Asepn,  iP873.RM1  Manufacture  of  Chloral  Hydrate,  etc.  413 
ON  THE  MANUFACTURE  OF  CHLORAL  HYDRATE  IN 
GERMANY. 
By  Gustav  Detsenyi. 
The  extraordinary  reduction  in  the  price  of  hydrate  of  chloral 
since  1869 — from  90  thalers  per  kilo  to  3  thalers— is  easily  explained 
when  we  consider  the  enormous  increase  in  its  production  which  the 
demand  for  it  has  created.  Early  in  the  year  1869,  Dr.  Liebreich, 
of  Berlin,  introduced  it  as  a  medicine,  and  thus  gave  an  impulse  to 
the  invention  of  simpler  and  cheaper  methods  of  preparing  it,  and 
to-day  its  manufacture  has  reached  such  a  state  of  perfection  that  we 
can  scarcely  imagine  any  essential  improvement  in  it  possible.  Three 
years  ago  it  was  scarcely  possible  to  prepare  a  few  pounds  of  chemi- 
cally pure  chloral  hydrate  in  as  many  weeks  ;  now  500  pounds  per 
day  are  made  in  a  few  German  chemical  works. 
The  principal  part  of  the  operation  is  passing  chlorine  gas  into  96 
per  cent,  alcohol.  The  chlorine  is  made  from  muriatic  acid  and  black 
oxide  of  manganese.  In  Schering's  establishment,  in  Berlin,  a  large 
crock  of  stoneware,  four  or  five  feet  high,  is  half  filled  with  the  black 
oxide  of  manganese,  and  muriatic  acid  is  allowed  to  flow  in.  A  de- 
livery tube  of  lead  and  glass  conducts  the  chlorine  thus  generated  to 
a  Woulfe  bottle,  where  it  passes  through  water,  and  thence  into  a 
carboy  containing  120  to  150  pounds  of  96  per  cent,  alcohol.  A 
second  carboy  is  also  connected  with  the  first,  in  order  to  collect  the 
hydrochloric  acid  formed. 
The  chlorine  is  passed  uninterruptedly  for  twelve  or  fourteen  days, 
until  the  alcohol  is  warmed  to  60°  or  70°  C,  and  acquires  a  density 
of  41°  Baume\  This  forms  one-half  of  the  operation,  and  requires 
cautious,  conscientious  and  experienced  workmen.  Especial  attention 
must  be  devoted  to  the  luting  and  to  refilling  the  chlorine  generator. 
The  apparatus  is  luted  with  a  paste  of  bran  flour  and  water,  and  the 
cover  of  the  crock  is  loaded  with  heavy  weights.  Before  renewing 
the  charge  of  black  oxide  of  manganese,  the  chloride  of  manganese 
solution  is  drawn  off  by  a  cock  near  the  bottom,  and  the  chlorine  in 
the  vessel  allowed  to  escape  by  a  delivery  tube  that  goes  up  through 
the  roof  into  the  open  air.  In  the  Berlin  establishment  above  men- 
tioned there  are  forty  of  these  apparatus  at  work,  producing  three 
carboys  of  chloral  per  day. 
The  second  pare  of  the  operation  consists  in  the  purification  of  the 
•chloral  hydrate.    For  this  purpose  the  chlorated  alcohol,  before  ob- 
