254  NEW  PROCESS  FOR  REGENERATING  OXIDE  OE  MANGANESE. 
The  formula  for  this  combination  is  given  as  follows :  Ten 
grains  of  caffein  are  dissolved,  with  the  aid  of  a  gentle  heat,  in 
two  drachms  of  strong  alcohol,  previously  mixed  with  one-half 
drachm  of  water ;  when  cooled,  two  drachms  (by  weight)  of  chlo- 
form  are  added.  The  preparation  is  to  be  protected  from  the 
light.  Thirty  grains  of  this  solution,  or  seventy-five  drops,  con- 
tain one  grain  of  caffein.  It  is  used  by  the  author  in  hemicra- 
nia,  upon  the  occurrence  of  premonitory  symptoms,  in  doses  of 
fifteen  or  twenty  drops,  at  short  intervals.  An  essential  adju- 
vant of  the  cure  or  improvement,  is  a  strict  adherence  to  a 
chiefly  animal"  diet  for  a  longer  period,  especially  by  such  per- 
sons as  are  affected  with  chronic  lesions  of  digestion,  dyspepsia, 
colic,  constipation,  etc. — Detroit  Rev.  of  Med.  and  P harm.,  Feb., 
1868,  from  Wienner  lied.  Presse. 
ON  A  NEW  MANUFACTURING  PROCESS  FOR  THE  PER- 
PETUAL REGENERATION  OF  OXIDE  OF  MANGANESE 
USED  FOR  THE  LIBERATION  OF  CHLORINE  FROM  HY- 
DROCHLORIC ACID.* 
By  Walter  Weldon. 
Every  process,  previous  to  that  to  be  described  in  the  present 
paper,  by  which  it  has  been  attempted  to  regenerate  oxide  of 
manganese  from  the  residues  of  the  manufacture  of  chlorine, 
has  been  performed  in  the  dry  way,  and  has  thus  required  con- 
siderable time,  and  has  involved  not  only  at  least  one — more  or 
less  troublesome  and  costly — furnace  operation,  but  also  several 
removals  of  the  material  from  vessel  to  vessel  and  from  place  to 
place  ;  every  such  removal,  of  course,  entailing  more  or  less  loss,  of 
material.  The  process,  however,  which  is  about  to  be  described  is 
performed  in  the  wet  way,  and  may  be  completed,  even  when  oper- 
ating on  the  largest  scale,  within  as  little  as  one  hour.  Moreover, 
all  the  operations  of  the  process  are  performed  in  the  same  vessel 
as  that  in  which  the  oxide  produced  by  it  is  afterwards  employed 
to  react  with  hydrochloric  acid,  and  from  this  vessel  or  still  the 
manganese  is  never  removed,  so  that  it  is  entirely  free  from  risk 
of  loss  by  removal ;  and  as  it  is  not  subject  to  any  other  cause 
*  Read  before  the  British  Association  at  Dundee. 
