GLEANINGS  FROM  GERMAN  JOURNALS. 
399 
of  potassium  iodide  in  5 — 6  times  its  weight  distilled  water  and 
oversaturated  with  free  iodine  and  a  solution  of  potassium  hy- 
drate of  about  10  per  cent,  strength.  To  the  liquid  to  be  exam- 
ined 5 — 6  drops  of  the  latter  solution  are  added.  After  warming 
to  about  50°  C.  so  much  of  the  potassium  iodide  solution  is  added 
drop  by  drop  that  its  color,  after  gentle  agitation,  remains  yel- 
lowish-brown ;  then  the  liquid  is  carefully  discolored  by  the  ad- 
dition of  a  few  drops  of  the  potassium  hydrate  solution.  When 
set  aside  the  iodoform  crystals  deposit,  and  arc  recognized  under 
the  microscope. 
The  process  is  obvious  ;  it  is  elfected  not  alone  by  ethyl  alco- 
hol, but  by  a  number  of  dilferent  substances,  among  which  are 
aldehyde,  acetone,  gummi,  sugar,  lactic  acid,  methyl  alcohol^ 
propyl  alcohol,  and  many  volatile  oils.  The  formation  of  iodo- 
form is  not  produced  by  amyl  alcohol,  ether,  ethyl  chloride,  chlo- 
roform, chloral  hydrate,  glycerin,  phenol,  and  by  acetic,  benzoic, 
butyric,  citric,  formic,  oxalic,  succinic,  valerianic  and  tartaric 
acids. 
Detection  of  Alcohol  in  Chloroform  and  Chloral  Hydrate. 
This  test  is,  according  to  Hager,  superior  to  any  for  the  de- 
tection of  alcohol  in  chloroform  and  chloral  hydrate  : 
Chloroform. — To  determine  the  presence  of  alcohol  in  chloro- 
form 2  vol.  chloroform  are  mixed  with  5  to  10  vols,  of  water,  of 
about  50°  C.  The  liquid,  after  some  shaking,  is  poured  on  a 
filter  previously  completely  saturated  with  water.  The  filtrate 
is  then  examined  as  described  above.  After  12 — 24  hours  de- 
positing the  sediment  is  examined  under  the  microscope. 
Chloral  Hydrate. — Chloral  forms  with  ethyl  alcohol  chloral 
alcoholate,  corresponding  to  chloral  hydrate  in  its  chemical  and 
physiological  properties.  Since  the  equivalent  weight  of  ethyl 
alcohol  is  five  times  greater  than  that  of  water,  it  is  of  consid- 
erable pecuniary  advantage  to  the  manufacturer  to  bring  the 
chloral  alcoholate  into  the  market  instead  of  the  hydrate  ;  besides 
the  former  crystallizes  finer  and  more  solid. 
The  examination  is  made  with  a  solution  of  the  sample  in  dis- 
tilled water,  in  the  above  given  mode.  When  discoloring  the 
iodinized  liquid,  each  drop  of  the  potassium  hydrate  solution 
