114 
Chloral. 
5  Am.  Jour.  Pharm. 
I    March  1, 1871. 
soluble  chloral.  The  sp.  gr.  of  soluble  chloral  is  1*502.  By  degrees 
it  thickens,  and  is  sometimes  transformed  suddenly  into  soluble  chloral, 
evolving  a  large  amount  of  heat. 
When  we  mix  anhydrous  chloral  with  water,  we  obtain  in  a  short 
time  acicular  crystals  of  hydrate  of  chloral,  this  body  being  distin- 
guished from  ordinary  chloral  by  containing  one  molecule  of  water. 
Its  formula  is  C2C13HO+H20. 
This  method  is  the  one  alone  authorized  by  Dr.  Liebreich,  of  Ber- 
lin,* who  took  out  a  patent  in  July,  1869,  for  the  sole  use  for  anaes- 
thetic purposes  of  chloral,  hydrate  of  chloral,  and  trichloroacetic  . 
acid,  (C2HCI3O2). 
The  physiological  and  therapeutical  experiments  made  by  Liebreich 
led  to  the  introduction  of  this  product  as  a  medicinal  agent,  and  since 
he  has  published  his  formula,t  with  the  results  of  his  experiments,  I 
think  we  should  fix  upon  his  method  as  the  orEiciNAL  one.  The 
superiority  of  the  hydrate  of  chloral  manufactured  under  his  super- 
vision I  shall  prove  to  you  (i.  e.,  if  the  larger  froportion  of  chloroform 
produced  hy  alkaline  reagents  from  the  chloral  compound  employed 
is  to  be  the  test,  which  is,  I  think,  self-evident.)  He  tells  us  that 
numerous  experiments  show  that  this  method  is  far  the  most  trust- 
worthy. 
Chloral  is  obtained  in  other  ways ;  for  instance,  by  the  method  of 
Staedeler,  from  starch,  by  distillation  with  hydrochloric  acid  and 
dioxide  of  manganese,  formic  acid,  carbonic  acid  and  other  bodies 
accompanying  it ;  but  Liebreich  states  he  has  made  experiments  with 
this  preparation  and  finds  it  is  not  to  be  depended  upon  in  its  action, 
from  the  great  diiOficulty  of  preventing  the  formation  of  other  com- 
pounds, especially  chlorides  of  carbon,  which  serve  to  contaminate 
the  chloral  and  render  its  administration  dangerous. 
It  was  contended  by  M.  J.  Personnel  that  the  hydrate  of  chloral 
prescribed  by  M.  Roussin  as  pure,  was  nothing  more  than  a  compound 
of  chloral  and  alcohol.  Difi'erences  being  observed  in  the  physical 
properties  of  the  preparation  made  by  Liebreich  and  that  made  by 
Koussin,  it  was  found  that  they  were  two  entirely  distinct  compounds, 
-which  was  fully  confirmed  by  an  appeal  to  analysis.  Theoretically, 
^  "  L'Hydrate  de  Chloral."    Oscar  Liebreich. 
f  Idem, 
%  Journal  de  Pharmacie  et  de  Chimie. 
