 
Pelouze  and  Fremy  .        .        .  400     "    .  .        .        .150  " 
Wurtz         ....  400     "  .        .        .         350  " 
At  +  19°  C. 
Berthelot         ....  480  grams.  .        .        .    200  " 
According  to  the  same  authors  one  gram  of  ordinary  sulphate  of 
quinia,  (C2oH24N202)2H2SOj,  requires  about  750  grams  of  water  (the 
author  has  found  about  755)  at  15*^  C.  to  dissolve  it.  Yxom  which  it 
would  result  that  an  aqueous  solution  of  quinia  upon  being  neutralized 
by  sulphuric  acid,  throws  down,  under  the  form  of  a  deposit  of  insoluble 
sulphate,  nearly  half  the  alkaloid  it  contained  ;  an  inference  manifestly 
incorrect.  In  fact,  the  figure  given  for  the  solubility  of  quinia  in  water 
by  Pelletier  and  Caventou,  and  other  French  chemists,  is  exaggerated. 
Dragendorff,  in  his  "  Toxicologic,"  represents  the  solubility  of 
quinia  in  water  as  i  in  1667  j  this  number,  though  widely  differing 
from  the  preceding,  is  still,  according  to  the  author's  experiments,  con- 
siderably beyond  the  true  one.  Three  experiments  were  made  by  him 
with  pure  quinia,  from  which  all  traces  of  the  other  cinchona  alkaloids 
had  been  carefully  removed.  This  quinia  was  anhydrous,  and  presented 
the  appearance  of  vitreous,  amorphous,  completely  colorless  and  trans- 
parent scales.  Finely  pulverized  in  a  glass  mortar,  and  then  agitated 
during  twenty-four  hours  with  a  large  excess  of  pure  distilled  water, 
previously  made  to  boil,  it  yielded  a  solution  which,  after  being  kept 
during  two  hours  at  a  temperature  of  15°  C,  gave  the  following 
results  : 
Saturated  Sr)lution  Pure  Quinia  dried 
atisOC.  atiio'^C. 
ist  Experiment,      .       .        .       49-8278  grams.  0-025  grams. 
2d  "       .         .       .       .    49-9780     "  0-024  " 
3d  ...       49-6950     "  0-025  " 
