A  juJ;i!mH3*RM-}      Examination  of  Chloralhydrate.  297 
4.  The  solution  decomposed  quite  rapidly  solution  of  permanga- 
nate of  potassa. 
5.  The  solution  gave  a  faint  cloud  with  Bohlig's  reagent  for  am- 
monia (addition  to  the  liquid  of  about  5  drops  of  a  solution  of  HgCl2 
in  30  parts  of  HO,  will  give  cloudiness  if  free  ammonia  be  present; 
then  addition  of  about  5  drops  of  a  solution  of  KO,  C02  in  60  parts 
HO,  will  give  cloudiness  if  a  salt  of  ammonia  be  present). 
6.  A  sample  was  subjected  to  heat,  the  residue  ignited,  dissolved 
in  a  few  drops  of  dilute  HO.  S03  and  mixed  with  alcohol.  Crystals 
of  KO,  SO,,  were  deposited.  Another  portion  of  the  residue  gave 
the  characteristic  precipitate  with  PtCl2. 
These  results  indicate  the  presence  of  potassa,  formic  acid  and 
traces  of  ammonia.  Having  myself  obtained,  by  chance,  a  sample  of 
Saame's  chloralhydrate,  I  subjected  it  to  a  careful  examination,  and 
have  found  that  my  sample  at  least  was  not  identical  with  Hager's  ; 
for  the  reactions  under  1,  3,  4,  5,  6  gave  all  negative  results.  At  the 
same  time  I  subjected  a  number  of  other  samples  to  examination,  the 
result  of  which  will  be  found  tabulated  below  : 
There  were  9  samples  altogether  ;  2  Merck's,  2  Schering's,  1 
Gehe  &  Co.'s,  1  Saame  &  Co.'s,  1  Marquart's,  2  unknown.  All  gave 
a  clear  neutral  colorless  solution,  except  No.  7,  which  had  a  yellow 
tinge.    None  gave  a  fixed  residue. 
All  solutions  were  made  of  equal  strength,  and  every  reaction  was 
performed  under  equal  circumstances. 
Nitrate  of  silver  solution  was  added  both  to  an  acidulated  and  to  a 
neutral  solution,  and  gave  the  same  result  for  each  sample  in  every 
case. 
To  a  layer  of  HO,  S03  of  1  inch  deep  in  a  test  tube  was  added  1 
grm.  of  the  sample,  and  gentle  heat  applied  to  hasten  dehydration. 
A  portion  of  each  solution  was  acidified  with  a  sriiall  quantity  of 
dilute  HO,  S03  and  solution  of  permanganate  of  potassa  added.  A 
safe  conclusion  from  an  affirmative  reaction  in  this  case  can  only  be 
drawn  if  both  solutions  are  cold,  dilute  and  have  not  long  (not  over 
about  30  minutes)  remained  in  contact.  Otherwise  the  permanganate 
acts  upon  the  chloralhydrate  itself,  and  produces  trichloracetate  of 
potassa. 
A  crystal  of  KI  was  dissolved  in  the  solution  and  solution  of  starch 
added. 
None  of  the  samples  gave  out  any  inflammable  vapor. 
