AnM^ch,Sym'}    Br omates  of  the  Cinchona  Alkaloids.  119 
*     BROMATES  OF  THE  CINCHONA  ALKALOIDS. 
By  Claude  Grant  Johnson,  Ph.  G. 
From  an  Inaugural  Essay. 
Bromates  have  of  late  been  receiving  some  attention  as  therapeutic 
agents,  although  they  have  not  yet  come  into  any  general  notice.  Al- 
most all  of  the  inorganic  compounds  of  bromic  acid  have  been  made, 
but  none  of  its  alkaloidal  salts  seem  to  have  been  produced  until  quite 
recently.  It  is  claimed  for  the  bromates  of  the  metals  that  they  give 
all  of  the  effects  of  the  corresponding  bromides  with  the  advantage  of 
being  more  gratefully  received  by  the  system,  which  is  able  to  endure 
them  for  a  longer  time  without  the  unpleasant  after  effects  usually 
following  upon  an  extended  treatment.  They  have  been  used  in 
chorea,  epilepsy,  alcoholism  and  other  diseases  with  good  results. 
"They  are  for  the  most  part  crystallizable,  but  many  of  them 
decompose  when  their  solutions  are  heated.  When  heated  to 
redness,  they  either  give  off  oxygen,  leaving  bromides,  or  give  off 
bromine,  and  part  of  their  oxygen,  leaving  oxides." — (Watts). 
Barium  bromate  is  important  as  being  the  salt  from  which  most  of 
the  others  are  prepared.  It  is  best  made  by  adding  to  a  boiling  solu- 
tion of  potassium  bromate,  sufficient  anhydrous  acetate  of  barium  to 
saturate  it,  and  allowing  to  cool  slowly.  Barium  bromate  crystallizes 
out,  while  potassium  acetate  remains  in  solution. 
Potassium  bromate  was  prepared  by  adding  bromine  to  a  solution 
of  potassium  hydrate,  forming  the  bromide  and  bromate  of  potassium, 
the  bromate  crystallizing  from  the  solution  because  of  its  inferior 
solubility  ("KBr  is  soluble  in  1*6  parts  of  water,  KBr03  in  16*2 
parts." — Walker).  The  bromide  remaining  in  solution  was  procured 
as  bromate  by  adding  the  requisite  quantity  (calculated  from  the  mole- 
cular weights)  of  potassium  hydrate,  and  passing  a  stream  of  chlorine 
gas  through  the  solution  until  saturated,  when  the  bromate  separated 
in  small,  irregular  shaped  crystals,  the  reaction  being  as  follows  : 
KBr+6  KOH-f  3  Cl2=KBr03+6  KC1+3  H20. 
The  product  was  purified  by  recrystallization.  The  shape  of  the 
crystals  depends  upon  the  way  in  which  they  are  made,  from  hot  so- 
lution they  separate  as  needles,  but  by  slow  cooling  are  obtained  as 
four  and  six-sided  plates,  colorless  and  anhydrous. 
Quinine  bromate  has  been  successfully  used  in  some  forms  of  neu- 
ralgia, "  especially  those  in  which  evidence  existed  of  malarious  or 
